Center for Diversified Farming Systems Publications

Below is a partial list of recent publications by CDFS researchers.


Baur, P., Getz, C. & Sowerwine, J. Agric Hum Values (2017). doi:10.1007/s10460-017-9772-1

In an intensifying climate of scrutiny over food safety, the food industry is turning to “food safety culture” as a one-size-fits-all solution to protect both consumers and companies. This strategy focuses on changing employee behavior from farm to fork to fit a universal model of bureaucratic control; the goal is system-wide cultural transformation in the name of combatting foodborne illness. Through grounded fieldwork centered on the case of a regional wholesale produce market in California, we examine the consequences of this bureaucratization of food safety power on the everyday routines and lived experiences of people working to grow, pack, and deliver fresh produce. We find that despite rhetoric promising a rational and universal answer to food safety, fear and frustration over pervasive uncertainty and legal threats can produce cynicism, distrust, and fragmentation among agrifood actors. Furthermore, under the cover of its public health mission to prevent foodborne illness, food safety culture exerts a new moral economy that sorts companies and employees into categories of ‘good’ and ‘bad’ according to an abstracted calculation of ‘riskiness’ along a scale from safe to dangerous. We raise the concern that ‘safety’ is usurping other deeply held values and excluding cultural forms and experiential knowledges associated with long-standing food-ways. The long-term danger, we conclude, is that this uniform and myopic response to real risks of foodborne illness will not lead to a holistically healthy or sustainable agrifood system, but rather perpetuate a spiraling cycle of crisis and reform that carries a very real human toll. Download PDF here.

Nancy Lee Peluso (2017) Whigs and hunters: the origins of the Black Act, by E.P. Thompson, The Journal of Peasant Studies, 44:1, 309-321, DOI: 10.1080/03066150.2016.1264581

Edward P. Thompson was a British cultural historian, scholar of agrarian change and documenter of the complex, transformative class struggles of eighteenth-century England. His second major book, Whigs and hunters: the origins of the Black Act, was published in 1975, more than a decade after the huge success of his first book, The making of the English working class (Thompson 1963). In Whigs and hunters, Thompson demonstrates the myriad ways that the forests and ‘chases’ (hunting grounds) of southeastern England became key sites of massive legal, environmental, and social transformation and contention at this early moment in the nation’s history of capitalist social relations. In the 41 years since its publication, the book has attracted a veritable ‘cult’ of scholarly admirers among political ecologists and other researchers of agrarian-environmental change,1 drawn to it in part by the perpetuation of similar conflicts over land and resource control in our own times – with all the world as their stage. Download PDF here. 


Carlisle, Liz. The Terrace Keepers. Stanford Social Innovation Review. Stanford University, 2016. 13-14.

Excerpt: Upon entering the home of Clara Aboli, a visitor first notices the aroma. Aboli, a 33-yearold farmer and mother of four, beckons the visitor into her kitchen. She has prepared several dishes, but the visitor is drawn by the aroma that wafts from a steaming cauldron of red rice. Aboli and her family harvested the rice from the terraced fields that lie just above her house, which is located in the Cordillera mountains, a region of the Philippines. Aboli heaps a nutty mixture of three rice varieties—Jekot, Ulikan, and Unoy—onto the visitor’s plate. She smiles as she answers a few questions about the rice. In the past few years, she’s grown accustomed to people treating this humble mountain staple as a delicacy. On her farm, she grows two rice crops per year. “The first one we eat, and the second one is for Eighth Wonder,” she says. Eighth Wonder is a fair trade company that buys the heirloom rice grown by farmers like Aboli. “I try to do what I can to earn a little money for my kids,” says Aboli. “What if they want to go to school?” The income that she gains from selling her crop to Eighth Wonder helps her answer that question. Download PDF here.

Ponisio, L., and Ehrlich, P. “Diversification, Yield and a New Agricultural Revolution: Problems and Prospects.” Sustainability 2016, 8(11), 1118; doi: 10.3390/su8111118

The sustainability of society hinges on the future of agriculture. Though alternatives to unsustainable, high-input industrial agriculture are available, agricultural systems have been slow to transition to them. Much of the resistance to adopting alternative techniques stems from the perceived costs of alternative agriculture, mainly in terms of yields. The general assumption is that agriculture that is less harmful to people and wildlife directly will be indirectly more harmful because of yield losses that lead to food shortages in the short-term and agricultural extensification in the long-term. Though the yield gap between industrial and alternative forms of agriculture is often discussed, does industrial agriculture actually produce the highest yields? In addition, to what aspects of the food system is yield relevant? We review the evidence for differences in crop yields between industrial and alternative systems and then evaluate the contribution of yields in determining whether people are fed, the land in production, and practices farmers will adopt. In both organic and conservation agriculture, different combinations of crops, climate and diversification practices outperformed industrial agriculture, and thus we find little evidence that high input systems always outperform alternative forms of agriculture. Yield, however, is largely irrelevant to determining whether people are fed or the amount of land in production. A focus on increasing yields alone to feed the world or protect biodiversity will achieve neither goal. To promote sustainable agriculture, we must move past focusing on these oversimplified relationships to disentangling the complex social and ecological factors, and determine how to provide adequate nutrition for people while protecting biodiversity. View full article here.

Baur, P., Driscoll, L., Gennet, S., and Karp, D. “Inconsistent food safety pressures complicate environmental conservation for California produce growers. California Agriculture.” California Agriculture, 70(3):142-151. August 2016. DOI: 10.3733/ca.2016a0006.

Controlling human pathogens on fresh vegetables, fruits and nuts is imperative for California growers. A range of rules and guidelines have been developed since 2006, when a widespread outbreak of E. coliO157:H7 was linked to bagged spinach grown in California. Growers face pressure from industry and government sources to adopt specific control measures on their farms, resulting in a complex, shifting set of demands, some of which conflict with environmental stewardship. We surveyed 588 California produce growers about on-farm practices related to food safety and conservation. Nearly all respondents considered both food safety and environmental protection to be important responsibilities for their farms. Responses indicate that clearing vegetation to create buffers around cropped fields, removing vegetation from ditches and ponds, and using poison bait and wildlife fences are commonly used practices intended to reduce wildlife movements onto farm fields. The survey also revealed that on-farm practices vary substantially even among farms with similar characteristics. This variability suggests inconsistencies in food safety requirements, auditors’ interpretations or growers’ perception of the demands of their buyers. Although site-specific considerations are important and practices should be tailored to local conditions, our findings suggest growers, natural resources and food safety would benefit from clearer, more consistent requirements. Download here.

Montenegro de Wit, M., Iles, A. “Toward thick legitimacy: Creating a web of legitimacy for agroecology.” Elem Sci Anth 4: 000115. 2016. doi: 10.12952/journal.elementa.000115

Legitimacy is at the heart of knowledge politics surrounding agriculture and food. When people accept industrial food practices as credible and authoritative, they are consenting to their use and existence. With their thick legitimacy, industrial food systems paralyze the growth of alternative agricultures, including agroecology. Questions of how alternative agricultures can attain their own thick legitimacy in order to compete with, and displace, that of industrial food have not yet attracted much scrutiny. We show that both agroecological and scientific legitimacy grow out of a web of legitimation processes in the scientific, policy, political, legal, practice, and civic arenas. Crucially, legitimation often comes through meeting what we call ‘credibility tests’. Agroecologists can learn to navigate these co-constituted, multiple bases of legitimacy by paying attention to how credibility tests are currently being set in each arena, and beginning to recalibrate these tests to open more room for agroecology. Using a schematic of three non-exclusive pathways, we explore some possible practical interventions that agroecologists and other advocates of alternative agricultures could take. These pathways include: leveraging, while also reshaping, the existing standards and practices of science; extending influence into policy, legal, practical, and civic arenas; and centering attention on the ethical legitimacy of food systems. We conclude that agroecologists can benefit from considering how to build legitimacy for their work. Download PDF here. Read accompanying piece from Ensia here.

Maywa Montenegro de Wit. “Stealing into the wild: conservation science, plant breeding and the makings of new seed enclosures.” The Journal of Peasant Studies. June 2016. DOI: 10.1080/03066150.2016.1168405

Abstract: Field edge habitat in homogeneous agricultural landscapes can serve multiple purposes including enhanced biodiversity, water quality protection, and habitat for beneficial insects, such as native bees and natural enemies. Despite this ecosystem service value, adoption of field border plantings, such as hedgerows, on largescale mono-cropped farms is minimal. With profits primarily driving agricultural production, a major challenge affecting hedgerow plantings is linked to establishment costs and the lack of clear economic benefits on the restoration investment. Our study documented that hedgerows are economically viable to growers by enhancing beneficial insects and natural pest control and pollination on farms. With pest control alone, our model shows that it would take 16 yr to break even from insecticide savings on the US$4,000 cost of a typical 300-m hedgerow field edge planting. By adding in pollination benefits by native bees, where honey bees (Apis mellifera L.) may be limiting, the return time is reduced to 7 yr. USDA cost share programs allow for a quicker return on a hedgerow investment. Our study shows that over time, small-scale restoration can be profitable, helping to overcome the barrier of cost associated with field edge habitat restoration on farms. Download PDF here.

Calo, A., & De Master, K. T.  “After the incubator: Factors impeding land access along the path from farmworker to proprietor.” Journal of Agriculture, Food Systems, and Community Development. Advance online publication. March 2016.

Abstract: Farmworkers aiming to transition to independent proprietorship often benefit from beginning farmer incubator programs that offer agricultural training, subsidized farmland rents, and marketing and business assistance. Yet even as these promising initiatives provide former farmworkers with initial tools for success, structural barriers can impede beginning farmers’ eventual transition to independent proprietorship. Land access is one well-known barrier to entry. Impediments to land access for beginning farmers are frequently framed purely in terms of available acreage and/or sufficient start-up capital. Sociocultural and relational factors mediating land access are less well understood. Our study addresses this gap, examining how sociocultural and relational constraints impede land access for former immigrant farmworkers aspiring to independent farming in California’s Central Coast region. We employ qualitative methods, including 26 in-depth interviews, focus groups, and participant observation, to explore barriers to land access faced by aspiring small-scale organic farmers participating in an established regional organic farm incubator program. Our findings indicate that these beginning farmers are highly motivated, possess sophisticated farming skills, and wish to shape their livelihoods independently. However, their access to farmland is mediated by landowner and tenant farmer relationships, including lease arrangements, and sociocultural barriers, including ethnicity and/or cultural identity. Download PDF here.

Ponisio, L., M’Gonigle, L., Kremen, C. “On-farm habitat restoration counters biotic homogenization in intensively managed agriculture.” Global Change Biology. Volume 22, Issue 2, February 2016. DOI: 10.1111/gcb.13117.

Abstract: To slow the rate of global species loss, it is imperative to understand how to restore and maintain native biodiversity in agricultural landscapes. Currently, agriculture is associated with lower spatial heterogeneity and turnover in community composition (β-diversity). While some techniques are known to enhance α-diversity, it is unclear whether habitat restoration can re-establish β-diversity. Using a long-term pollinator dataset, comprising ∼9,800 specimens collected from the intensively managed agricultural landscape of the Central Valley of California, we show that on-farm habitat restoration in the form of native plant ‘hedgerows’, when replicated across a landscape, can boost β-diversity by approximately 14% relative to unrestored field margins, to levels similar to some natural communities. Hedgerows restore β-diversity by promoting the assembly of phenotypically diverse communities. Intensively managed agriculture imposes a strong ecological filter that negatively affects several important dimensions of community trait diversity, distribution, and uniqueness. However, by helping to restore phenotypically diverse pollinator communities, small-scale restorations such as hedgerows provide a valuable tool for conserving biodiversity and promoting ecosystem services. Download PDF here.

Montenegro de Wit, M. “Banking on Wild Relatives to Feed the World.” Gastronomica: The Journal of Food Sudies. Volume 16, Number 1, pgs. 1–8. 2016. DOI: 10.1525/GFC.2016.16.1.1.

Abstract: Crop wild relatives, the progenitors and kin of domesticated crop species, promise breeders a potent weapon against climate change. Having evolved outside the pampered environs of farms, wild relatives tend to be more rugged to survive temperature, salt, floods, and drought—all the extremes characteristic of a warming planet. But who will benefit from re-wilded crops? What kinds of agricultural systems will they tend to support? And can wild relatives be protected before they are lost under pavement, desertification, and expanding industrial farms? In this essay, I explore different visions of conservation and use for crop wild relatives. With CWR valued at an estimated $115–120 billion to the global economy annually, many researchers suggest ancient germplasm can be harnessed to feed billions in a warming world. Others look more closely at ancient customs and farmer knowledge that have long promoted conservation of wild species within and around cultivated landscapes. By intentionally planting crops at field borders, farmers also perform “in vivo” breeding. I conclude that wild relatives hold much potential to reinfuse diversity into eroded crop gene pools, providing greater systemic resilience. But unless we consider who controls seeds, intellectual property, and wild and agricultural lands, CWR innovations will only prop up an agriculture that ultimately undercuts crop and wild relative renewal. Download PDF here.


Carlisle, L. “Making Heritage: The Case of Black Beluga Agriculture on the Northern Great Plains.” Annals of the Association of American Geographers. Published online: 27 Oct 2015. DOI: 10.1080/00045608.2015.1086629

Abstract: This article considers the perils and potential of an increasingly popular alternative food commodity: heritage and heirloom foods. Drawing on ethnographic research with Black Beluga lentil farmers in Montana, I develop a process-based means of conceptualizing heritage agriculture, to avoid the pitfalls of simply reifying old crop varieties. This article makes three contributions to scholarship on alternative food commodities: (1) modeling a method of generative critique of alternative food movements that are in danger of being undermined by their articulation as commodity markets, (2) demonstrating how feminist ethnography of situated knowledge production can provide insight into processes of cross-species learning through which alternative food systems are created and sustained, and (3) suggesting that a reflexive approach to alternative food movement praxis is the best means of fostering environmental sustainability and social justice. Download PDF here.

DeLonge, M., Miles, A., and Carlisle, L. “Investing in the transition to sustainable agriculture.” Environmental Science and Policy. Volume 55, Part 1, January 2016. DOI: 10.1016/j.envsci.2015.09.013

Abstract: Ecological impacts of industrial agriculture include significant greenhouse gas emissions, loss of biodiversity, widespread pollution by fertilizers and pesticides, soil loss and degradation, declining pollinators, and human health risks, among many others. A rapidly growing body of scientific research, however, suggests that farming systems designed and managed according to ecological principles can meet the food needs of society while addressing these pressing environmental and social issues. The promise of such systems implies an urgent need for increasing the scope and scale of this area of research – agroecology. Notably, agroecological systems have been shown to reduce input dependency and therefore related research is unlikely to be supported by the private sector. Yet, the amount of federal funding available for agroecology has remained unclear. To address this gap in knowledge, we identified projects beginning in 2014 from the USDA Current Research Information System (CRIS) database and searched key sections of project reports for major components emphasizing sustainable agriculture, including agroecology. Components were grouped into four levels according to their focus on: improving system efficiency to reduce the use of inputs (L1), substituting more sustainable inputs and practices into farming systems (L2), redesigning systems based on ecological principles (L3: agroecology), or reestablishing connections between producers and consumers to support a socio-ecological transformation of the food system (L4: social dimensions of agroecology). We identified 824 projects, which accounted for $294 million dollars: just over 10% of the entire 2014 USDA Research, Extension, and Economics (REE) budget. Using a highly conservative classification protocol, we found that the primary focus of many projects was unrelated to sustainable agriculture at any level, but the majority of projects had at least one relevant component (representing 52–69% of analyzed funds, depending on whether projects focused exclusively on increasing yields were included). Of the total $294 million of analyzed funds, 18–36% went to projects that included a L1 component. Projects including components in L2, L3, or L4 received just 24%, 15%, and 14% of analyzed funds, respectively. Systems-based projects that included both agroecological farming practices (L3) and support for socioeconomic sustainability (L4) were particularly poorly funded (4%), as were L3 projects that included complex rotations (3%), spatially diversified farms (3%), rotational or regenerative grazing (1%), integrated crop-livestock systems (1%), or agroforestry (<1%). We estimated that projects with an emphasis on agroecology, indicated by those with a minimum or overall level of L3, represented 5–10% of analyzed funds (equivalent to only 0.6–1.5% of the 2014 REE budget). Results indicate that increased funding is urgently needed for REE, especially for systems-based research in biologically diversified farming and ranching systems. Download PDF here.

Carlisle, L.  “Audits and agrarianism: The moral economy of an alternative food network.” Elementa: Science of the Anthropocene (3). DOI: 10.12952/journal.elementa.000066

Abstract: With consumers and producers seeking alternatives to corporate, industrial food, systems of provision that promise greater ecological and social sustainability have gained in popularity. As these Alternative Food Networks (AFNs) scale up and go mainstream, both scholars and the general public want to know who is holding them accountable to their purported goals. In response to such questions, previously informal designations – such as organic – have become formalized, standardized, and institutionalized, and new certifications and business models promise improved traceability and transparency. I suggest, however, that successful alternative food networks – those that deliver on their promises of social and ecological sustainability – may be governed primarily by broad-based moral economies and support networks, and only secondarily by specific certification schemes or value chain quality control. Drawing on ethnographic research with a values-based supply chain on the northern Great Plains, I find that what creates incentives for sustainable practices and holds farmers accountable is less the regulatory component of certification or contractual stipulations of the value chain than the peer review aspect of belonging to the self-organized community that participates in these initiatives. While the organic certification process and values-based supply chain provide vehicles through which the moral economy of sustainable agriculture can operate, the moral economy itself precedes the notion of organic standards, dating back three generations to early twentieth century wheat pools. Since community formation and standard formation are achieved in very different ways, these findings have significant implications for policies aimed at encouraging transitions to more sustainable agricultural practices. Read full article here.

Figueroa, M. “Food Sovereignty in Everyday Life: Toward a People-centered Approach to Food Systems.” Globalizations. Special Issue: Food Sovereignty: Concept, Practice and Social Movements. Volume 12, Issue 4, 2015. DOI: 10.1080/14747731.2015.1005966

Abstract: This paper proposes a theoretical approach that de-centers ‘food’ in food-related research, placing social life as the point of departure for a critical analysis of food systems and the search for alternatives. Using a relational conception of food as a nexus of multiple, intersecting social-historical processes, a ‘people-centered’ approach illuminates the social elements that can inform resonant and locally inflected strategies for food sovereignty, particularly for urban communities in the USA. Building on theoretical concepts of primitive accumulation, articulation, and everyday life, as well as empirical work with the Chicago-based Healthy Food Hub, this paper explores the relationship between everyday food practices and historical processes of proletarianization as they are produced, reproduced, and contested at multiple conjunctures. In these spaces of contestation, the capacity for diverse communities to re-articulate social relations through everyday food practices could provide a potentially powerful pathway not just to food sovereignty, but an alternative to life under capitalism. Download PDF here.

Iles, A. and Montenegro de Wit, M. “Sovereignty at What Scale? An Inquiry into Multiple Dimensions of Food Sovereignty.” Globalizations. Special Issue: Food Sovereignty: Concept, Practice and Social Movements. Volume 12, Issue 4, 2015. DOI: 10.1080/14747731.2014.957587

Abstract: Food sovereignty has struggled to make inroads into changing the structures and processes underlying the corporate food regime. One reason is that scale is still underspecified in the politics, strategies, and theories of food sovereignty. We suggest that much can be learned from examining the multiple dimensions of scale inherent in ongoing food sovereignty struggles. A gap exists between these in vivo experiments and the maturing academic theory of scale. The concept of ‘sovereignty’ can be opened up to reveal that movements, peoples, and communities, for example, are creating multiple sovereignties and are exercising sovereignty in more relational ways. Relational scale can aid movements and scholars to map and evaluate how spatial and temporal processes at and among various levels work to reinforce dominant agri-food systems but could also be reconfigured to support progressive alternatives. Finally, we apply relational scale to suggest practical strategies for realizing food sovereignty, using examples from the Potato Park in the Peruvian Andes. Download PDF here.

Karp, D., Gennet, S., Kilonzoc C., Partykac, M., Chaumontd, N., Atwillc, E., and Kremen, C. “Comanaging fresh produce for nature conservation and food safety.” Proceedings of the National Academy of Sciences. Article first published online: 10 August, 2015. DOI: 10.1073/pnas.1508435112

In 2006, a deadly Escherichia coli O157:H7 outbreak in bagged spinach was traced to California’s Central Coast region, where >70% of the salad vegetables sold in the United States are produced. Although no definitive cause for the outbreak could be determined, wildlife was implicated as a disease vector. Growers were subsequently pressured to minimize the intrusion of wildlife onto their farm fields by removing surrounding noncrop vegetation. How vegetation removal actually affects foodborne pathogens remains unknown, however. We combined a fine-scale land use map with three datasets comprising ∼250,000 enterohemorrhagic E. coli (EHEC), generic E. coli, and Salmonella tests in produce, irrigation water, and rodents to quantify whether seminatural vegetation surrounding farmland is associated with foodborne pathogen prevalence in California’s Central Coast region. We found that EHEC in fresh produce increased by more than an order of magnitude from 2007 to 2013, despite extensive vegetation clearing at farm field margins. Furthermore, although EHEC prevalence in produce was highest on farms near areas suitable for livestock grazing, we found no evidence of increased EHEC, generic E. coli, or Salmonella near nongrazed, seminatural areas. Rather, pathogen prevalence increased the most on farms where noncrop vegetation was removed, calling into question reforms that promote vegetation removal to improve food safety. These results suggest a path forward for comanaging fresh produce farms for food safety and environmental quality, as federal food safety reforms spread across ∼4.5 M acres of US farmland. Download PDF here.

Karp, D.S., Baur, P., Atwill, E.R., De Master, K., Gennet, S., Iles, A., Nelson, J.L., Sciligo, A.R., Kremen, C. “The Unintended Ecological and Social Impacts of Food Safety Regulations in California’s Central Coast Region.” BioScience 65. 2015. DOI: 10.1093/biosci/biv152

Abstract: In 2006, a multistate Escherichia coli O157:H7 outbreak linked to spinach grown in California’s Central Coast region caused public concerns, catalyzing far-reaching reforms in vegetable production. Industry and government pressured growers to adopt costly new measures to improve food safety, many of which targeted wildlife as a disease vector. In response, many growers fenced fields, lined field edges with wildlife traps and poison, and removed remaining adjacent habitat. Although the efficacy of these and other practices for mitigating pathogen risk have not been thoroughly evaluated, their widespread adoption has substantial consequences for rural livelihoods, biodiversity, and ecological processes. Today, as federal regulators are poised to set mandatory standards for on-farm food safety throughout the United States, major gaps persist in understanding the relationships between farming systems and food safety. Addressing food-safety knowledge gaps and developing effective farming practices are crucial for co-managing agriculture for food production, conservation, and human health. Download PDF here.

Kremen, C. “Reframing the land-sparing/land-sharing debate for biodiversity conservation.” Annals of the New York Academy of Sciences. Article first published online: 27 July, 2015. DOI: 10.1111/nyas.12845

Abstract: Conservation biologists are devoting an increasing amount of energy to debating whether land sparing (high- yielding agriculture on a small land footprint) or land sharing (low-yielding,wildlife-friendly agriculture on a larger land footprint) will promote better outcomes for local and global biodiversity. In turn, concerns are mounting about how to feed the world, given increasing demands for food. In this review, I evaluate the land-sparing/land- sharing framework—does the framework stimulate research and policy that can reconcile agricultural land use with biodiversity conservation, or is a revised framing needed? I review (1) the ecological evidence in favor of sparing versus sharing; (2) the evidence from land-use change studies that assesses whether a relationship exists between agricultural intensification and land sparing; and (3) how that relationship may be affected by socioeconomic and political factors. To address the trade-off between biodiversity conservation and food production, I then ask which forms of agricultural intensification can best feed the world now and in the future. On the basis of my review, I suggest that the dichotomy of the land-sparing/land-sharing framework limits the realm of future possibilities to two, largely undesirable, options for conservation. Both large, protected regions and favorable surroundingmatrices are needed to promote biodiversity conservation; they work synergistically and are notmutually exclusive. A “both- and” framing of large protected areas surrounded by a wildlife-friendly matrix suggests different research priorities from the “either-or” framing of sparing versus sharing. Furthermore, wildlife-friendly farming methods such as agroecology may be best adapted to provide food for the world’s hungry people. Download PDF here.

Kremen, C. and M’Gonigle, L.K. “Small-scale restoration in intensive agricultural landscapes supports more specialized and less mobile pollinator species.” Journal of Applied Ecology. DOI: 10.1111/1365-2664.12418

Abstract: Unlike previous studies that suggest habitat restoration in agricultural landscapes only benefits mobile, generalist species, our results suggest that small-scale habitat restoration can promote species whose traits likely render them particularly vulnerable to habitat degradation. Thus, even within highly intensive agricultural landscapes, small-scale habitat restoration can be a conservation management tool. However, tailoring habitat enhancements to promote certain species or guilds may be critical for their success as a conservation intervention in agricultural landscapes. Download PDF here.

Klein, K. “Values-based food procurement in hospitals: the role of health care group purchasing organizations” article in Agriculture and Human Values. 29 January 2015. DOI: 10.1007/s10460-015-9586-y

Excerpt: This paper provides empirical data and analysis on emerging values-based supply chains in hospitals that attempt to meet both the scale-based requirements and values-based goals of alternative food procurement initiatives. In particular, it examines tensions among industrial, economic, and alternative agrifood values in relation to a particular set of hospital supply chain players called Group Purchasing Organizations (GPOs). This study finds that, if alternative agrifood efforts in the health care sector are to integrate with GPO-governed supply chains without losing the robustness of the original values and goals that brought them into being, concerns related to supply chain structure, transparency and traceability of alternative food attributes, and alignment of definitions of local and sustainable food between all supply chain members will need to be addressed. This study also details points of flexibility in health care food supply chains and the potential for hospitals to create purchasing and informational alliances around common food goals in order to create new, values-based supply chain relationships both within and beyond GPO procurement channels. Download PDF here.

Montenegro de Wit, M. “Are we losing diversity? Navigating ecological, political, and epistemic dimensions of agrobiodiversity conservation.” Agriculture and Human Values, Vol. 12, No. 2, Summer 2015. DOI: 10.1007/s10460-015-9642-7

Abstract: Narratives of seed ‘loss’ and ‘persistence’ remain at loggerheads. Crop genetic diversity is rapidly eroding worldwide, we are told, and numerous studies support this claim. Other data, however, suggests an alternative storyline: far from disappearing, seed diversity persists around the world, resisting the homogenizing forces of modern capitalism. Which of these accounts is closer to the truth? As it turns out, crop biodiversity is more easily invoked than measured, more easily wielded than understood. In this essay, I contend that the impasse reveals an error in the asking. We must, instead, look to the ontological, epistemic, and narrative dimensions of agrobiodiversity—and to the science, politics, and cultures of each. How is diversity empirically defined and measured? Who creates and categorizes diversity? Who does not? How is such knowledge mobilized in the accounts and narratives of different interest groups? Where, when, and why does a narrative hold true? This multi-dimensional view of agrobiodiversity makes space for a greater understanding of how diversity is created, maintained, and renewed. It suggests policy and institutional support for systems that engender such renewal of diversity, both in and ex situ. Download PDF here.

Sardiñas, H.S. and Kremen, C. “Pollination services from field-scale agricultural diversification may be context-dependent.” Agriculture, Ecosystems and Environment, 207, 17–25, 2015. DOI: 10.1016/j.agee.2015.03.020

Abstract: Diversification of field edges is widely used as a strategy to augment pollinator populations and, in turn, supplement crop pollination needs. Hedgerow plantings, a commonly applied field-scale diversification technique, have been shown to increase wild bee richness within edges and into crop fields; however, their effects on pollination services in mass-flowering, pollinator-dependent crops typical of large-scale commercial monocultures are less well-known. We evaluated the indirect contribution of hedgerows to sunflower (Helianthus annuus) seed set vis-á-vis wild bee abundance and the interaction between wild bees and managed honey bee pollinators. Although wild bee species richness and the interaction between wild and managed pollinators were significantly associated with augmented seed set, these factors were unrelated to whether a hedgerow was present. The pollinator species foraging within crop fields differed significantly from those found within adjacent hedgerows and bare or weedy field edges, with hedgerows supporting higher species richness than crop fields or unenhanced edges. However, in an independent data set, greater numbers of sunflower-pollinating bees were found in hedgerows than in control edges. Hedgerows may therefore help these crop-pollinating species persist in the landscape. Our findings suggest that hedgerows may not always simultaneously achieve crop pollination and wild bee conservation goals; instead, the benefits of hedgerows may be crop- and region-specific. We recommend evaluation of hedgerow benefits in a variety of crop and landscape contexts to improve their ability to meet ecosystem-service provisioning needs. Download PDF here.

Shattuck, A, Schiavoni, C., and VanGelder, Z. “Translating the Politics of Food Sovereignty: Digging into Contradictions, Uncovering New Dimensions.” Globalizations. Special Issue: Food Sovereignty: Concept, Practice and Social Movements. Volume 12, Issue 4, 2015. DOI: 10.1080/14747731.2015.1041243

Abstract: Food sovereignty, as a movement and a set of ideas, is coming of age. Rooted in resistance to free trade and the globalizing force of neoliberalism, the concept has inspired collective action across the world. We examine what has changed since food sovereignty first emerged on the international scene and reflect on insight from new terrain where the movement has expanded. We argue that to advance the theory and practice of food sovereignty, new frameworks and analytical methods are needed to move beyond binaries—between urban and rural, gender equality and the family farm, trade and localism, and autonomy and engagement with the state. A research agenda in food sovereignty must not shy away from the rising contradictions in and challenges to the movement. The places of seeming contradiction may in fact be where the greatest insights are to be found. We suggest that by taking a relational perspective, scholars can begin to draw insight into the challenges and sticking points of food sovereignty by training their lens on shifts in the global food regime, on the efforts to construct sovereignty at multiple scales, and on the points of translation where food sovereignty is articulated through historical memory, identity, and everyday life. Download PDF here.


Carlisle, L. “Diversity, flexibility, and the resilience effect: lessons from a social-ecological case study of diversified farming in the northern Great Plains, US.” Ecology and Society 19(3):45, 2014. DOI: 10.5751/ES-06736-190345

Abstract: Social-ecological systems are considered resilient when they are capable of recovering from externally forced shocks. Thus, whether a given system is identified as resilient depends on a number of contested definitions: what constitutes a shock, what constitutes a discrete system, and what constitutes acceptable performance. Here, I present a case study in which outcomes apparent to both the researcher and the study subjects demonstrated resilience in effect: a group of farmers in the northern Great Plains in the north-central United States realized economically sufficient production during a low rainfall year when many others in the region did not. However, the researcher’s attempt to model this case as a resilient system was continually challenged by qualitative findings, suggesting that these farmers did not experience the officially decreed “drought” year as a shock. Moreover, the social and ecological processes that produced a “resilience effect” functioned as open systems, and were not readily bounded, even in analytical terms. This is not to suggest that resilience is not an operationalizable concept. Rather, the series of processes which produce a resilience effect may be best understood within a broad framework attentive to diversity, flexibility, and relationships at multiple scales—instead of quantitative models focused on discrete moments of disturbance and adaptation. Download PDF here.

Carlisle, L. “Critical agrarianism.” Renewable Agriculture and Food Systems, 29(02), 135-145, 2014. DOI: 10.1017/S1742170512000427

Abstract: This paper develops the concept of ‘critical agrarianism’ to describe and advance the pursuit of land-based work as a means of realizing social justice and environmental sustainability. Encouraging new agrarianism to more carefully scrutinize its agenda, critical agrarianism celebrates the promise of a close working relationship with the natural world while insisting that a return to the land—per se—is insufficient. In the practice of linking people and land, past and present, critical agrarianism continually questions and reshapes the very category of agrarian, toward a more equitable and enduring prosperity. I revisit both canonical agrarian writing and its critics, pulling out ‘back-pocket tools’ that can keep critical agrarians on track in building our alternative futures. I then offer several case studies of critical agrarianism in practice, encouraging a move beyond idealized models of agrarian ties, toward an empirical account of who has actually been doing the work to put food on the table. Noting the historical gap between working the landscape and having a property or citizenship right, I call for an agrarianism in which practices—not land title—are the basis of material and social community. Furthermore, I suggest that agrarianism must extend its web outward rather than inward, forging connections to the work of land tenure reform, education, community development, immigrant advocacy and trade policy. To be a critical agrarian is not to preserve fixed social-natural ties, but rather to practice a powerfully open and dialogical engagement with the world and one another. Download PDF here.

Frishkoff, L.O., Karp, D.S., M’Gonigle, L.K., Mendenhall, C.D., Zook, J., Kremen, C., Hadly, E.A. and Daily, G.C. “Loss of avian phylogenetic diversity in neotropical agricultural systems.” Science 12, September 2014. Vol. 345, no. 6202, pp. 1343-1346. DOI: 10.1126/science.1254610.

Abstract: Habitat conversion is the primary driver of biodiversity loss, yet little is known about how it is restructuring the tree of life by favoring some lineages over others. We combined a complete avian phylogeny with 12 years of Costa Rican bird surveys (118,127 detections across 487 species) sampled in three land uses: forest reserves, diversified agricultural systems, and intensive monocultures. Diversified agricultural systems supported 600 million more years of evolutionary history than intensive monocultures but 300 million fewer years than forests. Compared with species with many extant relatives, evolutionarily distinct species were extirpated at higher rates in both diversified and intensive agricultural systems. Forests are therefore essential for maintaining diversity across the tree of life, but diversified agricultural systems may help buffer against extreme loss of phylogenetic diversity. Download PDF here.

Garbach, K., Milder, J.C., Montenegro de Wit, M., Karp, D.S., DeClerck, F.A.J. “Biodiversity and Ecosystem Services in Agroecosystems.” Encyclopedia of Agriculture Systems, 2014, Elsevier Science, pp. 21-40.

Abstract: Historically, agricultural systems have been managed to maximize production of food and fiber; however, agricultural landscapes can provide numerous goods and services to society. These include ecosystem services, described as those functions of ecosystems that are useful to humans or support human well-being. Agroecology is the application of ecological concepts and principles to the design and management of sustainable agricultural systems. It includes critical ecosystem services and the organisms, guilds, and ecological communities that provide them. This article explores approaches to measuring, managing, and governing agricultural landscapes and ecosystem services with a focus on agroecology and related methods. Download PDF here. 

Havice, E. and Iles, A. “Shaping the aquaculture sustainability assemblage: Revealing the rule-making behind the rules.” Geoforum, 2014. DOI: 10.008/0016-7185

Abstract: Certification programs yield global assemblages of producers, consumers, investors, markets, and certifiers that are built around rules that define sustainability. In studying the dynamics and impacts of certification, scholars often refer to ‘‘the rules’’ underlying certification in a manner that makes them seem like immutable mobiles: permanent and unchanging objects that are produced by technical, expert-driven processes and that can be applied in diverse places and contexts. In this paper, we turn attention to the rules and rule-making processes underlying certification to demonstrate the unstable, changeable and contested underpinnings of sustainability assemblages. We explore the World Wildlife Fund (WWF)-sponsored multi-stakeholder Aquaculture Dialogues, an unusually open and participatory experiment in ‘‘green’’ rule-making. Our analysis reveals that rules are never final. Instead, intersections between rule-making bodies and the structure of rule-making procedures create critical debate and contestation over the definition of ‘‘sustainability’’ that structures the aquaculture sustainability assemblage, and over who can and should be empowered to do the defining. This approach enables scholars of certification to rethink the ontology of certification rules as part of, rather than an external ordering principle for, the dynamic and contested nature of sustainability assemblages. Download PDF here.

Klein, K. “The Farm Fresh Healthcare Project: Analysis of a Hybrid Values-based Supply Chain.” Journal of Agriculture, Food Systems and Community Development. 7 November 2014. DOI: 10.5304/jafscd.2014.051.003

Excerpt:  This paper highlights the Farm Fresh Healthcare Project (FFHP), a farm-to-hospital initiative in the San Francisco Bay Area that engages a set of hospitals’ existing regional produce distributors to supply products from local small and midscale family farmers. By engaging conventional intermediaries, the project benefited from existing supply chain infrastructure shaped by norms of efficiency, standardization, and affordability. This paper analyzes the extent to which FFHP actors succeed in embedding in their supply chains a range of non-economic values, including transparency, communication of qualities of provenance and production, decision-making equity, environmental stewardship, and social equity in the form of supporting small and midscale family farmers. Download PDF here. 

Montenegro de Wit, M. “A Lighthouse for Urban Agriculture: University, Community, and Redefining Expertise in the Food System.” Gastronomica: The Journal of Food and Culture, Spring 2014. Vol. 14, no. 1, pp. 9-22. DOI: 10.1525/gfc.2014.14.1.9.

Abstract: This article advances the concept of the agroecological ‘‘lighthouse’’ as a civic space for learning and participating in the principles and practices of urban food production. As urbanization threatens to encourage the increased industrialization of agriculture, growing food in cities promises to alleviate this pressure while creating new opportunities for community empowerment and greater access to sustainable, healthy, and affordable food. This kind of transition, I argue, will demand social relations that bridge science, practice, and movement—and that cut in surprising ways across traditional boundaries between university and community. Drawing from a recent experience in an Urban Agroecology shortcourse in Berkeley, California, I illustrate what such relationships might look like, profiling the caretaker of one backyard garden in the Bay Area. This urban grower effuses what James Scott calls metis, moving fluidly across institutional boundaries, experimenting with agroecological innovations, and offering his space as a lighthouse commons for participatory learning. Interestingly, he is not a PhD, but a retired postal worker. With the stakes mounting for progress in food security across the urban-rural divide, the agroecological lighthouse opens up potential for new researcher-farmer partnerships as well as a means for expanding what we consider legitimate knowledge-making communities. Advancing the notion of a ‘‘lighthouse extension model,’’ I challenge the discourse of mainstream cooperative extension, arguing that a more egalitarian food system will likely emerge from participation by those traditionally excluded from shaping it. Download PDF here.

Morandin, L.A., Long, R.F. and Kremen, C. “Hedgerows enhance beneficial insects on adjacent tomato fields in an intensive agricultural landscape.”  Agriculture, Ecosystems and Environment, May 1, 2014. Vol. 189, pp. 164-170. DOI: 10.1016/j.agee.2014.03.030

Abstract: Within-farm habitat enhancements such as hedgerows could aid pest control in adjacent crops; how- ever, there is little information on whether small-scale restoration impacts pests and natural enemies, and crop damage, and how far effects may extend into fields. We compared restored, California native perennial hedgerows to unenhanced field edges consisting of commonly occurring semi-managed, non- native weeds. Pest and natural enemy communities were assessed in both edge types and into adjacent processing tomato fields. Using sentinel pest eggs, pest control was quantified, and pest pressure and crop damage was compared between field types. Economically-important pests were fewer and parasitoid wasps were more abundant in hedgerows than weedy crop edges. There was no difference in predatory arthropod abundance between edge types, but there was greater predator richness in hedgerow than weedy edges. Predatory lady beetles were more abundant and aphids were lower in fields with hedgerows, up to 200 m into fields, the maximum extent of observations. Fewer of the fields adjacent to hedgerows reached threshold pest levels requiring insecticide application. Benefits of hedgerows to pest control from parasitism extended to 100 m but not 200 m into fields. Farm-scale hedgerow restoration can provide pest control benefits up to 100 or 200 m into fields and multiple hedgerows around fields could enhance pest control throughout entire fields, reducing the need for chemical pest control. Download PDF here.

Ponisio L.C., M’Gonigle L.K., Mace K.C., Palomino J., de Valpine P., Kremen C. “Diversification practices reduce organic to conventional yield gap.”  Proceedings of the Royal Society B: Biological Sciences, December 2014. Vol. 282. DOI: 10.1098/rspb.2014.1396.

Abstract: Agriculture today places great strains on biodiversity, soils, water and the atmosphere, and these strains will be exacerbated if current trends in population growth, meat and energy consumption, and food waste continue. Thus, farming systems that are both highly productive and minimize environmental harms are critically needed. Howorganic agriculture may contribute to world food production has been subject to vigorous debate over the past decade. Here, we revisit this topic comparing organic and conventional yields with a new meta-dataset three times larger than previously used (115 studies containing more than 1000 observations) and a new hierarchical analytical framework that can better account for the heterogeneity and structure in the data. We find organic yields are only 19.2% (+3.7%) lower than conventional yields, a smaller yield gap than previous estimates. More importantly, we find entirely different effects of crop types and management practices on the yield gap compared with previous studies. For example, we found no significant differences in yields for leguminous versus non-leguminous crops, perennials versus annuals or developed versus developing countries. Instead, we found the novel result that two agricultural diversification practices, multi-cropping and crop rotations, substantially reduce the yield gap (to 9+4% and 8+5%, respectively) when the methods were applied in only organic systems. These promising results, based on robust analysis of a larger meta-dataset, suggest that appropriate investment in agroecological research to improve organic management systems could greatly reduce or eliminate the yield gap for some crops or regions. Download PDF here. 

Rogé, P., Friedman, A.R., Astier, M. and Altieri, M.A. “Farmer Strategies for Dealing with Climatic Variability: A Case Study from the Mixteca Alta Region of Oaxaca, Mexico.” Agroecology and Sustainable Food Systems, July 2014. Vol 38, No. 7, pp. 786-811. DOI: 10.1080/21683565.2014.900842.

Abstract: This study describes an interdisciplinary methodology for helping small farmers prepare for climatic variability. We facilitated workshops in the Mixteca Alta region of Oaxaca, Mexico, in which groups of small farmers described how they had adapted to and prepared for past climate challenges. Farmers reported that their cropping systems were changing for multiple reasons: more drought, later rainfall onset, decreased rural labor, and introduced labor-saving technologies. Examination of climate data found that farmers’ climate narratives were largely consistent with the observational record. There have been increases in temperature and rainfall intensity, and an increase in rainfall seasonality that may be perceived as later rainfall onset. Farmers also identified 14 indicators that they subsequently used to evaluate the condition of their agroecosystems. Farmers ranked landscape-scale indicators as more marginal than farmer management or soil quality indicators. From this analysis, farmers proposed strategies to improve the ability of their agroecosystems to cope with climatic variability. Notably, they recognized that social organizing and education are required for landscape-scale indicators to be improved. This outcome suggests that climate change adaptation by small farmers involves much more than just a set of farming practices, but also community action to tackle collective problems. Download the PDF here. 


Bacon, C.M., Getz, C., Kraus, S., Montenegro de Wit, M. and Holland, K. “The Social Dimensions of Sustainability and Change in Diversified Farming Systems.”  Ecology and Society, March 2013. Vol. 17, No. 4, Art. 41. DOI: 10.5751/ES-05226-170441

Abstract: Agricultural systems are embedded in wider social-ecological processes that must be considered in any complete discussion of sustainable agriculture. Just as climatic profiles will influence the future viability of crops, institutions, i.e., governance agreements, rural household and community norms, local associations, markets, and agricultural ministries, to name but a few, create the conditions that foster sustainable food systems. Because discussions of agricultural sustainability often overlook the full range of social dimensions, we propose a dual focus on a broad set of criteria, i.e., human health, labor, democratic participation, resiliency, biological and cultural diversity, equity, and ethics, to assess social outcomes, and on institutions that could support diversified farming systems (DFS). A comparative analysis of case studies from California’s Central Valley, Mesoamerican coffee agroforestry systems, and European Union agricultural parks finds that DFS practices are unevenly adopted within and among these systems and interdependent with institutional environments that specifically promote diversified farming practices. Influential institutions in these cases include state policies, farmers’ cooperatives/associations, and organized civic efforts to influence agroenvironmental policy, share knowledge, and shape markets for more ‘sustainable’ products. The Californian and Mesoamerican cases considers organic and fair trade certifications, finding that although they promote several DFS practices and generate social benefits, they are inadequate as a single strategy to promote agricultural sustainability. The complex governance and multifunctional management of Europe’s peri-urban agricultural parks show unexpected potential for promoting DFS. Unless DFS are anchored in supportive institutions and evaluated against an inclusive set of social and environmental criteria, short-term investments to advance diversified agriculture could miss a valuable opportunity to connect ecological benefits with social benefits in the medium and long terms. Download PDF here.

Bowman, M.S. and Zilberman, D. “Economic Factors Affecting Diversified Farming Systems.”  Ecology and Society,March 2013. Vol. 18, No. 1, Art. 33. DOI: 10.5751/ES-05574-180133.

Abstract: In response to a shift toward specialization and mechanization during the 20th century, there has been momentum on the part of a vocal contingent of consumers, producers, researchers, and policy makers who call for a transition toward a new model of agriculture. This model employs fewer synthetic inputs, incorporates practices which enhance biodiversity and environmental services at local, regional, and global scales, and takes into account the social implications of production practices, market dynamics, and product mixes. Within this vision, diversified farming systems (DFS) have emerged as a model that incorporates functional biodiversity at multiple temporal and spatial scales to maintain ecosystem services critical to agricultural production. Our aim is to provide an economists’ perspective on the factors which make diversified farming systems (DFS) economically attractive, or not-so-attractive, to farmers, and to discuss the potential for and roadblocks to widespread adoption. We focus on how a range of existing and emerging factors drive profitability and adoption of DFS. We believe that, in order for DFS to thrive, a number of structural changes are needed. These include: 1) public and private investment in the development of low-cost, practical technologies that reduce the costs of production in DFS, 2) support for and coordination of evolving markets for ecosystem services and products from DFS and 3) the elimination of subsidies and crop insurance programs that perpetuate the unsustainable production of staple crops. We suggest that subsidies and funding be directed, instead, toward points 1) and 2), as well as toward incentives for consumption of nutritious food. Download PDF here. 

Carlisle, L. and Miles, A. “Closing the Knowledge Gap: How the USDA Could Tap the Potential of Biologically Diversified Farming Systems.”  Journal of Agriculture, Food Systems, and Community Development, Vol. 3, Issue 4, September 24, 2013, pp. 219–225. DOI: 10.5304/jafscd.2013.034.025.

Abstract: Modern agriculture has proven highly productive, yet has simultaneously generated environmental and social impacts of global concern. Pressing environmental issues call into question the ability of the current model of industrial agriculture to sustain adequate yields without undermining the natural resource base upon which it depends. Meanwhile, global food needs are projected to double by 2050, raising questions over the need to further intensify agricultural production. Current research demonstrates that biologically diversified farming systems can meet global food needs sustainably and efficiently, as they outperform chemically managed monocultures across a wide range of globally important ecosystem services while producing sufficient yields and reducing resource waste throughout the food system. Research and development related to diversified systems, however, commands less than two percent of public agricultural research funding. We argue that this “knowledge gap” is at the crux of the “yield gap” that is often raised as the impediment to transitioning a greater share of global agriculture to diversified, agroecological production. If United States Department of Agriculture (USDA) research, education, and extension were to shift significantly toward agroecology and biologically diversified farming systems, the potential to address global resource challenges would be enormous. Here we present a broad framework for how the USDA could use existing infrastructure to address the challenges of food and farming in the twenty-first century and beyond.

In 2012, the CDSF produced an edited volume for the journal Ecology and Society defining the concept of diversified farming systems and their environmental, social, economic and policy ramifications. Download PDF here.

Chaplin-Kramer, R., de Valpine, P., Mills, N.J. and Kremen, C. “Detecting pest control services across spatial and temporal scales.”  Agriculture, Ecosystems, and Environment, December 1, 2013. Vol. 181, pp. 206-212. DOI: 10.1016/j.agee.2013.10.007

Abstract: Natural habitat may deliver ecosystem services to agriculture through the provision of natural enemies of agricultural pests. Natural or non-crop habitat has strongly positive effects on natural enemies in cropland, but the resulting impact on pests is not as well established. This study measured weekly natural enemy (syrphid fly larvae) and pest (cabbage aphid) abundances in Central California broccoli fields for three years. Abundance of syrphid fly larvae increased strongly with the proportion of natural habitat surrounding the farm. As the density of syrphid fly larvae increased, weekly aphid population growth rates slowed, such that aphid densities just prior to harvest were lowest in farms with natural habitat. These landscape-mediated impacts of syrphids on aphids were not evident when data were aggregated into annual averages, a common metric in research on pest control services. We suggest that higher temporal resolution of data for natural enemy and pest abundance can reveal top–down control that is otherwise masked by seasonal and interannual variation in environmental factors. Download PDF here. 

Iles, A. and Marsh, R. “Nurturing Diversified Farming Systems in Industrialized Countries: How Public Policy Can Contribute.” Ecology and Society, March 2013. Vol. 17, No. 4, Art. 42. DOI: 10.5751/ES-05041-170442

Abstract: If diversified farming systems (DFS) are to thrive again in the United States, policies and preferences must evolve to reward the environmental and social benefits of sustainable farming and landscape management. Compared with conventional agricultural policies, policies aiding ecological diversification are underdeveloped and fragmented. We consider several examples of obstacles to the adoption and spread of diversified farming practices in the U.S. industrialized agricultural system. These include the broader political economic context of industrialized agriculture, the erosion of farmer knowledge and capacity, and supply chain and marketing conditions that limit the ability of farmers to adopt sustainable practices. To overcome these obstacles and nurture DFS, policy makers, researchers, industry, farmers, consumers, and local communities can play pivotal roles to transform agricultural research, develop peer-to-peer learning processes, support the recruitment and retention of new farmers through access to credit and land, invest in improved agricultural conservation programs, provide compensation for provision of ecological services in working landscapes, and develop links to consumer and institutional markets. Download PDF here.

Jha, S. and Kremen, C. “Resource diversity and landscape-level homogeneity drive native bee foraging.”  PNAS,January 8, 2013. Vol. 110, No. 2, pp. 555-558. DOI: 10.1073/pnas.1208682110

Abstract: Given widespread declines in pollinator communities and increasing global reliance on pollinator-dependent crops, there is an acute need to develop a mechanistic understanding of native pollinator population and foraging biology. Using a population genetics approach, we determine the impact of habitat and floral resource distributions on nesting and foraging patterns of a critical native pollinator, Bombus vosnesenskii. Our findings demonstrate that native bee foraging is far more plastic and extensive than previously believed and does not follow a simple optimal foraging strategy. Rather, bumble bees forage further in pursuit of species-rich floral patches and in landscapes where patch-to-patch variation in floral resources is less, regardless of habitat composition. Thus, our results reveal extreme foraging plasticity and demonstrate that floral diversity, not density, drives bee foraging distance. Further- more, we find a negative impact of paved habitat and a positive impact of natural woodland on bumble bee nesting densities. Over- all, this study reveals that natural and human-altered landscapes can be managed for increased native bee nesting and extended foraging, dually enhancing biodiversity and the spatial extent of pollination services. Download PDF here.

Kennedy, C.M., Lonsdorf, E., Neel, M.C., Williams, N.M., Ricketts, T.H., Winfree, R., Bommarco, R., Brittain, C., Burley, A.L., Cariveau, D., Carvalheiro, L.G., Chacoff, N.P., Cunningham, S.A., Danforth, B.N., Dudenhoffer, J., Elle, E., Gaines, H.R., Garibaldi, L.A., Gratton, C., Holzschuh, A., Isaacs, R., Javorek, S.K., Jha, S., Klein, A.M., Krewenka, K., Mandelik, Y., Mayfield, M.M., Morandin, L., Neame, L.A., Otieno, M., Park, M., Potts, S.G., Rundlof, M., Saez, A., Steffan-Dewenter, I., Taki, H., Viana, B.F.; Westphal, C., Wilson, J.K., Greenleaf, S.S. and Kremen, C. “A global quantitative synthesis of local and landscape effects on wild bee pollinators in agroecosystems.”  Ecology Letters, May 2013. Vol. 16, Issue 5, pp. 584-599. DOI: 10.1111/ele.12082

Abstract: Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 crop systems globally. Bee abundance and richness were higher in diversified and organic fields and in land- scapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Bee responses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on both the maintenance of high-quality habitats around farms and on local management practices that may offset impacts of intensive monoculture agriculture. Download PDF here.

Kremen, C., Iles, A. and Bacon, C. “Diversified Farming Systems: An Agroecological, Systems-based Alternative to Modern Industrial Agriculture.”  Ecology and Society, March 2013. Vol. 17, No. 4, Art. 44. DOI: 10.5751/ ES-05103-170444

Abstract: This Special Issue on Diversified Farming Systems is motivated by a desire to understand how agriculture designed according to whole systems, agroecological principles can contribute to creating a more sustainable, socially just, and secure global food system. We first define Diversified Farming Systems (DFS) as farming practices and landscapes that intentionally include functional biodiversity at multiple spatial and/or temporal scales in order to maintain ecosystem services that provide critical inputs to agriculture, such as soil fertility, pest and disease control, water use efficiency, and pollination. We explore to what extent DFS overlap or are differentiated from existing concepts such as sustainable, multifunctional, organic or ecoagriculture. DFS are components of social-ecological systems that depend on certain combinations of traditional and contemporary knowledge, cultures, practices, and governance structures. 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. We explore how social institutions, particularly alternative agri-food networks and agrarian movements, may serve to promote DFS approaches, but note that such networks and movements have other primary goals and are not always explicitly connected to the environmental and agroecological concerns embodied within the DFS concept. We examine global trends in agriculture to investigate to what extent industrialized forms of agriculture are replacing former DFS, assess the current and potential contributions of DFS to food security, food sovereignty and the global food supply, and determine where and under what circumstances DFS are expanding rather than contracting. Download PDF here. 

Kremin, C. and Miles, A. “Ecosystem Services in Biologically Diversified versus Conventional Farming Systems: Benefits, Externalities, and Trade-Offs.”  Ecology and Society, March 2013. Vol. 17, No. 4, Art. 40. DOI: 10.5751/ES-05035-170440.

Abstract: We hypothesize that biological diversification across ecological, spatial, and temporal scales maintains and regenerates the ecosystem services that provide critical inputs—such as maintenance of soil quality, nitrogen fixation, pollination, and pest control—to agriculture. Agrobiodiversity is sustained by diversified farming practices and it also supplies multiple ecosystem services to agriculture, thus reducing environmental externalities and the need for off-farm inputs. We reviewed the literature that compares biologically diversified farming systems with conventional farming systems, and we examined 12 ecosystem services: biodiversity; soil quality; nutrient management; water-holding capacity; control of weeds, diseases, and pests; pollination services; carbon sequestration; energy efficiency and reduction of warming potential; resistance and resilience to climate change; and crop productivity. We found that compared with conventional farming systems, diversified farming systems support substantially greater biodiversity, soil quality, carbon sequestration, and water-holding capacity in surface soils, energy-use efficiency, and resistance and resilience to climate change. Relative to conventional monocultures, diversified farming systems also enhance control of weeds, diseases, and arthropod pests and they increase pollination services; however, available evidence suggests that these practices may often be insufficient to control pests and diseases or provide sufficient pollination. Significantly less public funding has been applied to agroecological research and the improvement of diversified farming systems than to conventional systems. Despite this lack of support, diversified farming systems have only somewhat reduced mean crop productivity relative to conventional farming systems, but they produce far fewer environmental and social harms. We recommend that more research and crop breeding be conducted to improve diversified farming systems and reduce yield gaps when they occur. Because single diversified farming system practices, such as crop rotation, influence multiple ecosystem services, such research should be holistic and integrated across many components of the farming system. Detailed agroecological research especially is needed to develop crop- and region-specific approaches to control of weeds, diseases, and pests. Download PDF here. 

Morandin, L.A. and Kremen, C. “Hedgerow restoration promotes pollinator populations and exports native bees to adjacent fields.”  Ecological Applications, June 2013. Vol. 23, Issue 4, pp. 829-839. DOI: 10.1890/12-1051.1

Abstract: In intensive agricultural landscapes, restoration within farms could enhance biodiversity and ecosystem services such as pollination by native pollinators. Although governments and conservation groups are promoting small-scale restoration on working farms, there are few studies that assess whether these practices enhance pollinator communities in restored areas. Further, there is no information on whether floral enhancements will deplete pollinators in adjacent fields by concentrating ambient populations or whether they result in a net increase in abundance in adjacent farm fields. We investigated whether field edges restored with native perennial plants in California’s Central Valley agricultural region increased floral abundance and potential bee nesting sites, and native bee and syrphid fly abundance and diversity, in comparison to relatively unmanaged edges. Native bees and syrphid flies collected from flowers were more abundant, species-rich, and diverse at hedgerow sites than in weedy, unmanaged edges. Abundance of bees collected passively in pan traps was negatively correlated with floral abundance, was significantly different from communities captured by net sampling from flowers, and did not distinguish between site types; we therefore focused on the results of net samples and visual observations. Uncommon species of native bees were sevenfold more abundant on hedgerow flowers than on flowers at weedy, unmanaged edges. Of the species on flowers at hedgerows, 40% were exclusive to hedgerow sites, but there were no species exclusively found on flowers at control sites. Hedgerows were especially important for supporting less-common species of native bees in our intensive agricultural landscape. Hedgerows did not concentrate ambient native bee, honey bee, or syphid fly populations, and they acted as net exporters of native bees into adjacent fields. Within-farm habitat restoration such as hedgerow creation may be essential for enhancing native pollinator abundance and diversity, and for pollination services to adjacent crops. Download PDF here.

Morandin, L.A. and Kremen, C. “Bee Preference for Native versus Exotic Plants in Restored Agricultural Hedgerows.”  Restoration Ecology, July 5, 2013. Vol. 21, Issue 1, pp. 26-32. DOI: 10.1111/j.1526-100X.2012.00876.x

Abstract: Habitat restoration to promote wild pollinator populations is becoming increasingly common in agricultural lands. Yet, little is known about how wild bees, globally the most important wild pollinators, use resources in restored habitats. We compared bee use of native and exotic plants in two types of restored native plant hedgerows: mature hedgerows (>10 years from establishment) designed for natural enemy enhancement and new hedgerows (≤2 years from establishment) designed to enhance bee populations. Bees were collected from flowers using timed aerial net- ting and flowering plant cover was estimated by species using cover classes. At mature hedgerow sites, wild bee abundance, richness, and diversity were greater on native plants than exotic plants. At new sites, where native plants were small and had limited floral display, abundance of bees was greater on native plants than exotic plants; but, controlling for floral cover, there was no difference in bee diversity and richness between the two plant types. At both mature and new hedgerows, wild bees preferred to forage from native plants than exotic plants. Honey bees, which were from managed colonies, also preferred native plants at mature hedgerow sites but exhibited no preference at new sites. Our study shows that wild bees, and managed bees in some cases, prefer to forage on native plants in hedgerows over co-occurring weedy, exotic plants. Semi- quantitative ranking identified which native plants were most preferred. Hedgerow restoration with native plants may help enhance wild bee abundance and diversity, and maintain honey bee health, in agricultural areas. Download PDF here.

Sayre, N.F., Carlisle, L., Huntsinger, L., Fisher, G and Shattuck, A. “The Role of Rangelands in Diversified Farming Systems: Innovations, Obstacles, and Opportunities in the USA.” Ecology and Society, March 2013. Vol. 17, No. 4, Art. 43. DOI: 10.5751/ES-04790-170443

Abstract: Discussions of diversified farming systems (DFS) rarely mention rangelands: the grasslands, shrublands, and savannas that make up roughly one-third of Earth’s ice-free terrestrial area, including some 312 million ha of the United States. Although ranching has been criticized by environmentalists for decades, it is probably the most ecologically sustainable segment of the U.S. meat industry, and it exemplifies many of the defining characteristics of DFS: it relies on the functional diversity of natural ecological processes of plant and animal (re)production at multiple scales, based on ecosystem services generated and regenerated on site rather than imported, often nonrenewable, inputs. Rangelands also provide other ecosystem services, including watershed, wildlife habitat, recreation, and tourism. Even where non-native or invasive plants have encroached on or replaced native species, rangelands retain unusually high levels of plant diversity compared with croplands or plantation forests. Innovations in management, marketing, incentives, and easement programs that augment ranch income, creative land tenure arrangements, and collaborations among ranchers all support diversification. Some obstacles include rapid landownership turnover, lack of accessible U.S. Department of Agriculture certified processing facilities, tenure uncertainty, fragmentation of rangelands, and low and variable income, especially relative to land costs. Taking advantage of rancher knowledge and stewardship, and aligning incentives with production of diverse goods and services, will support the sustainability of ranching and its associated public benefits. The creation of positive feedbacks between economic and ecological diversity should be the ultimate goal. Download PDF here. 


Altieri, M. A. “Convergence or Divide in the Movement for Sustainable and Just Agriculture.”  Organic Fertilisation, Soil Quality, and Human Health, Sustainable Agriculture Reviews, 2012, Vol. 9, pp. 1-10. DOI: 10.1007/978-94-007-4113-3_1

Abstract: ‘Greening’ the green revolution will not be sufficient to reduce hunger and poverty and conserve biodiversity. The increasing cost of oil and fertilizers, and the deterioration of the climate and global ecology are key factors that undermine the capacity of humankind to feed itself. This phenomena became evident when the ‘perfect storm’ occurred in 2008 with the alarming rise in the cost of food that sent an additional 75 million people to the world’s line of hungry people. Disregarding the above issues the ruling international agricultural class continues asserting that food production will have to be increased by 70% by the year 2050. The threat to global food insecurity is the direct result of the industrial model of agriculture characterized by large-scale monocultures tailored for the export markets. We need an alternative agricultural development paradigm, one that encourages more ecologically, biodiverse, sustainable and socially just forms of agriculture.

Strategies are needed which lead to the revitalization of small and medium sized farms, and point the way towards the reshaping of the entire agricultural policy and food system in ways that are economically viable to farmers and consumers. Proposed ‘sustainable intensification’ is ideologically buttressed by intellectual projects to reframe and redefine agroecology by stripping it of its political and social content and promote the wrong notion that agroecological methods can co-exist alongside the aggressive expansion of transgenic crops and agrofuels. Many environmental and advocacy groups privilege those with access to capital and perpetuate an ‘agriculture of the poor for the rich’. The technological determinism that the organic agriculture movement emphasizes via development and dissemination of low-input or appropriate technologies is not only naïve but dangerous, as it assumes these technologies in themselves have the capability of initiating beneficial social changes. Download PDF here.

Chaplin-Kramer, R. and Kremen, C. “Pest control experiments show benefits of complexity at landscape and local scales.”  Ecological Applications, October 2012. Vol. 22, No. 7, pp. 1936-1948. DOI: 10.1890/11-1844.1

Abstract: Farms benefit from pest control services provided by nature, but management of these services requires an understanding of how habitat complexity within and around the farm impacts the relationship between agricultural pests and their enemies. Using cage experiments, this study measures the effect of habitat complexity across scales on pest suppression of the cabbage aphid Brevicoryne brassicae in broccoli. Our results reveal that proportional reduction of pest density increases with complexity both at the landscape scale (measured by natural habitat cover in the 1 km around the farm) and at the local scale (plant diversity). While high local complexity can compensate for low complexity at landscape scales and vice versa, a delay in natural enemy arrival to locally complex sites in simple landscapes may compromise the enemies’ ability to provide adequate control. Local complexity in simplified landscapes may only provide adequate top-down pest control in cooler microclimates with relatively low aphid colonization rates. Even so, strong natural enemy function can be overwhelmed by high rates of pest reproduction or colonization from nearby source habitat. Download PDF here.

Mandelik, Y., Winfree, R., Neeson, T. and Kremen, C. “Complementary habitat use by wild bees in agro-natural landscapes.”  Ecological Applications, July 2012. Vol. 22, No. 5, pp. 1535-1546.

Abstract: Human activity causes abrupt changes in resource availability across the landscape. In order to persist in human-altered landscapes organisms need to shift their habitat use accordingly. Little is known about the mechanisms by which whole communities persist in human-altered landscapes, including the role of complementary habitat use. We define complementary habitat use as the use of different habitats at different times by the same group of species during the course of their activity period. We hypothesize that complementary habitat use is a mechanism through which native bee species persist in human-altered landscapes. To test this idea, we studied wild bee communities in agro-natural landscapes and explored their community-level patterns of habitat and resource use over space and time. The study was conducted in six agro-natural landscapes in the eastern United States, each containing three main bee habitat types (natural habitat, agricultural fields, and old fields). Each of the three habitats exhibited a unique seasonal pattern in amount, diversity, and composition of floral resources, and together they created phenological complementarity in foraging resources for bees. Individual bee species as well as the bee community responded to these spatiotemporal patterns in floral availability and exhibited a parallel pattern of complementary habitat use. The majority of wild bee species, including all the main crop visitors, used fallow areas within crops early in the season, shifted to crops in mid-season, and used old-field habitats later in the season. The natural-forest habitat supported very limited number of bees, mostly visitors of non-crop plants. Old fields are thus an important feature in these arable landscapes for maintaining crop pollination services. Our study provides a detailed examination of how shifts in habitat and resource use may enable bees to persist in highly dynamic agro-natural landscapes, and points to the need for a broad cross-habitat perspective in managing these landscapes. Download PDF here.

Nicholls, C.I. and Altieri, M.A. “Plant biodiversity enhances bees and other insect pollinators in agroecosystems. A review.”  Agronomy for Sustainable Development, June 2012. DOI: 10.1007/s13593-012-0092-y

Abstract: Thirty-five percent of global production from crops including at least 800 cultivated plants depend on animal pollination. The transformation of agriculture in the past half-century has triggered a decline in bees and other insect pollinators. In North America, losses of bee colonies have accelerated since 2004, leaving the continent with fewer man- aged pollinators than at any time in the past 50 years. A number of factors linked to industrial modes of agriculture affect bee colonies and other pollinators around the world, ranging from habitat degradation due to monocultures with consequent declines in flowering plants and the use of dam- aging insecticides. Incentives should be offered to farmers to restore pollinator-friendly habitats, including flower provi- sioning within or around crop fields and elimination of use of insecticides by adopting agroecological production meth- ods. Conventional farmers should be extremely cautious in the choice, timing, and application of insecticides and other chem- icals. Here, we review the literature providing mounting evi- dence that the restoration of plant biodiversity within and around crop fields can improve habitat for domestic and wild bees as well as other insects and thus enhance pollination services in agroecosystems. Main findings are the following: (1) certain weed species within crop fields that provide food resources and refuge should be maintained at tolerable levels within crop fields to aid in the survival of viable populations of pollinators. (2) Careful manipulation strategies need to be defined in order to avoid weed competition with crops and interference with certain cultural practices. Economic thresh- olds of weed populations, as well as factors affecting crop– weed balance within a crop season, need to be defined for specific cropping systems. (3) More research is warranted to advance knowledge on identifying beneficial weed species and ways to sponsor them to attract pollinators while not reducing yields through interference. (4) In areas of intensive farming, field margins, field edges and paths, headlands, fence-lines, rights of way, and nearby uncultivated patches of land are important refuges for many pollinators. (5) Main- tenance and restoration of hedgerows and other vegetation features at field borders is therefore essential for harboring pollinators. (6) Appropriate management of non-cropped areas to encourage wild pollinators may prove to be a cost- effective means of maximizing crop yield. Download PDF here.

Klein, A., Brittain, C., Hendrix, S.D., Thorp, R., Williams, N. and Kremen, C. “Wild pollination services to California almond rely on semi-natural habitat.”  Journal of Applied Ecology, June 2012. Vol. 49, Issue 3, pp. 723-732. DOI: 10.1111/j.1365-2664.2012.02144.x

Abstract: 1. Global declines in honeybees have led to concerns about negative impacts on food production because of low levels of pollination. This is exemplified in California where the demand for honey- bees Apis mellifera to pollinate almond Prunus dulcis is increasing, but problems with honeybee health suggest it may not be sustainable to rely solely on the pollination service of a single species. 2. We investigated the effect of the quantity of surrounding natural habitat, organic management and strips of semi-natural vegetation on flower visitation frequency of wild and managed pollinators and fruit set in 23 California almond orchards (15 conventional, 8 organic). Five conventional and four organic orchards were surrounded by a low percentage (<5%) of natural or semi-natural habitat in a 1-km radius and another five conventional and four organic orchards were surrounded by a high percentage of these habitats(>30%).A further five conventional orchards with a low percentage of surrounding natural habitat had an adjacent strip of semi-natural vegetation and were included in the study to represent a realistic option for orchard management in intensive agricultural landscapes. 3. Wild bee species visited almond flowers but only in orchards with adjacent semi-natural habitat or vegetation strips. Organic management increased the flower visitation frequencies of hover flies and wild bees. The presence of a strip of semi-natural vegetation in orchards with a low percentage of surrounding natural habitat increased the number of species and the flower visitation frequency by wild pollinators but only at orchard edges and not to the degree seen when natural habitat was abundant. 4. Wild bee species richness and flower visitation frequency, but not honeybee frequency, were related to fruit set. Fruit set increased with increasing percentage of natural habitat surrounding the orchards. Organic farming or the presence of a vegetation strip did not increase fruit set. 5. Synthesis and applications. The restoration of high quality habitat strips along the edges of crop fields in highly intensified agricultural landscapes should be encouraged and monitored to conserve pollinators and to determine whether benefits for agriculture can be realized. Although honeybees are the main and most important pollinating insects for many plants, wild pollinators may be necessary to ensure high fruit set. Organic farming alone will not sustain wild pollination services for almond in California. Download PDF here.