Cannabis Grow

As a volunteer mentioned, patients are “prescribed by psychiatrists to come and garden.” Additionally, healthcare workers and veterans participating in the VA’s Compensated Work Therapy Program use the garden for growing food and taking breaks. Visitors are welcome to enjoy the garden at any time. Unlike most other UA sites that will be mentioned in this chapter, there is no gate at the front entrance, though there are security cameras monitoring the property. Signs instruct visitors not to pick crops without permission. There are accessible pathways for those with mobility-aiding devices , a restroom, benches, a barbecue grill, a building with a refrigerator, and a large gazebo and seating area. Eagle Scouts from the Boy Scouts of America installed raised garden beds and a flagpole for the garden. Figure 13 shows a large greenhouse surrounded by California native plants, shade-providing trees, chairs, and rainwater barrels.In 2023, the Surfrider Foundation donated six 50-gallon rain barrels to collect rainwater, to water plants and prevent storm water pollution from runoff. The rain barrels were up cycled using mosquito netting, barrels used to ship food items, and PVC pipes and spouts . These amenities helped gardeners plant a variety of edible crops and about 70 fruit trees, such as bananas, pears, and persimmons. The Patient Garden is also decorated with cacti, roses, bird feeders, a rock garden full of painted stones, cannabis drying curing and a sensory garden with plants meant to see, smell, and touch.The Long Beach Community Garden was first established in 1976 at the abandoned Honor Farm .

Originally, LBCG was 6.5 acres with 218 garden plots, located between the Interstate 605 and East Carson Street. However, city officials asked LBCG to relocate in 1996, following the demolition of a Naval hospital and construction of a shopping center, which included Walmart and other stores . On December 1, 1997, LBCG opened its new 8.5-acre location, which is between the 605 freeway and El Dorado Park, on Spring Street in the 90815 ZIP Code. With 300 plots each measuring 20’ x 30’, LBCG is the largest community garden in the city. LBCG is managed by the Long Beach Community Garden Association , a not for-profit organization with no paid staff. A board of eight members oversees the LBCG’s budget, which goes toward the maintenance and enhancement of the garden. Gardeners pay an annual membership fee of $160 and are required to complete four hours of community service per year, to maintain common areas of the garden. Only LBCG members and authorized individuals can enter. The garden is protected by a locked gate, which features a remote-controlled entryway for cars and large trucks for trash collection and mulch delivery. The photograph in Figure 14 shows a tree in front of one of the many paved roads inside LBCG, which allows accessibility for both vehicles and gardeners.LBCG features a large gazebo, benches for sitting, a storage shed, and a fruit tree orchard. Gardeners may donate food from their garden plots and the fruit orchard to the Food Bank Collection Station. The food from this station is distributed to a variety of local charities, such as Long Beach Rescue Mission. LBCG’s fruit orchard has over 100 trees, including but not limited to: avocado, banana, cherimoya, grapefruit, lemon, lime, loquat, kumquat, orange, peach, pear, persimmon, pineapple guava, and pomegranate. There are several varieties of fruit and hybrids such as aprium, nectaplum, and pluerry . The QR codes direct to the official LBCG website with information on each tree.As shown in Table 3, five LBO community gardens are located on city property and four are located on land owned by a private owner .

The largest LBO garden was Zaferia Junction, which is 1.4 acres, over 20 times larger than Orizaba Park, the smallest garden . All LBO gardens provided hoses, a communal shed for tools, a compost area, and a picnic arbor for gardeners to sit in the shade and enjoy meals, and most of the gardens are accessible for those with disabilities. A few gardens feature special amenities, such as a hive for beekeeping, portable toilets, fruit trees, and herb beds. Zaferia Junction has a sensory garden and an earth oven for cooking food outdoors. At the time of writing, 250 of 281 plots were rented. Six of the gardens have a waitlist for renting a garden plot, with the wait time ranging from six months to four years. LBO prioritizes renting plots to low-income families who may otherwise lack access to organic produce, Long Beach residents or those who live near an LBO garden, and those who have no other opportunity to garden. Requirements for plots vary on the property owner. For example, gardens located on land owned by Long Beach’s Department of Parks, Recreation & Marine prioritize gardeners who live within walking distance. Gardeners pay a minimum of $55 per six-month season for plots smaller than 10’x8’. The fee for larger plots is $0.70 per square foot . LBO gardeners are required to sign a rental agreement and waiver of liability, maintain their plot, and complete a minimum of 10 hours of community work per six-month season. Each garden is secured by a locked fence, which gardeners receive the code for when they rent their plot. The gardens are open to volunteers and community members on Saturday workdays, which involve weeding, construction projects, and maintaining spaces outside the garden plots, such as walkways or areas near the fence. For example, for the Captain Charles Moore Urban Community Garden located on Long Beach Blvd, which began construction in April 2023, volunteers built the shed, arbor, and raised garden beds, as well as a swale to capture rainwater and direct moisture to the garden .

Gardeners may also complete their volunteer hours on Wednesdays at Zaferia Junction to assist with harvesting, washing, and sorting produce, which is donated to California State University, Long Beach’s student pantry .Though most gardeners grew the previously mentioned crops that thrive in Southern California’s climate , there were many notable crops unique to each garden site. For example, one gardener at Zaferia tended to a variety of fruit trees, including peaches, apples, and hybrids like nectaplum , pluot , and bubblegum aprium . Pacific and 6th had banana, papaya, and loquat trees, as well as perilla and other crops planted by Asian gardeners. Gardeners at Grace Park grew longevity spinach, Malabar spinach, and hoja santa , an herb native to Mexico. Many LBO gardens also had herbs such as cilantro, basil, sage, thyme, and oregano, and grew grapes from their picnic arbor.Three small community gardens are managed by Century Villages at Cabrillo, Inc., an independent nonprofit entity affiliated with Century Housing Corporation. Founded in 1997, Century Villages at Cabrillo is a 27-acre campus community that aims to provide permanent housing to veterans, families, and individuals to prevent homelessness. CVC is located at 2001 River Avenue Long Beach, CA 90810. The Magic Garden, David’s Garden, and American Indian Changing Spirits Garden at CVC are free for residents, vertical growing systems with a “first come, first served” policy. Over 1,797 people reside at CVC, including 669 veterans . The Magic Garden, which was formerly known as the CVC Veteran’s Gardening project, was originally built by the late veteran and former Navy SEAL Tony M. in 2013. Due to CVC construction, the garden was moved in 2017, and is available to all residents. The Magic Garden offers 22 raised garden beds, where gardeners planted several edible crops. There is also a common area with papaya and banana trees. The Magic Garden also offers a sensory garden and meditation labyrinth .A CVC Occupational Therapist , who helps residents with disabilities or changes in their physical and mental capabilities, oversees the garden. To recruit volunteers, they partnered with PATH and OT internship programs from University of Southern California and California State University, Dominguez Hill’s Occupational. David’s Garden and the American Indian Changing Spirits Garden are adjacent to each other, next to two barbecue grills and five picnic tables with benches. David’s Garden, which has four raised garden beds and in-ground plots, is maintained by Sowing Seeds of Change, which operates its own urban farm about three miles away from CVC. Produce from David’s Garden supplements CVC’s weekly farm stand, which provides fresh, locally grown produce to residents. American Indian Changing Spirits, an agency which served 132 adults in 2022, provides culturally appropriate alcohol and drug education, counseling, and recreation for American Indian men and women. Their garden supplements social and cultural activities.I visited two gardens managed by the City of Long Beach: the health department’s Peace Garden and the Michelle Obama Neighborhood Library Learning Garden. Information on the exact size of each garden was unavailable, but they are roughly the size of LBO’s smallest gardens . The Peace Garden is inside Martin Luther King Jr. Park at 1950 Lemon Ave, Long Beach, CA 90806. It is adjacent to Long Beach’s Black Resource Center and the Central Facilities Center of the Nutrition Services Division WIC Program, which provides public services related to the Special Supplemental Nutrition Program for Women, Infants, and Children . LBDHHS established the Peace Garden in 2010 as part of the Healthy Active Long Beach Project, to promote healthy eating and physical activity through educational activities.

The garden has eight plots, a greenhouse, compost bin, and several fruit trees: plantains, figs, mulberries, and pomegranates. Local community residents can register for a garden plot at no cost. LBDHHS prioritizes households that reside in the 90806 or 90813 ZIP Codes, are eligible for federal nutrition programs , and/or have children who attend a school served by Healthy Active Long Beach. The garden is open on weekdays from 8:00 AM to 5:00 PM. LBDHHS staff provide free plants and grow produce around the perimeter of the garden for community members to harvest. For example, Figure 18 shows a table with free cacti and seedlings, next to a patch of squash.To learn more about UA sites located at schools, I visited gardens built by the nonprofit organization, Ground Education. Ground Education provides gardening curriculum to the LBUSD, which has 47 elementary schools and six K-8 institutions . In 2024, Ground Education operated in 24 LBUSD schools, over half of all schools in the district. The nonprofit intentionally selects schools in areas with less access to green space, and so their gardens are “mostly concentrated in North, Central and West Long Beach” . Founded by Holland Brown and Karen Taylor in 2008, Ground Education was originally created to revitalize former school gardens that were abandoned or needed maintenance. Originally a two-woman team, Ground Education now employs 29 staff members, including Garden Educators at each school site and a team that builds and maintains school gardens . Ground Education designs and builds new school learning gardens, teaches monthly outdoor lessons for transitional kindergarten through 8th grade, develops educational programming for after-school and summer programs, and provides workshops for partner community gardens. All Ground Education gardens feature the following amenities: a portable hand washing sink, rotating compost bin, storage shed, bird feeder, and benches for students.The gardens also have a small nature path with tree stumps and native California plants for students to explore. Ground Education’s Garden Educators deliver hands-on educational activities for TK-8 students to plant wheat, peas, lettuce, fava beans, carrots, beets, green onions, and other crops. Each class participates in monthly one-hour lessons during their usual class time. In addition to learning about where food comes from and tasting the food they grow, students hatch chickens in their classrooms, discover the importance of decomposers, and gain skills such as pickling vegetables, making pesto from carrot tops,milling flour from wheat, and using a solar oven to melt cheese on nachos with heat from the sun. Figure 22 shows Fremont Elementary’s main garden, which has 14 raised garden beds.Heritage Farm was once Gladys Avenue Urban Farm, previously owned by LBO founder Captain Charles Moore. The 8,000-square-foot parcel of land was sold to the current owner with the stipulation that it would continue to be used for UA. As of June 2022, Heritage Farm is managed by Chef Lauren Pretty, owner of the restaurant, Heritage. The farm supplies Heritage with a variety of herbs, flowers, fruits, and vegetables. Some notable crops included cucamelons, passion fruit, longan, Brazilian cherries, mulberries, “1,500-year-old cave beans” , and cardoons .

The City of Long Beach, located in Los Angeles County of Southern California, is home to a diverse population of about 451,000 people . Long Beach is 20 miles south of downtown Los Angeles and borders the west side of Orange County . Out of 88 cities in LA County, Long Beach is the second most populous after Los Angeles, which has 3.8 million residents . The land area of Long Beach accounts for just 1.2% of land in LA County . However, the coastal city is well-known for the Port of Long Beach , the Queen Mary , California State University, Long Beach, and the Aquarium of the Pacific . This dissertation focuses on the City of Long Beach due to its high prevalence of community gardens compared to other cities in LA County. A 2013 comprehensive report of LA County urban agriculture identified the city as having 19 community gardens, one-sixth of the county’s total . As of 2024, Long Beach has about 28 community gardens according to multiple sources . This suggests that about 22% of the county’s estimated 125 community gardens are in Long Beach . There is evidence that UA can increase communities’ access to green space and food, while also creating opportunities for socialization and the exchange of resources and knowledge . The high prevalence of community gardens in Long Beach may result from local efforts to increase access to food. Compared to LA County, Long Beach has higher rates of food insecurity, pipp horticulture meaning that residents “lack consistent access to enough food for an active, healthy, life” . The food insecurity rate in Long Beach is 10% more than that of the county .

Communities of color who live in North, Central, and West Long Beach are at highest risk of being food insecure . These areas include the 90805, 90806, 90807, 90810, 90813 ZIP Codes , where communities are disproportionately burdened by disease and health conditions, such as asthma, diabetes, and hypertension .Existing health inequities in Long Beach may be explained by housing practices enacted nearly a century ago. According to the City of Long Beach’s Historic Context Statement, neighborhoods were shaped by redlining, the restriction of housing loans based on race . Federal Housing Association and private banks implemented redlining in the 1930s, preventing people of color from purchasing or renting in certain areas. Although the U.S. Supreme Court ruled in 1948 that such housing restrictions could not legally be enforced, redlining continued into the 1970s. Housing discrimination even affected professors of color at Long Beach State College, presently known as California State University, Long Beach. Despite being recruited to teach at the university, they were not allowed to buy homes near the campus, located on the East side of Long Beach . Figure 2, a census tract map from 1950, shows that most African American and other non-White residents were concentrated in Central and West Long Beach. The purple tracts represent areas where both groups resided .Before Long Beach’s incorporation as a city, its demographics were impacted by colonization. Present day Long Beach was originally the traditional and ancestral territory of the Tongva/Gabrieleño and the Acjachemen/Juaneño indigenous peoples . Puvungna, once a large settlement, was located where California State University, Long Beach stands today. It continues to hold spiritual and cultural significance to several tribes .

The Tongva , consumed a variety of meats, insects, and plants . Instead of maize, which was more popular in the Colorado River region, the Tongva favored nutrient-rich acorns, high in both fiber and fat . They also consumed a meal made from ground seeds of islay , cholla cactus seeds, wild sunflower seeds, chia seeds and shoots, and clover . In 1542, Spanish explorer Juan Rodriguez Cabrillo seized land from the Tongva tribe . European colonization resulted in the spread of new diseases, death, and displacement of the Tongva and other indigenous peoples. Over time, Spanish settlers established ranchos throughout the region to raise horse, cattle, and other livestock. One of the largest ranchos in California was owned by retired soldier Manuel Nieto, who received 300,000 acres of land in 1784 as a reward for his military service . Nieto’s rancho spanned from the Los Angeles River to the Santa Ana River. After his death in 1804, Nieto’s children inherited the land. During their joint ownership of the rancho, California became part of Mexico in 1821 after the country gained independence from Spain . In the early 1830s, Nieto’s family divided their land into six parcels. The United States claimedCalifornia as a territory in 1848, and in 1950, California became the 31st state . As California assimilated into the U.S., Nieto’s rancho became further divided and sold to American ranchers. For example, the 27,000-acre Rancho Los Cerritos, Ranch of the Little Hills, was owned by Nieto’s daughter Manuela Cota, then sold after her death to Massachusetts-born John Temple in 1843 . Temple used the land to raise cattle for their hides and tallow. Although he mainly resided in Los Angeles for his mercantile business, Temple lived at Rancho Los Cerritos during the summer, and built a two-story adobe headquarters and garden. After retiring, Temple sold Rancho Los Cerritos to Flint, Bixby & Co. in 1866. The Bixby family kept 30,000 sheep to provide wool. However, the sheep industry declined during the late 1870s, and so Jotham Bixby began to lease and sell portions of the property. Over time, the cities of Long Beach, Bellflower, Paramount, Signal Hill and Lakewood were founded on Los Cerritos lands .

Agriculture was an important part of Long Beach’s early economy that drew long-term settlers. 19th century farmers raised cattle and sheep, and grew flowers, fruits, and vegetables such as corn, beans, barley, and alfalfa . During the 20th century, the city placed a stronger focus on tourism and industry, advertising Long Beach as a seaside resort town. This attracted seasonal tourists but marked an overall decline in agriculture. The city’s population increased due to national and regional immigration and the discovery of oil. Landowners sold large tracts of real estate for industrial, commercial, and residential expansion . Many of Long Beach’s UA sites from the last century were developed from vacant land, either by city officials or local organizations. One example, Rancho Esperanza, was originally created to extract labor from Long Beach’s jail population, which overflowed with a “staggering number of drunks” . The idea was initially proposed in 1949 by city prosecutor Kenneth Sutherland and endorsed by court judge Charles Wallace police chief William Dovey. Rancho Esperanza became known as the “Honor Farm.” In 1954, “42 alcoholics and assorted vagrants and traffic law violators” were sent to the Honor Farm, and after eight months, grew enough food to feed themselves and the inmates back at the city jail . Though the farm was abandoned in the 1970s, it was later converted into a community garden. In 1974, the Long Beach Parks Department was requested by the city council to study how vacant city properties could be converted into private vegetable plots . In January of 1976, the City Council approved the Honor Farm community garden, which was described as “heaven to a gardener,” featuring 218 garden plots, compost bins, rustic building, and a small orchard. The Long Beach Community Garden Association was organized in May of that year to supervise operations and maintenance. In 1997, drying curing weed cityofficials relocated LBCGA’s garden to be adjacent to El Dorado Park, on 8.5 acres of land. LBCGA currently has a food bank which donates fresh produce to local charities, and its tree orchard “provides a visual and sound buffer between the gardens and the 605 Freeway” .Ban et al. and Tijerina both studied The Growing Experience, a joint collaboration between the Housing Authority of Los Angeles County and the University of California Cooperative Extension, which transformed a neglected lot into a community resource. Ban et al. , who studied the impact of a Community Service Agriculture program, found that The Growing Experience offered organic produce at a more affordable cost than supermarkets, and made a conscious effort to include ethnicallyappropriate crops targeted to the local primarily Latino and African-American populationof the Carmelitos Housing Project. CSA subscribers and Carmelitos residents who used The Growing Experience’s Farmer’s Market ate more fruits and vegetables than residents who did not participate in The Growing Experience. However, the CSA boxes were more expensive than the majority of non-organic produce from local supermarkets, so some residents were unwilling to participate due to financial and time restraints. One resident described that it was difficult to buy fresh produce then cook it after working all day .

The Carmelitos Housing Project was originally designed for low-income families, specifically serving soldiers who had just returned home from World War II. Unfortunately, Carmelitos became notorious for violence, drug, and gang culture . Tijerina , who focused on types of environmental justice offered by The Growing Experience, found that the area surrounding Carmelitos was a food desert located near 309 hazardous waste sites, 48 sites that released toxic chemicals, and 15 sites that reported air emissions to the Environmental Protection Agency. The Growing Experience resisted environmental injustices and aimed to uplift locals from poverty by offering a CSA program, farmer’s market, community garden, community kitchen, business and job training, and other educational and economic opportunities . However, nearly a decade after Ban et al. and Tijerina’s case studies were published, the Los Angeles County Development Authority nearly shut down The Growing Experience due to budget constraints. In 2021, they laid off all but one staff member . As of 2022, The Growing Experience is managed in partnership with the MAYE Center, a nonprofit that helps Cambodian residents cope with trauma from the Cambodian Genocide .This document listed a total of 22 UA sites, suggesting that attempts to map UA in Long Beach may be inconsistent. More recent sources from 2017 to 2023 indicate that there are potentially 66 UA sites in Long Beach, including 28 community gardens, and 30 public school garden sites, and 10 urban farms . Some UA sites are managed by one entity. For example, as of 2024, nine community gardens are managed by the nonprofit organization, Long Beach Organic . As of March 2024, the nonprofit Ground Education manages 24 school gardens in the Long Beach Unified School District . Additionally, Ground Education provides gardening activities to other UA sites, including Adventures to Dreams Enrichment, Farm Lot 59, and Sowing Seeds of Change . An undated webpage from the City of Long Beach claimed there are 30 LBUSD gardens. In a 2021 article from the local newspaper The Grunion, assistant public information director Evelyn Somoza reported that LBUSD has 20 district-approved gardens that receive mulch and weed pickup . Murray elaborated that while 20 school gardens completed the district’s application process, there may be additional self-maintained gardens. Information on Long Beach school gardens was limited to those within Long Beach Unified School District and did not include private or charter schools. In general, there is a lack of research on Long Beach school gardens . This dissertation will contribute to scholarly knowledge on gardens and urban farms in LongBeach, by investigating community engagement in UA through field observations and interviews.This study was guided by the social determinants of health framework and the community cultural wealth model, which relate to the dissertation’s focus on communities uniting to improve their health and environment through UA. UA can positively impact SDOH, which are socioeconomic and environmental factors that influence individual or community health . The Healthy People 2030 initiative, developed by the Office of Disease Prevention and Health Promotion of the U.S. Department of Health and Human Services, groups SDOH into five domains . These domains provide context for why health inequities occur, as well as how they can be addressed . By targeting SDOH, UA can potentially improve physical and mental health outcomes . For example, many studies reported that UA fosters social capital . Social capital is part of Yosso’s CCW model, which highlights communities’ cultural knowledge, skills, and abilities. Additionally, social capital connects to the “social and community context” domain of SDOH.In this section, I will disclose my background to provide context for qualitative data collection and analysis. Self-reflexivity is an important consideration of qualitative methods, as researchers’ experiences affect their interpretation of data.

Plaques, a zone of clearing on the bacterial lawn, were construed as evidence for the presence of phage. Overall, we found very little evidence for the presence of either lytic or lysogenic phages that attacked any of our bacterial isolates. We did find some evidence for lysogens: 20% of bacterial isolates showed evidence for the presence of lysogenic phages in the B only lines. There was evidence for lysogeny in only 7% of isolates in the BP lines where both types of phages were passaged. With regard to lytic phages in the original phage fraction, we also did not find evidence for phage predation of any bacterial isolate using this starting inoculum. The results are reported in Table 2.Overall, disruption of co-passaging of bacteria and phage on leaves over time and between plants was found to have an impact on both the composition and diversity of the resultant epiphytic bacterial communities. The bacterial communities resulting from passaging bacteria with their ancestral phage appeared to be the most dissimilar as compared to the other passaging treatments. This microbiome also had lower alpha diversity than that of both only bacteria passaged only and bacteria passaged along with any potentially evolving phage . BPa lines also have lower beta diversity than all other treatments, and Pseudomonaceae dominated the communities. All of this taken together suggests that the original phage present in the inoculum is capable of having the largest impact on the community, drying and curing buds even to a bacterial community that may have changed in composition by passaging on plants.

The most parsimonious explanation for this finding is that the phages present in the initial inoculum have low persistence in the phyllosphere, at least in a growth chamber, and as such, there were both more, and perhaps more diverse phage present in the initial inoculum than what remained after attrition on the leaf surface during passaging in the growth chamber. This is, however, not fully supported by our phage-isolation attempts, as we were unable to isolate phages from the original phage-fraction on any bacterial isolates. However, this may be explained by the apparent decay of phages during refrigeration as observed by others, and it does not preclude the possibility that there were lytic phages present at the time of the passaging experiments . In treatments in which lytic phages were passaged for three weeks, it is likely that the phage fraction contained very little, if any, active phage particles by the end of the experiment. This is supported by the fact that we were unable to recover any phage isolates from the final time point of the experiment, except for one isolate from plants exposed to a BPa microbiome. Poor persistence of phages in the phyllosphere is a finding supported also supported by the work of others. Phages, in general, are found in very low incidence on the surface of leaves compared to that in endophytic compartments. This may be due to phage’s sensitivity to UV on the surface of leaves, or may be due to low replication of bacteria in the phyllosphere, which is a nutrient-deplete environment that may limit bacterial growth, and hence lytic phage replication. The strong effect of the ancestral phage fraction on the bacterial community is consistent, in some regards, to the findings described in Chapter 4.

There, we found that after one week, plants that received bacteria and phage together had lower beta diversity than plants receiving only bacteria . Plants receiving passaged bacteria and ancestral phage have significantly lower beta diversity than both B and BP treatments. In both cases, it may be that the impact the original phage fraction had on the bacterial community shaped it in a way that made all the microbiomes similar to one another. Interestingly, alpha diversity was also the lowest in this treatment, yet there are no differences in alpha diversity between the B and BP treatments. The alpha diversity finding may be explained by the taxonomy of the bacteria that was most impacted by the phage fraction. Here, Pseudomonaceae was in highest relative abundance in the BPa treatment- the treatment with the lowest alpha diversity. In previous work, the Bacteria-only treatment had a significantly higher relative abundance of Pseudomonaceae as well. Again, this treatment had the lowest alpha diversity. Thus, it is possible that the phage fraction has an initial impact on a dominant bacterial family in the phyllosphere, and this lethality subsequently has a ripple effect on alpha diversity of the rest of the community. Future work using rationally designed synthetic communities of bacteria and phages could address with hypothesis with more clarity. One of the primary goals of this work was to disentangle the effects of lytic and lysogenic phages on bacterial communities in the phyllosphere. Through our experimental design, we attempted to include a variety of lytic versus lysogenic phage challenges to the bacteria. Visually, it appears that the bacterial communities in which only lysogenic phages were passaged are different from those in which lytic phages were passaged. Furthermore, 20% of bacterial isolates showed evidence for the presence of lysogenic phages in the B only lines in which only lysogenic phages were passaged.

In contrast, there was evidence for lysogeny in only 7% of isolates in the BP lines where both types of phages were passaged. However, these findings are not statistically significant, and thus no conclusions can be drawn. This work highlights the importance of time-scale when studying the effects of phages on the phyllosphere bacterial community. Predictions about alpha diversity based on results after only a one week experiment are not entirely consistent with our findings from the study of communities that were passaged between plants for three weeks. Specifically, we did not find an increase in alpha diversity in the lines in which both bacteria and phage were passaged together compared to bacteria-only lines. This may indicate that temperate phages are able to mediate long-term bacterial diversity as well as lytic phage, or it may be unrelated to the presence of phages and reflect other microbial dynamics occurring in the community. Future work that involves more rigorous identification of lysogenic phages, such as bacterial genome sequencing, may help address the question of their importance in maintaining diversity. We also found that the ancestral phage fraction has the strongest impact on both composition and diversity of the bacterial communities – probably because it was more abundant. Finally, our lack of ability to culture phages after passaging on plants suggests strongly that lytic phage particles do not persist well in the phyllosphere of plants grown in the growth chamber This supports work by others indicating that the feasibility of using phages as bio-control agents in agriculture may be largely dependent on their ability to persist in the phyllosphere. Overall, these findings are an important extension of previous work , and they underscore many of the unanswered questions that remain regarding the abundance, persistence, growing tray and importance of bacteriophages in the phyllosphere.A diverse field inoculum was generated using field-grown tomato plants. Above ground tomato plant material was collected from two fields from the UC Davis Student Organic Farm in June 2018. The material was stored on ice for transportation to the lab. One hundred grams of plant material was submerged in 1.5L of 10mM MgCl2 and sonicated for 5 minutes, vortexed for 30 seconds, and sonicated again. This was repeated with an additional 500 grams of plant material, 100 grams at a time. The leaf wash from above was filtered using 8 µm filter paper to remove large pieces of plant debris. The flow-through containing all microbes was then filtered using .22µm filter units. Microbes collected on the filters, which should be most bacteria, were sonicated off the filter paper into sterile buffer for 10 minutes. To concentrate the phage fraction of the microbiome, .22 µm flow-through was then concentrated using 100Kda MWCO Millipore filter units. Both the bacterial and phage fractions were split into 8 aliquots to account for the 3 weeks of inoculation and the need for ancestral phage and ancestral bacteria for weeks 2 and 3. Bacterial fractions were stored at -80°C in 1:1 KB glycerol, and phage fractions were stored in the dark at 4°C. On each day of inoculation, bacterial aliquots were re-suspended in 3mL of MgCl2 without the addition of any other fractions for the “B only” treatment. A bacterial aliquot was combined with a phage fraction aliquot for “B and P”. For the first week, three treatment groups received B and P. Inoculum was spray inoculated onto each plant individually. After 1 week, entire plants were harvested individually. Bacterial and phage fractions were recovered from the plants as described previously . The bacterial and phage fractions were re-combined and inoculated onto the plants. For evolved bacteria and ancestral phage, the bacterial fraction from the end of the passage was combined with an ancestral phage aliquot from frozen storage. For the ancestral bacteria and evolved phage treatment, the phage fraction from the end of the passage was combined with an aliquot of the ancestral bacterial treatment from frozen storage.

The experiment was continued for three passages in total, each consisting of one week.My thesis work began by demonstrating that vertically transmitted bacteria on the surface of tomato seeds are capable of protecting seedlings against a common bacterial pathogen. Vertical transmission is a well-studied process in other systems such as termites and aphids [192]. However in plants, it has been primarily limited to the transmission of pathogens and endophytes. Both are important fields of study- especially for the prevention of plant diseases. However, I felt that there was a significant lack of knowledge as to the functional importance of vertically transmitted commensals or mutualists in plants. Intuitively, vertical transmission of a microbiome or symbiont would allow for maintenance of key members of the microbial community across generations. Beneficial microbes would have primary access to both spatial niches and nutrients provided by seedlings. Interestingly, plants have a differential onset of resistance to pathogens throughout their life-stages, something described as age-related resistance or developmental resistance. However, much of the work on ARR investigates exposure and resistance to specific pathogens throughout the developmental stage of the plant and does not address if there is a crucial window of exposure to commensals, and whether these commensals ae contributing to ARR, as observed in other systems. To my knowledge, there are no studies to date that test the importance of timing of commensal microbial exposure on microbiome establishment or immune function in plants, although there is a wealth of literature on establishing biological control agents. For example, would a seedling exposed to beneficial microbes mount as strong of a response as an older plant? And would exposure of otherwise sterile adults result in the same successional dynamics of microbiome establishment as often observed in seedlings? Given that we know that resistance to pathogens can change throughout the life cycle of a plant, research focused on age-related tolerance and recruitment of commensals and plant-growth promoting bacteria has large implications in seed treatment and agricultural practices. One fundamental question that I was unable to answer is: are the types of bacteria transmitted on seeds merely a reflection of the parental plant from which the progeny was generated? If so, do transmitted microbes vary based on adult-plant microbiomes? If so, which anatomical portion of the plant is most influential in shaping the seed microbiome? In this workwe found that some seed microbiomes were more protective than others. This suggests that they may have differed in their composition, but we never confirmed that this was the case. Furthermore in my work on adult plants, I found that plant host genotype influences the phyllosphere microbiome. Are these differences between microbiomes heritable through vertical transmission? In order to address these outstanding questions, I would conduct a common garden experiment wherein multiple host genotypes would be planted in replicated field sites. Upon fruiting, I would not only collect tomato fruits, but I would also collect leaf, flower, and soil from each site. I would collect seeds from fruits using the same approach as described in Chapter 2. I would carry out Gyrase B amplicon sequencing in order to describe the bacterial communities of the seeds in addition to the adult plants from which they came.

The similarity of changes in community structure both across replicates and genotypes over the course of the passaging experiment led us to predict that these microbiomes were adapting to the local plant and greenhouse environment. To further determine if the community changes we observed from P1 to P4 were due to habitat selection rather than neutral processes, we employed a community coalescence competition experiment. In this experiment , phyllosphere communities from the end of P1 and the end of P4 were inoculated onto a new cohort of plants, either on their own or in an approximately 50:50 mixture of live cells . To ensure that our method for the mixed inoculum was effective, we sequenced multiple replicates of the P1, P4, and Mix inoculums and found that source of inoculum explains 88% of dissimilarity amongst samples . To ensure that the Mix inoculum was significantly different than both P1 and P4 separately, we compared P1 and Mix inocula directly and found that 75% of difference between samples can be explained by this variable . Similarly, when P4 and Mix are compared directly, 74% of variation in the community is explained . This consistent difference among the three inocula allowed us to compare the communities colonizing plants from each treatment. We first measured final bacterial abundance and found that colonization was lower on these plants than in previous experiments, pipp mobile storage systems but does not significantly differ among treatments , apart from control plants, where bacterial colonization was greatly reduced .

We then compared bacterial communities again using 16S amplicon sequencing and ordinated samples on a PCoA based on Bray-Curtis distances. Plants that received P1 inoculum had distinctly different communities than those that received either P4 or the Mixed inoculum. Plants that received the Mixed inoculum clustered together with those receiving P4 and were relatively indistinguishable. Using ADONIS tests, we determined that inoculum source can explain 45% of Bray-Curtis dissimilarity amongst samples , and there was no effect of plant genotype . In a pairwise analysis between P1 and Mixed, inoculum source explains 31% of the community dissimilarity . In contrast, inoculum source does not explain any significant variation in dissimilarity amongst P4 and Mixed inoculum plants . Together, these results suggest that the plants receiving the 50:50 mixed inoculum were indistinguishable in community composition from those receiving the pooled, P4 adapted microbiomes, and that these selected communities were not invadable by the microbial communities from the start of the experiment. Consistent with our results from the passaging experiment itself, alpha diversity was highest in P1 plants compared to both P4 and Mixed plants . Alpha diversity did not differ amongst communities colonizing plants from the P4 and Mixed inoculums, despite being different between the two inocula themselves. We also examined compositional makeup of the communities , and consistent with P1 to P4 passaging results, we see differentially abundant taxa between groups .

Again, two Pseudomonas OTUs are more abundant in P1 plants as compared to P4 and Mix, in which there was an unclassified Pseudomonaceae that was higher in relative abundance.The impact of a microbiome on host health and fitness depends not only on which microbial organisms are present in the community, but also on how they interact with one another within the microbiome. Unlocking the great potential of microbiome manipulation and pre/probiotic treatment in reshaping host health will therefore depend on our ability to understand and predict these interactions. We took a microbiome passaging approach, inspired by classic experimental evolution, to test how selection for growth in the tomato phyllosphere under greenhouse conditions would impact microbiome diversity and adaptation across genotypes that differ in disease resistance genes. Across independently selected lines passaged on five tomato genotypes, we observed a dramatic shift in community structure and composition, accompanied by a loss of alpha diversity . We also found that host genotype shapes community composition early in passaging , explaining over 24% of variation amongst samples, but diminishes over time. The relative importance of host genotype and environment in shaping microbiome composition remains highly debated. Our results suggest that the relative importance of genotype versus other factors, such as the growth environment or strength of within-microbiome interactions, changes over the course of passaging on a constant host background. We did observe that even in the absence of a strong genotype effect, there remains a legacy of genotype effect, in that OTUs found to be significantly associated with particular genotypes early on are more likely to be present at the end of passaging than those that did not exhibit any host preference.

In order to test if the phyllosphere microbiome undergoes habitat filtering, we chose to begin the experiment with a diverse inoculum. This starting community generated from field grown tomato plants likely contained microbes from other surrounding plant species, dust, soil, and other sources. In particular, neighboring plants have been shown to contribute to both the density and composition of local airborne microbes. We found that although the total number of these field inoculum OTUs decreased over the course of the experiment, the taxa that remained consistently made up 78-95% of the community. This provides evidence that the original spray inoculum underwent strong niche selection over the course of the experiment. To test the alternative hypothesis that community changes were due to neutral processes such as bottle necking or random dispersal, we first fit our data to neutral and null models, finding a poorer fit over time. We then tested this experimentally by conducting a community coalescence experiment to measure fitness of passaged microbiomes as compared to those from the start of the experiment. The results of this experiment strongly support the idea that these phyllosphere microbiomes adapted to the plant host environment over the course of four passages . Independent of overall bacterial abundance, P4 microbiomes were able to dramatically outcompete the less-adapted P1 microbiomes. This community coalescence approach allowed us to demonstrate non-neutral adaption of a bacterial community that is independent of host genotype and resistant to invasion by a more diverse, less-adapted community. This community coalescence approach was used by others in a study conducted on methanogenic bacterial communities. The authors found that when multiple methanogenic communities were combined, a single dominant community emerged from the mix. This emergent dominant community resembles the single community with the highest methane production that went into the combination, suggesting that the most-fit community is capable of reassembly, even in the presence of other bacteria.The impact of a microbiome on host health and fitness depends not only on which microbial organisms are present in the community, but also on how they interact with one another within the microbiome. Unlocking the great potential of microbiome manipulation and pre/probiotic treatment in reshaping host health will therefore depend on our ability to understand and predict these interactions. We took a microbiome passaging approach, cannabis growing systems inspired by classic experimental evolution, to test how selection for growth in the tomato phyllosphere under greenhouse conditions would impact microbiome diversity and adaptation across genotypes that differ in disease resistance genes. Across independently selected lines passaged on five tomato genotypes, we observed a dramatic shift in community structure and composition, accompanied by a loss of alpha diversity . We also found that host genotype shapes community composition early in passaging , explaining over 24% of variation amongst samples, but diminishes over time. The relative importance of host genotype and environment in shaping microbiome composition remains highly debated. Our results suggest that the relative importance of genotype versus other factors, such as the growth environment or strength of within-microbiome interactions, changes over the course of passaging on a constant host background. We did observe that even in the absence of a strong genotype effect, there remains a legacy of genotype effect, in that OTUs found to be significantly associated with particular genotypes early on are more likely to be present at the end of passaging than those that did not exhibit any host preference. In order to test if the phyllosphere microbiome undergoes habitat filtering, we chose to begin the experiment with a diverse inoculum. This starting community generated from field grown tomato plants likely contained microbes from other surrounding plant species, dust, soil, and other sources. In particular, neighboring plants have been shown to contribute to both the density and composition of local airborne microbes.

We found that although the total number of these field inoculum OTUs decreased over the course of the experiment, the taxa that remained consistently made up 78-95% of the community. This provides evidence that the original spray inoculum underwent strong niche selection over the course of the experiment. To test the alternative hypothesis that community changes were due to neutral processes such as bottle necking or random dispersal, we first fit our data to neutral and null models, finding a poorer fit over time. We then tested this experimentally by conducting a community coalescence experiment to measure fitness of passaged microbiomes as compared to those from the start of the experiment. The results of this experiment strongly support the idea that these phyllosphere microbiomes adapted to the plant host environment over the course of four passages . Independent of overall bacterial abundance, P4 microbiomes were able to dramatically outcompete the less-adapted P1 microbiomes. This community coalescence approach allowed us to demonstrate non-neutral adaption of a bacterial community that is independent of host genotype and resistant to invasion by a more diverse, less-adapted community. This community coalescence approach was used by others in a study conducted on methanogenic bacterial communities. The authors found that when multiple methanogenic communities were combined, a single dominant community emerged from the mix. This emergent dominant community resembles the single community with the highest methane production that went into the combination, suggesting that the most-fit community is capable of reassembly, even in the presence of other bacteria.Seeds were surface sterilized using TGRC recommendations as follows: seeds were soaked in 2.7% bleach solution for 20 minutes. Sterilized seeds were then transferred onto 1% water agar plates and placed in the dark at 21°C until emergence of the hypocotyl. At that point, seedling plates were moved into a growth chamber and allowed to continue germination for 1 week. Growth chamber conditions were 25°C, 65% humidity and 16 h daylight per day. After approximately one week, seedlings were transferred planted in sunshine mix #1 soil in seedling trays. After approximately one more week of growth, seedlings were transplanted into 8” diameter pots, making the plants approximately 2.5-3 weeks old at the first time of microbial inoculation. Age of inoculation varied slightly from experiment to experiment but was kept identical amongst genotypes within an experiment.Microbial inoculum for the first passage of the experiment was generated from field-grown tomato plants from the UC Davis Student Organic Farm collected in September and October of 2016. One-gallon Ziploc bags were filled with leaf, stem, and some flower material from tomato plants. One bag was collected from each of nine different sites, spread through four different fields. Plant material was collected from various genotypes of tomatoes. Other plant types, such as lettuce, eggplant, corn, and oak trees, surrounded the tomato fields. During the October collection, soil was also collected at each site. The top ~2cm of soil was brushed away, and a 50mL conical was pushed directly into the soil at the base of a plant which was in the middle of each collection site. Plant material and soil were transferred to the lab on ice and stored at 4°C briefly until processing. Sterile phosphate freezing buffer was added to the bags of leaves, and the entire bags were placed in a Branson M5800 sonicating water bath. Material was sonicated for 10 minutes. This gentle sonication washes microbes from the surfaces of the leaves but does not damage cells. The resulting leaf wash from each site was pooled. From the September collection, leaf wash was pelleted for 10 mins at 4000 x G, resuspended in glycerol freezing buffer, and stored at -80 for approximately one month. This was then thawed, re-spun to remove the freezing buffer, and combined with the October leaf wash.

The human immune system maintains a homeostatic relationship with commensals through numerous mechanisms, including stratification and compartmentalization of the intestine, production of a mucous layer and antimicrobial proteins, and limiting epithelial exposure and immune response. Two studies in Arabidopsis thaliana demonstrate that disrupting components of the plant immune system, such as the signaling molecules salicylic and jasmonic acid, influences microbial communication composition: the first shows evidence for altered root microbiome communities in plant hosts lacking genes controlling production of SA compared to control plants; and the second shows altered microbial communities in plants with mutations in genes controlling ethylene response and cuticle formation. Recent work in wheat also demonstrated a role for jasmonic acid in shaping composition of the microbiome, and again in this case, activation of JA signaling pathways altered microbial diversity and composition of root endophytes. In mammals, microbiota are critical in development and function of components of adaptive immunity, such as B and T cell diversity and differentiation. In plants, curing weed commensal bacteria influence host immunity by priming the plant for future exposure to pathogens through the induction of a systemic response, causing broad-range basal levels of protection.

A primed plant may respond more rapidly and strongly to pathogen invasion through a variety of mechanisms including: quicker closing of stomata, less sensitivity to bacterial manipulation of defenses, up regulation of defense-related genes, and stronger salicylic acid related immune responses. In some cases, the effects of priming can even be trans-generational through chromatin and histone modification, where the subsequent generation of primed plants exhibits enhanced resistance to bacterial, fungal, and herbivorous pathogens. Host-associated microbiota can also directly influence host resistance against invading pathogens. Common across most systems, the microbiome can serve a protective role that is independent of the host immune system through antagonism, competitive exclusion, or physical exclusion of pathogens, collectively referred to as defensive symbiosis. Recently, the phyllosphere microbiome, discussed in this work, has been found to protect its plant host against pathogens. In mammals it is clear that early exposure to microbes is crucial to the development of both branches of the immune system, influencing not only immune development and response against pathogens, but also tolerance to commensal microbiota. The role of early exposure to microbiota suggests it would be advantageous for a community of beneficial microbes to be transmitted vertically from parent to offspring from generation to generation. Transmission of microbiota in plants can occur vertically through the seeds, or horizontally from the soil and surrounding environment.

Plants ranging from trees to grasses are known to harbor bacteria in their seeds, many of which are reported to promote plant health. Despite this, there is no evidence that plants actively select for transmission of specific microbial communities, and there are no clear examples of adaptations to ensure seed mediated transmission. My work in Chapter 2 explores this topic through uncovering the importance of some seed-transmitted microbes in early seedling health.The plant phyllosphere is defined as the aerial surfaces of plants, or, all plant tissues growing above ground. This work primarily focuses on microbial epiphytes of the phyllosphere: the bacteria, viruses, and fungi that are found on the surfaces of leaves. The phyllosphere is a massive habitat estimated to exceed 108 km2 of plant surface area worldwide. It is, in general, a nutrient poor environment that undergoes fluctuations in temperature, UV, and moisture. The phyllosphere microbiome is known to harbor primarily four phyla of bacteria, and they reach an abundance of ~106 cells/cm2. Microbes from surrounding plant species, dust, soil, and other sources are thought to be the primary colonization source for the phyllosphere. In particular, neighboring plants have been shown to contribute to both the density and composition of local airborne microbes. However, as demonstrated in Chapter 3, the microbes frequently described as members of the phyllosphere microbiome may in fact be transient visitors and not well-adapted colonizers of the environment. Although there is a trend in phyllosphere research to focus on the bacterial portion of the microbiome, there have been some studies describing the fungal community as well.

There is even less work on the viral community, although from culture-based work, we know that bacteriophage viruses do indeed inhabit the phyllosphere and predate upon the bacterial community. There are many technical limitations that impede the field’s ability to fully describe the phyllosphere phage community. Nevertheless, my work in Chapters 4 and 5 contribute to our understanding of the importance of bacteriophages in this system. Compared to the field’s understanding of the below ground microbial habitat, the rhizosphere, the phyllosphere has been relatively understudied. Despite this, there are many advantages to the system. Specifically, the phyllosphere has a naturally distinct spatial structure, it is relatively easy to sample, and the microbes are highly culturable. Through inoculation using a fairly simple spray technique, the environment can be evenly saturated with diverse microbial inoculum, and it is possible to sample the successfully colonized community in its entirety. It is also easy to visualize, and spatial patterns of colonization and survival can be easily ascertained. Moreover, bacterial abundance and growth can be tracked using droplet digital PCR, and the bacterial and fungal communities can be described using next generation sequencing. Overall, the phyllosphere is an ideal system in which to study topics such as the relative importance of transmission events, host characteristics, the environment and microbemicrobe interactions in shaping the microbiome.Symbiotic associations between plants and microbes span from pathogenic to beneficial, and these interactions have been studied from many angles of science- from evolution to agriculture. My dissertation research seeks to address fundamental questions about microbial community ecology and host-microbiome interactions. It is motivated by the belief that rational design or manipulation of complex microbial communities has the potential to shape the future of medicine and agriculture, but this success will largely depend on our basic understanding of the systems at hand. Plant associated microbiomes are capable of enhancing host fitness through a number of mechanisms. They can promote growth through production of phytohormones and fixation of nutrients from the environment, confer both drought and stress tolerance, and even influence flowering time of their hosts. Perhaps one of the most influential ways that microbial organisms affect host fitness is through their impact on host immunity and disease resistance. In plants, microbes can confer disease resistance through both indirect and direct mechanisms and can indirectly protect against disease via the plant immune system. Plants are able to detect microbial-associated molecular patterns such as lipopolysaccharides in the environment, activating a generalized anti-microbial defense mechanism, and effectively priming the plant to respond more effectively when subsequently exposed to a pathogen. Experimental studies using isolated strains of bacteria have demonstrated that many can protect plants against pathogen colonization through direct inhibition of the pathogen’s growth, either through competition for resources or production of antimicrobials. Furthermore, there is long-standing understanding that plants can be ‘primed’ against pathogen colonization by colonization of non-pathogenic bacteria. It is now becoming clear that the microbiome as a whole might act collectively to confer disease resistance, although it is more difficult to pinpoint mechanisms underlying the effects of whole consortia compared to studying individual strains using culture-dependent methods. Both the rhizosphere and phyllosphere microbiomes have recently been shown to provide protection against pathogens. But even as we begin to understand microbiome-mediated protection against disease, it is unclear how a naturally protective community might assemble on a plant, and, once assembled, if it can be stably maintained over time. A broader consideration of how plant-associated microbiomes are acquired and transmitted among hosts is required to better understand how a generally beneficial community might persist across generations. The two dominant sources for assembly of the plant microbiome are horizontal transmission from the environment and unrelated plants and vertical transmission from parental plants. Local plant populations are important contributors to the airborne microorganism community, and thus that movement of microbes among neighboring plants can readily occur through aerial dispersal. Unlike horizontal transmission, however, cannabis protective tray vertical transmission holds the potential to connect, extend, and reinforce beneficial symbioses across temporal and spatial scales.

In plants, vertical transmission of microbial communities is observed in both vegetative and sexual reproduction. Parental microbiota can be transmitted through the foliar and vascular pathways onto seeds, though the most likely route across plant species remains unclear . Once on or within the seeds, they can act as the incipient members of a mature plant microbiome, critically shaping growth, development, and susceptibility to pathogens of newly emerging seedlings. Such transmission would allow plant lineages to maintain beneficial symbioses across multiple generations and pave the way for coevolution of the partners, as has been well-characterized in other systems . Moreover, studies on seed-associated microbes have focused primarily on endophytes from surface sterilized seeds, despite the fact that the seed surface is the most immediate interface between the embryo and parental tissues. As a result, endogenous seed epiphytes remain a relatively unexplored group, despite their potential importance in early colonization of plants. Here we present a study in which we examine whether endogenous seed epiphytic microbes, both as a community and in isolation, protect seedlings of various tomato types against a common plant pathogen, Pseudomonas syringae pv tomato strain DC3000 . By transferring naturally occurring seed-associated microbial communities back onto surface-sterilized seeds of either the original cultivar or different genotypes, and comparing pathogen colonization and disease susceptibility against un-inoculated control seedlings, we were able to test the impact of multiple seed-associated communities and bacterial isolates on disease progression, and examine the dose-dependence of protection conferred.Tomato fruits were collected from UC Davis Student Organic Farm in September 2017. We collected mature, intact fruits from a total of four different tomato types based on distinct fruit morphologies and field locations including: orange cherry tomatoes, red cherry tomatoes, medium-orange-sized tomatoes, and an unidentified heirloom variety. Fruit of the same tomato type/cultivar were collected from multiple plants planted in the same row, resulting in four tomato types . Tomato Type 1-3 were collected from non-neighboring lanes from one field, and the heirloom variety was collected from a neighboring field. Tomatoes were brought into the lab, pooled within tomato type , sterilized, and then fermented to collect seeds.Intrigued as to what made TT4 seed microbiota protective on not only its own tomato genotype but also others, we used 16S rRNA community profiling to sequence the bacterial communities of two week old seedlings whose seeds had been inoculated with TT4 microbiota. We found that these seedlings were strikingly dominated by OTUs in the genus Pantoea . Knowing that Pantoea is highly culturable, and also that many species are already used as biocontrol strains, we next sought to culture isolates from TT4 seeds to determine the exact species of Pantoea that were endogenously found on these seeds. We were able to culture six bacterial isolates from TT4 seeds. We also tried to culture bacterial isolates from the other three tomato types, and we were only able to culture one bacterial isolate from TT2, which we identified as a Bacillus species . Using Sanger sequencing, we sequenced the 16S genes of our isolates and identified them as species of Pantoea . Because Pantoea spp. are notoriously difficult to differentiate using 16S sequences, we chose three isolates based on distinct colony morphology and different 16S sequences, and sequenced their gyrB and rpoB genes as well. We were able to further confirm their identities and place them within a phylogenetic tree of Pantoea spp.. To our knowledge, our isolates have not been previously identified nor used as bio-control strains, although some related strains have been developed . Interestingly, ZM3 andZM2 appear to be similar based on DNA sequencing, with their partial 16S sequences aligning 99% to one another and their partial gyrB sequences aligning 100%. However, when grown on nutrient agar, their colonies are distinctly different colors; yellow and white, respectively. Whole genome sequences will further elucidate genetic differences between the isolates and are currently underway. Lastly, we aligned our ~420bp of amplicon sequencing data to near full length reverse Sanger sequencing reads of the isolates and observed 100% match of some of these OTUs with our isolate sequences .Through a combination of culture-dependent and independent methods, we were able to directly test the protective effects of naturally occurring seed-associated microbiota, both in consortia and as single isolates.

Similarly, according to Tena’s chronography, the summer solstice took place toward the end of the sixth month, called Etzalqualiztli. At that time, sunrise would have seemed to stand still at an azimuth of ca. 65°. Viewed from the top of the Templo Mayor, sunrise would have taken place behind Tepetlaoxtoc, in the western foothills of the Sierra de Patlachique, across the briny waters of Lake Texcoco where the Basin’s saltworks were . In coincidence, the first day of the seventh month, called Tecuilhuitontli, was devoted to a celebration in honor of Huixtocihuatl, the goddess of salt. Close to the summer solstice bearing, further east from the salty lakeshores, there were fertile agricultural terraces with cultivated milpas, or cornfields. Sahagún noted that in the eighth month, called Huey Tecuilhuitl, the goddess of fresh corn, Xilonen, or Chicomecoatl, was also celebrated. It does not seem coincidental that the name of Chiconcuac, a settlement found along this summer sunrise view, is derived from the name of this goddess. The winter solstice occurred close to the beginning of the 16th month, Atemoztli, a time in which sunrise seems to stand still at its southernmost azimuth of ca. 116°, on the northern slope of the Iztaccíhuatl volcano, the “sleeping woman” . According to Sahagún, the beginning of the following month, called Tititl, pipp mobile systems was devoted to celebrating Ilama Tecuhtli , also known as Tona .

The correlation between sunrise close to the woman-like volcano and the celebration of womanhood in general is striking. In summary, there seems to be a noteworthy association between some elements of the horizon calendar and the feasts and celebrations of each season: the arid spring equinox, when the sun rises behind Mount Tlaloc, was associated with Tlaloc, the god of water and rain. The summer solstice, when sunrise occurs behind the distant salty shores of Lake Texcoco, was associated with salt and summer corn. Finally, the winter equinox, when the sun rises at the side of Iztaccihuatl, the sleeping woman, was associated with womanhood and female gods.The previous analysis suggests a correlation between the Mexica calendar and the topographic elements of the Basin’s eastern horizon but leaves an important question unanswered, namely that of the calendric role of Mount Tlaloc. It seems very clear that the horizon calendar, as viewed from Tenochtitlan’s Templo Mayor, should have relied strongly on the date of the sun rising behind Mount Tlaloc, as this mountain could have provided, better than any other, the accuracy needed for the precise estimation of the length of the solar year and for leap year adjustments. However, none of the 16th century codices and manuscripts consulted for this study describe this phenomenon in a direct and clear manner, other than a general mention in Sahagún that at the beginning of the third month, close to the alignment date of sunrise with Mount Tlaloc, a feast was made to Tlaloc, the god of rains. If the alignment of sunrise with Mount Tlaloc was indeed an important calendric landmark when viewed from Templo Mayor, a clear mention could have been expected in the ancient codices, including the question of why did the Mexica not use the Mount Tlaloc alignment to mark the beginning of the new year.

The answer to this paradox may lie in the ruins of the ceremonial center found at Mount Tlaloc’s peak. The summit of Mount Tlaloc is crowned by a rectangular walled enclosure about 40 m east–west by 50 m north–south . This courtyard, or tetzacualo, consists of stone walls that have been estimated to have been 2 to 3 m high when originally built, with a ca. 94° east-west azimuth . The eastern side of the precinct opens to a 150 m-long, ca. 6 m-wide, walled straight causeway that has an azimuthal bearing of 101°55′, offset more than 8°southward from the roughly east–west bearing of the enclosure . Because the causeway runs down slope on the western side of the peak, some researchers have wondered whether the causeway was intentionally misaligned with the axis of the enclosure in order to accommodate a particular orientation to the setting sun . If viewed upslope, the azimuthal bearing of Mount Tlaloc’s causeway and the angular elevation of 4°02′ above the celestial horizon defines a point in the celestial sphere that aligns with the sun’s apparent position on February 23 to 24 each year. That is, an observer standing at the lower end of the causeway will see the rising sun appear in the center of the upper part of the stone ramp on February 23 or 24, after the last nemontemi day and in synchrony with the beginning of Basin’s new year as defined by Tena’s first chronology . The causeway seems to have been constructed as a calendric solar marker with a celestial bearing that allows for leap-year adjustments and indicates the end of the year and the beginning of a new solar year. The idea that the structure was used for precise astronomical observations is further reinforced by the fact that it seems to have had specific sight markers to avoid parallax error. Wicke and Horcasitas described that the causeway had a stone circle in its upper end where, presumably, a monolith could have stood. Correspondingly, it still has a stone square with an erect, 40-cm monolith in its lower end. Jointly, they could have been used as alignment markers to further improve alignment accuracy.

Almost a century ago, Rickards described the presence of a monolith with the figure of Tlaloc in the center of the tetzacualo and aligned with the causeway, as had been described earlier by Durán . Although the figure has been removed since , it could have functioned as yet another element for precise solar alignments . The importance of Mount Tlaloc as a solar observatory is enhanced by the fact that the two largest peaks of the Mexican Transversal Volcanic Axis east of the Basin of Mexico are visible from its peak and almost perfectly aligned. Viewed from the center of the stone courtyard, the nearest peak, Matlalcuéyetl or Malinche has an azimuth of 105°52.7′ while Citlaltépetl or Pico de Orizaba has an azimuth 105°26.5′. Because the azimuthal difference between the two peaks is less than the angular width of the sun’s disk, viewed at dawn they will seem like a single mountain with twoclose crests, where sunrise would be seen on February 10. In short, the causeway in Mount Tlaloc marks very precisely the beginning of the Mexica solar year, but the summit courtyard could have been used to identify a precise alignment 15 d before the beginning of the year, during Izcalli—the last month of the Mexica calendar. Ceramic fragments are common in and around the enclosure, and these fragments have been collected by archeologists and dated to the Mesoamerican Classical Period, early Toltec, and Mexica, suggesting that the site was used for ceremonies from the beginning of the Common Era to the collapse of the Mexica Empire in the 16th century . Although the constructions have not been dated with precision, early chroniclers reported that the sanctuary in Mount Tlaloc was used by the Toltecs before the 7th century CE and by the Chichimecs in the 12th century, before the arrival of the Aztecs to the Basin . It seems likely, then, industrial drying rack that the astronomical use and significance of the Mount Tlaloc causeway, and hence the beginning of the Mesoamerican calendar, preceded the founding of Tenochtitlan and the development of the Mexica civilization.Broda noted that the causeway of Mount Tlaloc points toward Mount Tepeyac, a hill that emerges from the Basin’s sediments south of the Sierra de Guadalupe, a range of basaltic mountains in the center of the Basin of Mexico. Indeed, when viewed from Tepeyac, Mount Tlaloc has an azimuth of 100°54′, very close to the bearing of the causeway on Tlaloc’s peak and an elevation of 2°38′ . Mount Tepeyac is the southernmost hill of the Sierra de Guadalupe, only 4 km northeast and 7 km east of the pre-Hispanic settlements of Tlatelolco and Azcapotzalco. According to Sahagún , the hill had been a place of worship and pilgrimage for the inhabitants of the Basin long before the Spanish Conquest. Broda’s observation suggests a visual alignment of calendric importance may have existed between the Tepeyac ranges and Mount Tlaloc. Indeed, sunrise alignment with Mount Tlaloc occurs on February 24 if viewed from Mount Tepeyac. Like the alignment in the summit’s causeway, the Mount Tepeyac solar alignment date corresponds with that of the causeway and also heralds the beginning of Tena’s new year . It can be hypothesized, then, that before the Mexica built the Templo Mayor, the inhabitants of the Basin of Mexico were using the alignment between Tepeyac and Mount Tlaloc as a fundamental landmark in their horizon calendar. They could have adjusted with precision their agricultural calendar to the solar year based on the sunrise alignment between Mount Tlaloc and Tepeyac.Agriculture was already well established in the Basin of Mexico by the first millennium BCE, largely around the Pre-classic Cuicuilco culture in the southwest of the Basin.

The Cuicuilco civilization collapsed in the 3rd century CE when the Xitle volcano became active and covered the whole south of the Basin under a mantle of lava . Broda has analyzed the horizon calendar as viewed from the main pyramid of Cuicuilco, built ca. 600 BCE, almost nine centuries before the apogee of the Mexica Empire. She concluded that the sunrise alignment with Mount Papayo on March 24, close to the equinox, “could have constituted a simple and effective mechanism to adjust for the true length of the solar year, which needed a correction of 1 d every 4 y.” Broda’s studies on Cuicuilco provide strong evidence suggesting that rigorous calendric calculations and leap-year adjustments wereat the heart of the development of Mesoamerican agricultural civilizations from very early times and were certainly very important in pre-Classical settlements. In addition to the equinoctial alignment of sunrise with Mount Papayo, the Cuicuilco observatory would have provided good calendric alignments with Mount Telapon and with the “head” of the “sleeping woman” profile of the Iztaccihuatl volcano . The latter date is very close to Tena’s estimate for the beginning of the Mexica calendric year and, because of Iztaccihuatl’s majestic proportions when viewed from the south of the Basin, could also have constituted an important landmark for calendric adjustments .Many early codices seem to validate the working hypothesis that Mount Tlaloc was instrumental in the establishment of the date of the Basin’s new year and in the adjustments necessary to keep the agricultural calendar in synchrony with the solar year. As discussed previously, Sahagún described how Atlcahualo, the first month of the year, was devoted to celebrate the Tlaloc gods of rain. Similarly, in Duran’s description of the nemontemi days, he reported that the year ended when a sign of the first day of the new year became visible above a mountain peak , suggesting the use of a landmark alignment to indicate the beginning of the new year. Similar associations between Mount Tlaloc and the first day of the new year are shown in other ancient codices, such as Codex Tovar, Codex Borbonicus, and the Wheel of Boban . The narrow historical relationship between the first month Atlcahualo and Mount Tlaloc has been recently described in detail by Broda . From an ecological perspective, it seems clear that the rugged eastern horizon of the Basin provided precise landmarks that would have allowed to adjust the xiuhpohualli, the count of the years, with the true solar calendar. Sahagún’s description of the feasts and ceremonies associated with some of the Mexica “months,” or 20-d periods, coincides well with themes from landmarks visible in the sunrise horizon from the Templo Mayor. Because of its position near the equinox, when viewed from the center of the Basin, Mount Tlaloc seems to have played a very important calendric role. The long causeway at the summit strongly suggests that the ceremonial structure was used as a solar landmark, aligning very precisely with the rising sun on February 23 to 24 and October 19 to 20. The same alignment is found if Mount Tlaloc is viewed from Mount Tepeyac, a holy site whose use as a sacred mount and solar observation post preceded the establishment of the Mexica civilization in the Basin.

By crops, we mean either annual or perennial crops, including tree crops. At the field scale, DFS may include polycultures, noncrop plantings such as insectary strips, integration of livestock or fish with crops , and/or rotation of crops or livestock over time, including cover cropping and rotational grazing. Around the field, DFS may incorporate noncrop plantings on field borders such as living fences and hedgerows. At the landscape scale, DFS may include natural or semi-natural communities of plants and animals within the cropped landscape/region, such as fallow fields, riparian buffers, pastures, meadows, woodlots, ponds, marshes, streams, rivers, and lakes, or combinations thereof . The resulting heterogeneous landscapes support both desired components of biodiversity and “associated biodiversity”; together these two elements make up agrobiodiversity . Components of the agrobiodiversity within DFS interact with one another and/or the physical environment to supply critical ecosystem services to the farming process, such as soil building, nitrogen fixation, nutrient cycling, water infiltration, pest or disease suppression, and pollination, pipp grow rack thereby achieving a more sustainable form of agriculture that relies primarily upon inputs generated and regenerated within the agroecosystem, rather than primarily on external, often nonrenewable, inputs .

Spatial considerations are important, since different components of the system must be in sufficient proximity, at each relevant scale, to create needed interactions and synergies. For example, the utility of intercropping for reducing below ground soil disease depends on spacing the different crops such that their root systems interact . Similarly, wild bee communities can only provide complete crop pollination services when a sufficient proportion of their natural habitat occurs within a given distance of crop fields . A DFS is not only spatially heterogeneous, but is variable across time, due both to human actions , and natural successional processes. Figure 1 presents the conceptual model of a DFS.The term agroecology goes back more than 80 years and originally referred to the ecological study of agricultural systems . Much agroecological work seeks to bring Western scientific knowledge into respectful dialogue with the local and indigenous knowledge that farmers use in managing ecological processes in existing agroecosystems . More recently this hybrid science has evolved to include the social and economic dimensions of food systems . Partly in response to the industrialized agriculture of the Green Revolution , agroecology also came to mean the adoption of sustainable agricultural practices , and became an integral component of various social movements seeking alternatives to industrial agri-food systems.

Thus agroecology currently holds multiple meanings, and can refer to an inter- or transdisciplinary science, a set of sustainable farming practices, and/or a social movement . DFS is not an alternative to agroecology. Rather, DFS is a framework that draws from agroecological, social, and conservation sciences to focus analytical and action-oriented attention toward farming systems in which cross-scale ecological diversification is a major mechanism for generating and regenerating ecosystem services and supplying critical inputs to farming. Agroecological principles and methods can be used to evaluate DFS and to design or revive processes of diversification . In this essay and series of articles, we explore the ramifications of DFS for both ecological health and socioeconomic welfare, as well as examining the intersection of DFS with existing industrialized agricultural systems, supply chains, and national and international policies.DFS are complex social-ecological systems that enable ecological diversification through the social institutions, practices, and governance processes that collectively manage food production and biodiversity . As many political ecology scholars emphasize, ecosystems are densely interconnected with social relationships . Ecological variables such as soil, water, and habitat help configure an array of farming practices, exchanges of food and resources, and landscape management decisions that, in turn, influence the structure and function of the ecosystem.

Further, as ecosystem services are generated and regenerated within a DFS, the resulting social benefits in turn support the maintenance of the DFS, enhancing its ability to provision these services sustainably . This interplay underlies numerous historically occurring and emerging DFS worldwide. Conversely, socio-political and economic processes such as the decrease of access and control over seeds or increased dependence on commodity markets can intervene to disrupt such feedback cycles, thus weakening DFS. The industrialization of agriculture has led to growing homogeneity across food systems as farming techniques and markets become more standardized . As a consequence, the complex social relationships underlying agriculture and ecosystem service provision have become less visible. Focusing on DFS can help farming communities, researchers, policy makers, and industry recognize and restore these relationships. At their core, DFS depend on agroecological principles that are developed in and through the social relationships among working farmers, their communities and environments, and researchers, including ecologists, anthropologists, agronomists, and ethnobiologists . As seen in the Kreman et al. examples these principles take varied forms depending on local conditions. To understand how DFS may develop, function, and evolve over time and space, the particular context of each DFS needs to be studied, paying particular attention to the politics and power relations that reciprocally shape its ecological conditions. Many DFS were developed through traditional and indigenous farming knowledge and agrobiodiversity that was accumulated over millennia . More recently, other DFS have been created through targeted agroecological studies designed by scientists to solve particular problems . Historically, much knowledge about biologically diverse farming practices has been created and shared through peer-to-peer learning within traditional farming communities and, more recently, also through their collaboration with researchers interested in further developing agroecology . These relationships continue to be critical to the growth of DFS in new societal contexts and geographic locations. Since the 1980s, with the rise of the Campesino-a-Campesino and La Via Campesina movements, institutions such as government agencies, domestic and international NGOs, and universities have become increasingly active in promoting and diffusing agroecological principles through research networks and programs . These actors have added new institutional dimensions to the social relationships that help sustain DFS. An illustration of how social and ecological systems interpenetrate within DFS is in the Andean highlands, where indigenous farmers have managed their lands agroecologically for 3,000 years . The ongoing interplay between human management and physical ecology has created a landscape of agroclimatic belts at different altitudes, each characterized by specific field rotation practices, terraces, and irrigation systems, and the selection of specific animals, crops, and crop varieties . Within these belts, traditional knowledge has helped sustain tremendous genetic diversity, by perpetuating adapted landraces and wild relatives of crops. Social cooperation is essential to managing the verticality and heterogeneity of the Andean ecosystem. A barter economy based on reciprocity, for example, facilitated complementary exchanges of plants and animals between ecological zones along the steep elevation gradient .In industrialized systems in both developed and developing countries, farmers must now negotiate with corporate food buyers, buy agrochemical and seed inputs from agents, seek loans from bank officials, and work with agricultural extension experts trained in pesticide use. Farmers rely on such relationships to compete effectively in supply chains and to manage changing ecological conditions, such as pest outbreaks. Nonetheless, these particular types of relationships often push individual farms to increased dependence on banks, damaging livelihoods, pipp horticulture racks cost and undermining collaborative social learning groups as farmers specialize in a single crop and maximize short-term yields through the use of external inputs, to meet loan repayments. The economic pressures in these tightly linked systems generally corrode ecosystem services, which are the very foundation of support for potential DFS. Farmers in industrialized systems may also engage in exploitative relations with immigrant or impoverished laborers, paying inadequate wages and enforcing long hours, helping perpetuate the apparent cheapness of food. Industrial production creates a number of “distances” between producers and consumers such that information flow diminishes across the supply chain . Thus within the industrial agri-food system, consumers remain relatively ignorant about the conditions of production, and would be less able to choose between products based on sustainability criteria, if they value these, and to exercise their buying power in favor of DFS.

In turn, the risk perceptions of consumers and corporations may inhibit the growth of DFS. For example, during the recent food safety scare in fresh leafy vegetables in California, corporate buyers insisted that growers remove native vegetation bordering fields that might attract wildlife. This action was taken largely to assuage consumer concerns, despite the lack of scientific support . In alternative agricultural systems such as organic or low-input farming, farmers can build particular forms of relationships that help sustain ecosystem services and social infrastructure more effectively. We discuss many of these relationships, including direct marketing, fair trade certification, and food justice movements. In developing and studying these alternative systems, however, researchers, policy makers, and NGOs often neglect race, socioeconomic, and gender issues, or sublimate them into a broad social justice category. Finding ways to be far more inclusive of diverse racial, gender, and socioeconomic groups can help strengthen the socialecological basis of agriculture. For instance, African-American growers once represented a sizable proportion of the U. S. farmer population, or one million in 1910, declining to 18,400 by 1997, due to race discrimination and violence, lack of land tenure , and multiple waves of economic migration from the South to urban centers . Many of these black farmers used DFS practices; their displacement helped create an opening for industrialized monocultures. Now, many new farmers in rural and urban areas are black, Latino, or Asian; there is evidence that these farmers are more likely than their established peers to embrace sustainable agriculture practices if adequately supported . Immigrants such as the Hmong may sometimes develop culturally relevant, more diversified food production enclaves within industrialized systems that preserve their traditions and provide livelihoods . They are developing new linkages between cities and nearby rural areas, potentially helping recreate DFS. For example, Will Allen founded Growing Power, an urban farming NGO that serves disadvantaged neighborhoods in Milwaukee and Chicago, attempting to encourage youth of all races to take up diversified farming. In Chicago, black activists and physicians have formed the Healthy Food Hub, a food aggregation NGO which sources produce from a historically black farming community, Pembroke Township, about an hour from Chicago. These efforts show how people can demand greater political agency in building a democratic DFS . New quantitative and qualitative research is badly needed to evaluate and critique the social benefits that DFS may provide in contrast to industrialized systems. In general, further analysis is needed to understand how the social elements of DFS can help generate and regenerate ecosystem services, thus maintaining diversified farming systems. In turn, more research is required on the political and socioeconomic interventions that could help rebuild or sustain the socialecological cycles that underlie DFS.DFS are often embedded in social, political, and economic conditions that differ from those accompanying industrialized monocultures , particularly with respect to core stakeholders, markets, and distribution systems. Yet, DFS may not always be able to realize their potential social-ecological benefits due to the lack of enabling environments. We explore how alternative agri-food networks and socialmovements relate to DFS and assess their potential to both maximize social benefits and promote DFS through their demands for food sovereignty and food justice. The agri-food systems approach reveals the interconnected systems of inputs, labor, land, capital, governance and knowledge that maintain specific types of agricultural production, distribution, and consumption systems . The governance and structure of the food system upstream from the farm, such as international agricultural trade liberalization policies that promote cheap food imports from industrial into developing countries, government subsidies for fossil fuel-based agrochemicals and commodity crops and irrigation projects that primarily benefit larger landholders , all help to maintain the industrialized agri-food system . This system then creates substantial obstacles to farmers seeking to use diversified farming methods, generate value from ecosystem services, and sell food products to viable markets. It also leaves consumers and communities disconnected from the origins, qualities, and the social and ecological consequences of the production of their food, fuel, and fiber. In the same way that industrialized monoculture production systems are sustained by industrialized agri-food systems, diversified farming systems are frequently interdependent with alternative agri-food networks .

This research would be incomplete without a description of the presence of spousalrun dairy farms in the U.S. A spousal-run dairy refers to a dairy that is managed by two operators that are married to one another. There is a historic assumption that many dairy farms are run by spouses, however, this research finds that trends in spousal commercial dairy operations does differ greatly by state . For some states, like Wisconsin, New York, and Idaho, a significantly large share of commercial dairy farms was being run by spouses, with over 40% of commercial dairy farms in each state being spousal run. In California, 31% of commercial dairy farms are run by spouses, but New Mexico had relatively few commercial dairies run by spouses and a decrease from 15% to 13% from 2012 to 2017. A large share of female core operators of commercial dairies was married to a principal operator in 2012 and 2017 . In 2017 Texas had the largest share with 80% of female core operators married to a principal operator and then Idaho and Wisconsin both had more than 75%. New Mexico had the smallest share of female core operators married to a principal operator with 48%, but that remains a significant share. Next, flood and drain hydroponics age of commercial dairy operators has been a point of discussion for because of the increasing age of dairy farm operators. Table 5.9 presents the share of operators by gender and age group for the Census year and state.

Across all state the largest share of female operators was in the less than 50 years old age group with all states following a similar trend of a decreasing share of younger operators and increase in the share of older operators. For male operators the largest share was the less than 50 age group also had the largest share. There was a significant share of male operators in the larger age group categories across all states with every state, but Wisconsin, have at least 10% of operators being male and over the age of 66. Finally, previous literature suggested that women may be more likely to adopt sustainable-minded practices. Regarding organic production, this seems to be true. In 2017, most organic commercial dairies have at least one female core operator, except in New Mexico for which only 17% of organic commercial dairies have at least one female core operator . The share of organic commercial dairies with at least one female operator is larger than the overall share of commercial dairies with at least one female operator. There was an increase in the share of female core operators that operated an organic commercial from 2007 to 2017 , but this was also with the addition of the fourth operator. There has been a slight increase in the share of organic commercial dairies across all states, but in 2017 all states had less than 15% of commercial dairies with organic production .

Organic dairies do tend to have smaller herd sizes, in general and more milk sales revenue per cow. Organic commercial dairies have a larger share of female core operators than commercial dairies overall for all states, except New Mexico. In 2017, organic commercial dairies report at least a 30% or more share of female core operators, except New Mexico which only had an 8% share of female core operators . In every state, except New York, there was an increase in the share of female core operators that manage organic commercial dairy. The share of female core operators that manage an organic dairy decreased by 28% in New York but increased by 66% in Idaho.Next, I turn to explore the relationship between the farm size and gender demographics of farm operators and spousal-run operation. COA is panel data, meaning that it is both times series and cross sectional in nature. For my analysis, I utilize a log-linear model with fixed effects in order account for cross-state and cross-time differences. The farm size variables, of the individual farm at time , are the logged dependent variables including Cowsit number of milk cows , TMDit total sales revenue from dairy or milk, and TVPit total value of production. I utilize farm-level operator characteristics variables including a binary variable for the presence of a female core operator , the share female operator on the individual farm , and a binary variable that indicates a spousal run farm variable .

Furthermore, I included a variable to control for a relationship between the age demographics of operators on farm size. MaxAgeit describes the maximum age listed by any given core operator on an individual commercial dairy. Table 5.13 shows the list of variables use in regressions and their corresponding definition. In addition, αi and λt represent the state fixed effect and the time fixed effect, respectively, and uit is an error term. Xit represents a vector of farm operator characteristics and farm management characteristics. logFarmSizeit represents a vector of the logged farm size variables listed above.Equations 1 is the regression equation used to show the relationship between the presence of a female operator and farm size, accounting for age, state, and year influences on farm size. Table 5.14 shows the relative coefficients and standard errors of each regression. Concerning the number of milk cows, the presence of at least one female core operator relates to a decrease in the herd size by about 12.9%, when holding constant for age, state, and year influences on farm size. With herd size, when accounting for the presence of a female operator, the max age corresponds to an increase in the herd size by 0.5%. The presence of at least one female core operator suggests a decrease of the total value of production by 31% and all milk or dairy sales by about 13.4% as well. So, across all farm size measures, there are relatively similar results.A one-year increase of the maximum age of any core operator relates to an increase in the total value of production by about 0.7%.A water well is a hole, shaft, or excavation used for the purpose of extracting ground water from the subsurface. Water may flow to the surface naturally after excavation of the hole or shaft. Such a well is known as a flowing artesian well. More commonly, water must be pumped out of the well. Most wells are vertical shafts, but they may also be horizontal or at an inclined angle. Horizontal wells are commonly used in bank filtration, where surface water is extracted via recharge through river bed sediments into horizontal wells located underneath or next to a stream. The oldest known wells, Qanats, are hand-dug horizontal shafts extending into the mountains of the old Persian empire in present-day Iran. Some wells are used for purposes other than obtaining ground water. Oil and gas wells are examples of this. Monitoring wells for groundwater levels and groundwater quality are other examples. Still other purposes include the investigation of subsurface conditions, shallow drainage, artificial recharge, indoor vertical farming and waste disposal. In this publication we focus on vertical water-production wells commonly used to supply water for domestic, municipal, and agricultural uses in California. Our purpose is to provide readers with some basic information about water wells to help them understand principles of effective well construction when they work with a professional driller, consultant, or well servicing agency for well drilling and maintenance.The location of a well is mainly determined by the well’s purpose. For drinking and irrigation water-production wells, groundwater quality and long-term groundwater supply are the most important considerations. The hydrogeological assessment to determine whether and where to locate a well should always be done by a knowledgeable driller or professional consultant. The water quality criteria to use for drinking water wells are the applicable local or state drinking water quality standards. For irrigation wells, the primary chemical parameters of concern are salinity and boron and the sodium-adsorption ratio. Enough ground water must be available to meet the pumping requirements of the wells.

For large municipal and agricultural production wells, pumping rate requirements range from about 500 to 4,000 gallons per minute . Small- and medium-sized community water systems may depend on water wells that produce from 100 to 500 gpm. Individual homes’ domestic wells may meet their needs with as few as 1 to 5 gpm, depending on local regulations. To determine whether the desired amount of ground water is available at a particular location and whether it is of appropriate quality, drillers and groundwater consultants rely on their prior knowledge of the local groundwater system, experience in similar areas, and a diverse array of information such as land surface topography, local vegetation, rock fracturing , local geology, groundwater chemistry, information on thickness, depth, and permeability of local aquifers from existing wells, groundwater levels, satellite or aerial photographs, and geophysical measurements. In most cases, the well location is further limited by property ownership, the need to keep surface transportation of the pumped ground water to a minimum, and access restrictions for the drilling equipment. When locating a well, one should also consider the proximity of potential sources of contamination such as fuel or chemical storage areas, nearby streams, sewer lines, and leach fields or septic tanks. The presence of a significant barrier between such potential sources and the well itself is very important for the protection of the well.Once the well location has been determined, a preliminary well design is completed. For many large production wells, a test hole will be drilled before well drilling to obtain more detailed information about the depth of water-producing zones, confining beds, well production capabilities, water levels, and groundwater quality. The final design is subject to site-specific observations made in the test hole or during the well drilling. The overall objective of the design is to create a structurally stable, long-lasting, efficient well that has enough space to house pumps or other extraction devices, allows ground water to move effortlessly and sediment-free from the aquifer into the well at the desired volume and quality, and prevents bacterial growth and material decay in the well . A well consists of a bottom sump, well screen, and well casing surrounded by a gravel pack and appropriate surface and borehole seals . Water enters the well through perforations or openings in the well screen. The latter is necessary when a well taps multiple aquifer zones, to ensure that screened zones match the aquifer zones from which water will be drawn. In alluvial aquifers, which commonly contain alternating sequences of coarse material and fine material, the latter construction method is much more likely to provide clean, sediment-free water and is more energy efficient than the installation of a continuous screen. Hardrock wells, on the other hand, are constructed very differently. Often, the borehole of a hardrock well will stand open and will not need to be screened or cased unless the hard rock crumbles easily.The purpose of the screen is to keep sand and gravel from the gravel pack out of the well while providing ample water flow to enter the casing. The screen should also be designed to allow the well to be properly developed . Slotted, louvered, and bridge-slotted screens and continuous wire wrap screens are the most common types. Slotted screens provide poor open area. They are not well suited for proper well development and maintenance, and are therefore not recommended. Wire wrap screens or pipe-based wire wrap screens give the best performance. The additional cost of wire wrap screens can be offset if you only install screen sections in the most productive formations along the borehole. The purposes of the blank well casing between and above the well screens are to prevent fine and very fine formation particles from entering the well, to provide an open pathway from the aquifer to the surface, to provide a proper housing for the pump, and to protect the pumped ground water from interaction with shallower ground water that may be of lower quality. The annular space between the well screen, well casing, and borehole wall is filled with gravel or coarse sand . The gravel pack prevents sand and fine sand particles from moving from the aquifer formation into the well. The gravel pack does not exclude fine silt and clay particles; where those occur in a formation it is best to use blank casing sections.

Although dairy farm size can be characterized for the U.S. overall, there are important distinctions by state, as the dairy farm size distributions differ greatly by state. It is important to distinguish growth patterns of dairy farms by state. Macdonald et al. detail that larger dairy farms are able to capture economies of scale, more so than smaller dairies, resulting in a lower average milk production cost. However, the article does go on to specify that the distribution of dairy farm size differs greatly by state based on the specific financial and economic environment of the dairy industry in that state. Alternatively, some dairy farms lower the average milk production costs by capturing the economies of scope, i.e., diversification of sales. This could be characterized as raising and selling replacement dairy heifers, or other agricultural products such as grain to maintain economic viability. Finally, I consider the relationship that farm operator characteristics may have with farm size and the decision of a farm to exit. In Chapter Five, I detail a specific line of analysis related to the influence of female farm operators on farm size, flood drain tray but in this chapter, I will discuss the influence that the age of the farm operator may have on the farm size.

Dairy farm size changes in response to these and other factors is important in considering future trends in farm size and their impact on milk production in the U.S. and the future structure of the dairy industry. This chapter aims to characterize the herd size distributions of the U.S. dairy industry, present evidence on the characteristics of the farm size distributions, and then finally discuss the correlation between farm level characteristics and farm size. This chapter will be structured as follows: a brief overview of previous literature on firm and farm size, a discussion about farm size distribution estimation, and then the results and discussion.Economic research and discussion have produced several theories on firm size and firm growth to characterize industries and the economy. This section will briefly review important studies related to firm size more generally and then will move on to research specific to the study of farm size and the economics of dairy farm size and size distributions. The study of firm size by economists can be best discussed chronologically, as much of the research builds off one another or finds results inconsistent with previously held theories. In 1931, Gibrat postulated what has come to be known as Gibrat’s Law that a firm’s growth rate is independent of its size.

This would mean that the growth rate of an individual firm over a particular time period should not be influenced by its original size. Ijiri et al. , using the foundation built by Gibrat’s Law, finds that firms that grew over 10% in the subsequent period are more likely to see above industry average growth, due to continued benefits of innovation that occurred in the subsequent periods. Viner theorizes that firm size distribution is based on the industry environment and that individual firms have a U-shaped average cost curve and will function at the minimum of this curve. He goes on to specify that firm entries and exits are determined by the quantity demanded by the market. Lucas used these previous works to build a new theory about the size distribution of firms in an industry that looks at size distribution as a solution for output maximization with a given set of production factors and managers with varied human capital levels. This model predicts the size distribution of firms based on the managerial ability of laborers and then subsequent resource allocation. Jovanovic finds that smaller firms will tend to have higher growth rates than larger firms, but that these smaller firms are more likely to exit the industry than the larger firms.

Evans discusses growth relative to a firms age, finding that a firm’s growth can be tied to the age of the firm itself and that older firms have a slower growth rate. This theory is hypothesized to remain true for dairy farms. Stemming from foundation of Gibrat’s law, which claims that the firm size distribution follows a log normal distribution, there has been significant literature on the size distribution of firms that looks at fitting parametric distributions to actual firm size data. Kondo, Lewis, and Stella evaluate recent non-farm panel data from the U.S. Census Bureau and find that the current U.S. firm size data best fits with a log normal distribution, but there are differences in goodness of fit by industry. Akhundjanov and Toda use the original data, in Gibrat’s original paper, find that a Pareto distribution better characterizes the empirical size distributions. The distribution of firm size remains a fundamental part of research firm growth patterns and the literature on firm size has been directly applied to research on the growth rate of farms and farm size changes in different agricultural industries. Two common parametric distribution used in farm size distribution analysis are log normal and exponential. Allanson evaluates farm size trends in England and Wales finding that the log normal distribution fits farm size measures relatively well across time. WhereasBoxely uses an exponential distribution to evaluate farm size data from the Agricultural Census and finds that from 1935-1964 farm size shifted to the right, but that at the state level farm size does tend to follow the exponential distribution with some regularity. Before going any further in the analysis, it is important to outline the concept of farm size for this analysis. Farm size measures across the whole agricultural industry tend to leave out key details that give better and more accurate accounts of the size of the farm for the commodity/industry. For example, when looking at the size of U.S. farms overall measuring the size of the farm based on acreage will lead to inaccurate or confusing results. The acreage needed to generate the same revenue for corn versus dairy milk or strawberries is substantially different. However, looking at the dairy industry specifically, many different characteristics shape a dairy’s economic footprint on the market, and therefore, defining how to characterize dairy farm size is fundamental to discussing changes in the dairy market. One can characterize the size of a dairy by the number of milk cows, or herd size, as one measure of dairy firm size. However, other characteristics such as the quantity of milk produced, the value of production, and value-added on the farm could also be considered as farm size measures . Different farm size measures allow us to answer different agricultural economic questions. While analyzing the dairy industry it is relevant to consider herd size, the milk and/or dairy sale revenue of the firm, and the total value of production, as we have already discussed in Chapter 2. Previous research on dairy farm size documents strong trends toward consolidation in the U.S. with a decrease of about 50% of all registered U.S. dairies from 2002 to 2019 . These trends in consolidation have differed by location with historically dairy producing regions seeing a large share of exits, these states were historically made up of smaller and mid-size dairies. MacDonald et al. detail the cost differences between larger and smaller dairies with cost advantages for larger dairies that drive the investment decision to increase herd size. This research suggested that there would continue to be a steady decline in the number of smaller and mid-size dairies and that the trend of consolidation would likely continue. This trend has raised research questions about what factors influence the distribution of farm size and the decisions of some farms to exit the industry. A common, albeit incorrect, assumption about the size distribution of the U.S. dairy industry is that it is bimodal.

This assumption comes from news reporting and political commentary that there is a “declining” middle of farms in the U.S. and that there is this dichotomy between small, sometimes organic, flood and drain tray farms and larger farms. Again, Wolf and Sumner find no evidence of a bimodal dairy industry using Farm Cost and Return Surveys of dairy farms for the years 1989 and 1993. In MacDonald et al. , they suggest that larger dairies tend to have lower costs per cow, which allows them to capture greater economies of scale. The cost-minimizing efforts of individual dairy farms will influence the specific farm management choices that the farm makes, as only the individual farm has a true sense of where it sits on its long-run average cost curve. Some of these management decisions include the dairy’s strategy to capture economies of scope, through sales diversification, or vertically integrate to minimize input and production costs. Sumner and Wolf find that vertical integration has little influence on the farm size and that the tendency for farms in the Pacific and South to have larger herd sizes remains true, even when accounting for the levels of vertical integration. The farm’s choice to incorporate different management strategies reflects the incentives and constraints that the farm faces, i.e., influences of geographic location and capital. Other influences on management choices by dairies are in part due to different environmental regulations in each state that impact the average cost of production for dairy farms.There has been a significant amount of agricultural economic research on dairy farm size with respect to their risk management and technical efficiency. Tauer finds that smaller dairies in New York do have a high average cost of production than dairies with larger herd sizes, but that these higher costs are due to inefficiencies and efficient small dairies are competitive with the larger dairies. Tauer and Mishra examine whether differences in technology or efficiency characterize the higher cost that smaller dairy farms face and find that using a frontier cost of production analysis show that inefficiencies in smaller dairies characterize the higher costs, not technological differences. Zimmermann and Heckelei utilize a Markov Chain Model on dairies in the European Union to characterize farm size change and find that regional characteristics such as off-farm opportunities and unemployment rates are significant in relation to dairy farm size change. They also find that high milk prices slow down farm size change due to high milk prices correlation to uncertainty and price volatility leading to a decrease in investment. Wolf details how dairy farms in Michigan have increased their use of risk management tools from 1999 to 2011 and find that the use of such risk management tools was positively correlated with measures of dairy farm size. This research also discusses how age related to risk management adoption with younger dairy farmers being less likely to utilize the risk management tools. Wolf outlines characteristics of dairy farm size change across time Beyond management decisions influencing or being correlated with the farm size and farms’ decision to exit, previous economic literature has hypothesized about the possible influences of operator characteristics, like human capital , the number of female operators, the age of operators, or other farm operator characteristics on farm size. Sumner and Leiby find that human capital positively influences the size of the farm, and this is hypothesized to be due to increasing opportunity costs for dairy farmers with high levels of human capital. Dairy farmers that have the possibility of making more money elsewhere will do so, therefore it seems likely that dairy farms with sufficient returns, which tend to be found on larger dairy farms, will attract high human capital management. Another aspect of the previous research related to farm size and the dairy industry is farm exits. There have been several studies of individual farm movement across farm size groups and characterization of exits. Most of this literature, however, has been limited to regions or states. Macdonald et al. finds that in 2016 about 40 percent of dairy farms with at least 2,000 milk cows did not have positive net returns and that the share of dairies that did not have positive net returns increased as herd size decreased. However, they do note that negative returns in the dairy industry are seen as temporary lows by dairy operators, so they do not serve as a direct indication of an expected exit from the industry. Other reasons for exits from agriculture, or dairy specifically, include increased suburbanization of previously agricultural land, driving land prices up, and strong local economies, opening off-farm employment opportunities for farm operators.

The wind turbine stands on a tubular steel tower, with a base diameter of 1.9 m. The drive train generator operates at 1200 rpm, while the rotor spins at a nominal speed of 55 rpm. The Micon 65/13M wind turbine was used for the Long-Term Inflow and Structural Testing program at the USDA-ARS test facility in Bushland, Texas. This project was initiated by Sandia National Laboratories in 2001 to explore the use of carbon fiber in wind turbine blades. The wind turbine is equipped with CX-100 blades, those structural model used in current FSI simulations was validated in Section 3.4.1. FSI simulations of the full Micon 65/13M wind turbine are carried out at realistic operational condition. A constant inflow wind speed of 10.5 m/s and fixed rotor speed of 55 rpm are prescribed. These correspond to the operating conditions reported for the field tests in [84]. The air density and viscosity are 1.23 kg/m3 and 1.78×10−5 kg/, respectively. Zero traction boundary conditions are prescribed at the outflow and nopenetration boundary conditions are prescribed at the top, bottom, and side surfaces of the outer computational domain. No-slip boundary conditions are prescribed at the rotor, nacelle, and tower, and are imposed weakly. Figure 4.3 shows the computational domain and Figure 4.4 mesh used in this study. The mesh consists of 5,134,916 linear elements, grow racks which are triangular prisms in the rotor boundary layers and tetrahedra everywhere else in the domain. The mesh is refined in the rotor and tower regions for better flow resolution near the wind turbine.

The size of the first element in the wall-normal direction is 0.002 m, and 15 layers of prismatic elements were generated with a growth ratio of 1.2. Figure 4.4 shows a 2D blade cross-section at 70% span wise station to illustrate the boundary-layer mesh used in the computations. The computations were carried out in a parallel computing environment. The mesh is partitioned into subdomains using METIS, and each subdomain is assigned to a compute core. The parallel implementation of the methodology may be found in [95]. The fluid and structural equations are integrated in time using the Generalized-α method with the time-step size of 3.0 × 10−5 s for all cases. In each time step, block-iterative FSI coupling is employed, which is efficient and stable for the application considered here.In Figure 4.5 the time history of the aerodynamic torque is plotted. As can be seen from the plot, using FSI, we capture the high frequency oscillations caused by the bending and torsional motions of the blades. In the case of the rigid blade the only high frequency oscillations in the torque curve are due to the trailing-edge turbulence. For the rigid blade case the effect of the tower on the aerodynamic torque is more pronounced, while in the case of FSI it is not as visible due to the relatively high torque oscillations. The ’dips’ in the aerodynamic torque can be seen at 60◦ , 180◦ , and 300◦ azimuthal angle, which is precisely when one of the three blades is passing the tower. The computed values of the aerodynamic torque are plotted together with field test results from. The upper and lower dashed lines indicate the aerodynamic torque bounds, while the middle dashed line gives its average value. Both the aerodynamic and FSI results compare very well with the experimental data.We present a preliminary, ongoing FSI simulation of a 5MW offshore wind turbine undergoing yawing motion. The wind turbine is equipped with 61 m blades designed by Sandia.

The structural model of a blade used in current FSI simulations was validated in Section 3.4.2. The wind turbine rotor is positioned at 80 m above ground and is tilted by 5◦ to avoid the blade hitting the tower as the rotor spins. Furthermore, the wind turbine rotor plane is initially placed at 15◦ relative to the wind direction. A fixed yawing rotational speed is applied to the gearbox to slowly turn the rotor into the wind at 0.03 rad/s . The inflow wind speed is set to 11.4 m/s. The initial rotor speed is set to 12.1 rpm, and the rotor is allowed to spin freely during the prescribed yawing motion. The structural mechanics mesh of the full turbine has 13,273 quadratic NURBS shell elements and two quadratic NURBS beam elements. The aerodynamics mesh has a total of 5,458,185 linear elements. Triangular prisms are employed in the blade boundary layers, and tetrahedral elements are used elsewhere in the aerodynamics domain.The size of the first boundary-layer element in the wall-normal direction is 1 cm, and the time step of 0.0001 s is employed in the computation. Snapshots of the structure deformed configuration are shown in Figure 4.10, while isosurfaces of vorticity colored by flow speed are shown in Figure 4.11. Figures 4.12 and 4.13 show the time history of the axial component of the aerodynamic torque and angular speed. Both are slowly increasing as the rotor turns into the wind, as expected. The level of the computed aerodynamic torque is consistent with the earlier simulationsfor this wind turbine operating under similar wind- and rotor-speed conditions .We present an FSI simulation of a 1.2 kW VAWT, which is a three-bladed, medium-solidity Darrieus turbine designed by Windspire Energy. The details of wind turbine geometry together with aerodynamic validation using a field-test data are presented in Section 2.3.2. The structural model is presented in Figure 4.14.

The rotor and struts are made of aluminum, and the tower is made of steel. Quadratic NURBS are employed for both the beam and shell discretizations. The total number of beam elements is 116, and total number of shell elements is 7,029. As a part of FSI simulations, we perform a preliminary investigation of the startup issues in VAWTs using the FSI methodology described earlier and the structural model of the Windspire design. We fix the inflow wind speed at 11.4 m/s, and consider three initial rotor speeds: 0 rad/s, 4 rad/s and 12 rad/s. Of interest is the transient response of the system. In particular, we will focus on how the rotor angular speed responds to the prescribed initial conditions, and what is the range of the tower tipdisplacement during the VAWT operation. The VAWT is allowed to spin freely and accelerate under the action of the ambient wind. The time step in the computations is set to 2.0 × 10−5 s. The mesh moving technique described in Section 4.2 is applied to this case in a straightforward fashion. The radius and height of the inner cylindrical domain that encloses the rotor are 1.6 m and 7 m, respectively. That is, the cylindrical domain extends 0.5 m above and below the rotor blades. The rotor axis direction nrot is defined according to Eq. , where the points xori and xtip are located at the bottom and top intersections of the tower beam and shell, respectively. The instantaneous rotor angular velocity is computed from Eq. , the spinning component is removed as per Eq. , and the two angular velocities are used to update the sliding-interface mesh positions. We fluid mesh was adopted from the aerodynamics simulations presented in Section 2.3.2 The time history of rotor speed is shown in Figures 4.15–4.17. For the 0 rad/s case the rotor speed begins to increase suggesting this configuration is favorable for self-starting. For the 4 rad/s case, grow table the rotor speed has a nearly linear acceleration region followed by a plateau region. In [16] the plateau region is defined as the regime when the turbine operates at nearly constant rotational speed. From the angular position of the blades in Figure 4.16 it is evident that the plateau region occurs approximately every 120◦ when one of the blades is in a stalled position. It lasts until the blade clears the stalled region, and the lift forces are sufficiently high for the rotational speed to start increasing again. As the rotational speed increases, the angular velocity is starting to exhibit local unsteady behavior in the plateau region. While the overall growth of the angular velocity for the 4 rad/s case is promising for the VAWT to self start, the situation is different for the 12 rad/s case . Here the rotor speed has little dependence on the angular position and stays nearly constant, close to its initial value. It is not likely that the rotor speed will reach to the operational levels in these conditions without an applied external torque, or a sudden change in wind speed,which is consistent with the findings of [17]. Figure 4.18 shows, for a full turbine, a snapshot of vorticity colored by flow speed for the 4 rad/s case. Figure 4.19 zooms on the rotor and shows several flow vorticity snapshots during the rotation cycle.

The figures indicate the complexity of the underlying flow phenomena and the associated computational challenges. Note the presence of quasi-2D vortex tubes that are created due to massive flow separation, and that quickly disintegrate and turn into fine-grained 3D turbulence further downstream. Figure 4.20 shows the turbine current configuration at two time instances during the cycle for the 4 rad/s case. The displacement is mostly in the direction of the wind, however, lateral tower displacements are also observed as a result of the rotor spinning motion. The displacement amplitude is around 0.10-0.12 m, which we find reasonable given the tower height of 9 m, and one of the VAWT design objectives being that the structure is not too flexible. This is also the case for the 0 rad/s and 12 rad/s cases.In this dissertation more advanced FSI simulations of wind turbines, such as rotor yawing for HAWTs, and full-machine FSI of VAWTs were targeted. A structural model of wind turbines design was constructed and discretized using the recently proposed isogeometric rotation-free shell and beam formulations. This approach presents a good combination of accuracy due to the structural geometry representation using smooth, higher-order functions, and efficiency due to the fact that only displacement degrees of freedom are employed in the formulation. By constructing a detailed material model of wind turbine blade with non-symmetric, multilayer layup we were able to reproduce the experimentally measured eigenfrequencies of the CX-100 blade of Micon 65/13M HAWT. To our knowledge, this is the first full-scale validation of the IGA-based thin-shell composite formulation. The ALE-VMS technique for aerodynamics modeling was augmented with an improved version of the sliding interface formulation, which allows the interface to move in space as a rigid object and accommodate the global turbine deflections in addition to the rotor spinning motion. The pure aerodynamics computation produced good agreement with reported wind tunnel and field-test data. A simulation of two side-by side wind turbines was also performed. Using novel mesh moving techniques we were able to simulate a large scale 5MW HAWT undergoing yawing motion. We also present FSI simulations of full-scale Micon 65/13M wind turbine with the CX-100 blades mounted on its rotor. The results of the aerodynamic and FSI simulations shows a good agreement with field test data for this wind turbine. The FSI simulation captures high-frequency oscillations in the aerodynamic torque, which are caused by the blade structural response. In the future work we plan to explore methods and devices to mitigate such high-frequency rotor vibrations. Dynamic FSI modeling of VAWTs in 3D and at full scale were reported for the first time in this dissertation with investigation of turbine start-up issues. From the FSI computations we see that for given wind conditions the rotor naturally accelerates at lower values of angular speed. However, as the angular speed grows, the rotor may encounter a dead band region. That is, the turbine self-starts, but then it is trapped in a lower rotational speed than is required for optimal performance, and some additional input is required to get the rotor to accelerate further. There may be multiple dead band regions that the turbine needs to overcome, with external forcing applied, before it reaches the target rotational speed. In the future, to address some of these issues, we plan to couple our FSI formulation with an appropriate control strategy to simulate more realistic VAWT operation scenarios. The numerical examples presented in this dissertation illustrate the successful application of the proposed techniques to the FSI simulation of wind turbines at full scale.It has been reported that bacteria loads associated with enormous amount of animal waste produced in the U.S. are the leading cause of impairment for rivers and streams.