Leads: Drs. Ingolf Steffan-Dewenter (University of Würzburg) and Katja Poveda (Cornell University)

Concept: Land use change threatens the biodiversity and ecosystem services upon which agroecosystems depend. Some agroecological practices may buffer the negative impacts of simplification on biodiversity and ecosystem services.

Objective: To examine and model how agroecological practices, such as legume intercropping, composting and botanical sprays, can buffer against the loss of biodiversity and ecosystem services across multiple scales and under different scenarios of land use change. Identify breakpoints of landscape-level use of agroecological practices above which biodiversity and ecosystem services are maximally retained.

Data Collection:

• Assess biodiversity and ecosystem services on 50 farms, as well as land cover within a 3 km radius of each farm, using participatory methods with team of ecologists, geographers, and trained farmer-researchers. Utilize participatory Geographic Information Systems to collect land cover data.
• Measure multiple dimensions of biodiversity, including taxonomic, functional, and phylogenic diversity of bees, birds, and natural enemies (parasitoid wasps and ground-dwelling arthropod predators). Assess ecosystem services of pest suppression, pollination, and crop yield.
• Survey birds with six point counts per year and capture bees and parasitoid wasp on all farms, during and immediately following the growing season.
• Perform replicated exclosure experiments to measure pollination deficits.
• Measure yield of each field to identify yield gap on farms as compared to maximum tield measured across all farms.

Analysis and Scenario Modeling:

• Use statistical models to determine primary drivers of biodiversity, ecosystem services, and any observed yield gap.
• Determine the land cover around each farm. The amount of agroecological practices will vary across the landscape, allowing us to determine if there are breakpoints in biodiversity and ecosystem service provision based on the proportion of area where agroecological practices are used within multiple scales of each farm.
• Model a range of ten land use change scenarios reflective of realistic rates of change over the next 25 years and assess likely impacts of that change on biodiversity and ecosystem services across the studied region. We will assess how the outcomes change according to the use of agroecological practices in the region, as well as the economic impacts from using these practices.

Expected Results and Use:

• Ten modeled scenarios of land use change over the next 25 years.
• Guidelines to inform policy makers and communities on where breakpoints of biodiversity and ecosystem services likely exist, providing clear recommendations.
• Anticipated minimum of 2 peer-reviewed publications in conservation or ecology journals, 1-2 publications in multidisciplinary journals, and reports prepared for the Government of Malawi.