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Browsing by Author "Karp, Daniel S."

Now showing 1 - 4 of 4
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    Archetype models upscale understanding of natural pest control response to land-use change
    Alexandridis, Nikolaos; Marion, Glenn; Chaplin-Kramer, Rebecca; Dainese, Matteo; Ekroos, Johan; Grab, Heather; Jonsson, Mattias; Karp, Daniel S.; Meyer, Carsten; O'Rourke, Megan E.; Pontarp, Mikael; Poveda, Katja; Seppelt, Ralf; Smith, Henrik G.; Walters, Richard J.; Clough, Yann; Martin, Emily A. (Wiley, 2022-06)
    Control of crop pests by shifting host plant availability and natural enemy activity at landscape scales has great potential to enhance the sustainability of agriculture. However, mainstreaming natural pest control requires improved understanding of how its benefits can be realized across a variety of agroecological contexts. Empirical studies suggest significant but highly variable responses of natural pest control to land-use change. Current ecological models are either too specific to provide insight across agroecosystems or too generic to guide management with actionable predictions. We suggest obtaining the full benefit of available empirical, theoretical, and methodological knowledge by combining trait-mediated understanding from correlative studies with the explicit representation of causal relationships achieved by mechanistic modeling. To link these frameworks, we adapt the concept of archetypes, or context-specific generalizations, from sustainability science. Similar responses of natural pest control to land-use gradients across cases that share key attributes, such as functional traits of focal organisms, indicate general processes that drive system behavior in a context-sensitive manner. Based on such observations of natural pest control, a systematic definition of archetypes can provide the basis for mechanistic models of intermediate generality that cover all major agroecosystems worldwide. Example applications demonstrate the potential for upscaling understanding and improving predictions of natural pest control, based on knowledge transfer and scientific synthesis. A broader application of this mechanistic archetype approach promises to enhance ecology's contribution to natural resource management across diverse regions and social-ecological contexts.
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    Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
    Karp, Daniel S.; O'Rourke, Megan E. (NAS, 2018-06-11)
    The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
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    A global synthesis reveals biodiversity-mediated benefits for crop production
    Dainese, Matteo; Martin, Emily A.; Aizen, Marcelo A.; Albrecht, Matthias; Bartomeus, Ignasi; Bommarco, Riccardo; Carvalheiro, Luisa G.; Chaplin-Kramer, Rebecca; Gagic, Vesna; Garibaldi, Lucas A.; Ghazoul, Jaboury; Grab, Heather; Jonsson, Mattias; Karp, Daniel S.; Kennedy, Christina M.; Kleijn, David; Kremen, Claire; Landis, Douglas A.; Letourneau, Deborah K.; Marini, Lorenzo; Poveda, Katja; Rader, Romina; Smith, Henrik G.; Tscharntke, Teja; Andersson, Georg K. S.; Badenhausser, Isabelle; Baensch, Svenja; Bezerra, Antonio Diego M.; Bianchi, Felix J. J. A.; Boreux, Virginie; Bretagnolle, Vincent; Caballero-Lopez, Berta; Cavigliasso, Pablo; Cetkovic, Aleksandar; Chacoff, Natacha P.; Classen, Alice; Cusser, Sarah; da Silva e Silva, Felipe D.; de Groot, G. Arjen; Dudenhoeffer, Jan H.; Ekroos, Johan; Fijen, Thijs; Franck, Pierre; Freitas, Breno M.; Garratt, Michael P. D.; Gratton, Claudio; Hipolito, Juliana; Holzschuh, Andrea; Hunt, Lauren; Iverson, Aaron L.; Jha, Shalene; Keasar, Tamar; Kim, Tania N.; Kishinevsky, Miriam; Klatt, Bjorn K.; Klein, Alexandra-Maria; Krewenka, Kristin M.; Krishnan, Smitha; Larsen, Ashley E.; Lavigne, Claire; Liere, Heidi; Maas, Bea; Mallinger, Rachel E.; Martinez Pachon, Eliana; Martinez-Salinas, Alejandra; Meehan, Timothy D.; Mitchell, Matthew G. E.; Molina, Gonzalo A. R.; Nesper, Maike; Nilsson, Lovisa; O'Rourke, Megan E.; Peters, Marcell K.; Plecas, Milan; Potts, Simon G.; Ramos, Davi de L.; Rosenheim, Jay A.; Rundlof, Maj; Rusch, Adrien; Saez, Agustin; Scheper, Jeroen; Schleuning, Matthias; Schmack, Julia M.; Sciligo, Amber R.; Seymour, Colleen; Stanley, Dara A.; Stewart, Rebecca M.; Stout, Jane C.; Sutter, Louis; Takada, Mayura B.; Taki, Hisatomo; Tamburini, Giovanni; Tschumi, Matthias; Viana, Blandina F.; Westphal, Catrin; Willcox, Bryony K.; Wratten, Stephen D.; Yoshioka, Akira; Zaragoza-Trello, Carlos; Zhang, Wei; Zou, Yi; Steffan-Dewenter, Ingolf (AAAS, 2019-10)
    Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.
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    Organic farmers face persistent barriers to adopting diversification practices in California's Central Coast
    Carlisle, Liz; Esquivel, Kenzo; Baur, Patrick; Ichikawa, Nina F.; Olimpi, Elissa M.; Ory, Joanna; Waterhouse, Hannah; Iles, Alastair; Karp, Daniel S.; Kremen, Claire; Bowles, Timothy M. (Taylor & Francis, 2022-09-14)
    In the face of myriad environmental challenges associated with industrial agriculture, some farmers and researchers have looked to diversified farming systems as a promising alternative. Despite well-documented ecological benefits, diversification practices remain rare in many regions of the U.S, even amongst organic farmers. Our study focuses on organic farmers in the Central Coast region of California, an area that has played a crucial role in the rise of organic agriculture over the last several decades. Through 20 interviews with farmers who all grow lettuce and 8 interviews with technical assistance providers, we investigate the persistent barriers that growers in this region face in adopting diversification practices including cover cropping, compost application, crop rotation, insectary strips, and hedgerows. We find that high land rents, the predominance of short-term leases, stringent food safety standards, and other supply chain pressures significantly hamper the adoption of diversification practices. In order to surmount these barriers and increase adoption, solutions must be pursued at three interconnected levels: innovation at the farm level, and policy change at the technical and structural levels. Locally-informed, integrated, and innovative policies across these three levels must be explored to support the creation of a more resilient, sustainable, and equitable food system.