Agroforestry systems help achieve food security and higher sustainable yields. These systems also help harvest and conserve ecological resources including water, nutrients, and soil, and contribute to biodiversity conservation, and carbon sequestration. Multistrata agroforestry systems in coffee and cacao are extremely viable in large parts of tropical America. These systems are particularly promising for integrating biodiversity conservation with production goals, given their botanical and structural complexity. Integrating agroforestry into the landscape contributes to the spatial complexity of ecosystems and is a promising avenue for both sustainable production and biodiversity conservation within fragmented, human-dominated landscapes. Silvo-pastoral systems, in which woody perennials are combined with grasses for livestock, hold similar potential for achieving productivity and conserving biodiversity.

Successful, ecologically sound management of pests is essential for sustainable agricultural and forest productivity. In fragmented landscapes, the distribution and movement of potentially beneficial and injurious insects, pathogens, and weedy plant species among and between habitat types can influence pest populations. Natural habitat elements within a landscape can serve as refugia for economically important pollinators, pests, as well as natural enemies of pests. Differential response by pest species and their natural enemies to fragmentation and the scale of fragmentation can influence the dynamics of predator-prey interactions and the efficacy of biological control agents. Levels of disturbance and effects of habitat boundaries, which are much more extensive in fragmented landscapes, can influence the spread of invasive species. Despite progress towards ecologically based pest management, the implications of habitat fragmentation for dynamics of pests and their natural enemies are not clearly understood and require further research.

IGERT student projects in this research area will address questions pertaining to the effects of fragmentation on the management of agricultural and forest systems. Agroforestry questions revolve around the integration and management of woody perennials on the farm and ways in which these perennials can contribute to both sustainable production and biodiversity conservation. Forestry questions focus on the integration of production and biodiversity conservation in old-growth fragments and the restoration of natural forest and its goods and services through secondary succession. Potential research questions include: What are the relationships between farm tree cover (abundance, diversity, spatial arrangement) and farm productivity? How does fragment size and proximity of other habitat types influence the natural tree species composition in secondary forest fragments? What are the implications of edge and area effects of forest fragments and disturbance by timber harvesting for tree community characteristics (structure, composition and dynamics)? What are the implications of oligarchic tree community assemblages for long-term productivity? Questions that could be addressed in the area of pest management include: What are the biological control organisms present in the landscape? How are these influenced by habitat fragmentation, the scale of fragmentation, and the proximity of other habitats? Can management practices across the landscape be identified for promoting biological control? How do fragment size, boundary dimensions and juxtaposition of habitat types affect populations of invasive weedy species in agricultural habitats? What are the plant species composition along edges, within ecotones between habitat fragments? Is a concerted effort to identify and remove invasive species along such interfaces merited to prevent destructive invasions?