The future of terrestrial species will largely depend on their ability to persist in working landscapes. Agriculture now occupies ~50% of Earth’s land surface, yet biologists and conservation managers often overlook opportunities for pursing wildlife conservation in farming landscapes. Our research has documented that tropical diversified farming systems— with high crop diversity and patches of native vegetation— can sustain remarkable concentrations of biodiversity (Fig. 1). Using a 12-yr dataset of 120,000 bird encounters across 487 species in four regions of Costa Rica, we showed that tropical bird communities were more resilient and stable in diversified farms than in intensive monocultures (Karp et al. 2011 PNAS). We also found that diversified farms hosted nearly double the number of species as monocultures, while still maintaining community turnover (β-diversity) on par with native forest (Karp et al. 2012 Ecology Letters). In contrast, monocultures homogenized biodiversity through simplifying vegetation structure and favoring a limited set of closely related species. High extirpation rates of evolutionarily distinct birds caused phylogenetic diversity to plummet in monocultures (Frishkoff*, Karp* et al. 2014 Science). Diversified farms, however, housed ~600 million more years of evolutionary history than monocultures. 

Fig. 1: Diversified farms maintain high avian alpha-diversity (Karp et al. 2011 PNAS), beta-diversity (Karp et al. 2012 Ecology Letters), and phylogenetic diversity (Frishkoff*, Karp* et al. 2014 Science).

Diversity Figures

Our recent data suggests that bird species with ranges encompassing dry macroclimates are best equipped to occupy agriculture (Frishkoff et al. 2016). This indicates that climate-change induced drying may favor agricultural birds and homogenize biodiversity at large scales. Thus, existing ideas about land-use change impacts may not be valid under changing climates. Our ongoing work in Costa Rican farming systems centers on investigating the combined impacts of climate-change induced drying and habitat conversion to agriculture on tropical bird communities. Which species will persist in the face of these global changes will depend on both attributes of species (e.g., their functional traits) and the environment (e.g., key niche axes). Our work seeks to identify traits that structure bird responses to independent agricultural and precipitation gradients in the Guanacaste region of Costa Rica and evaluate how nest predation, food resources, and nesting and foraging sites shift along these same gradients. These data and analyses will be used to build multi-species models that predict bird community responses to climate drying and land-use change. Combining these models with alternative climate and land-use scenarios, we will forecast changes bird communities and identify forward-thinking strategies for conserving Neotropical birds.

Publications

  1. Frishkoff, L.O., D.S. Karp, J.R. Flanders, J. Zook, E.A. Hadly, G.C. Daily, and L.K. M’Gonigle. (2016) Climate and land-use change interact synergistically by favoring the same species. Ecology Letters  19: 1081-1090
  2. Wood, S., D.S. Karp, F. DeClerke, C. Kremen, S. Naeem, and C. Palm (2015) A functional trait approach for understanding the impacts of biodiversity in agriculture. Trends in Ecology and Evolution 30: 531-539.
  3. Frishkoff, L.*, D.S. Karp*, C.D. Mendenhall, L. M’Gonigle, C. Kremen, E.A. Hadly, and G.C. Daily. (2014) Loss of avian phylogenetic diversity in Neotropical agricultural systems. Science 345: 1343-1346. *= shared first authorship
  4. Mendenhall, C.D., D.S. Karp, C.F.J. Meyer, E.A. Hadly, and G.C. Daily. (2014) Predicting biodiversity change and averting collapse in agricultural landscapes. Nature 509: 213-217.
  5. Karp, D.S., A.J. Rominger, J. Zook, J. Ranganathan, P.R. Ehrlich, and G.C. Daily (2012) Intensive agriculture erodes b-diversity at large scales. Ecology Letters 15: 963-970. Faculty of 1000.
  6. Karp, D.S., G. Ziv, J. Zook, P.R. Ehrlich, and G.C. Daily (2011) Resilience and stability in bird guilds across tropical countryside. Proceedings of the National Academy of Sciences 108: 21134-21139.

News Coverage

Cool Green Science, EcoAgricultural Partners 1, EcoAgricultural Partners 2GreenwireNature NewsSciDev.Net, The Scientist, Stanford Report 1, Stanford Report 2, Stanford Report 3, Stanford Report 4Tico TimesVice