More than half the land mass in the lower 48 states is occupied by croplands and grazing lands. Beyond the boundaries of parks and protected areas, much of the nation’s biodiversity is supported on these working lands. The emerging USDA LTAR network provides a multi-site national-scale window into biodiversity on the nation’s agroecosystems. In terms of biodiversity, the LTAR network ranges from sites with high intensity crop production and a diminution of biodiversity, to native rangelands with rich plant, bird, and predator communities. This presentation will focus on case studies from within LTAR that examine tradeoffs and synergies between production and biodiversity. Given strong public interest, biodiversity research is important for LTAR’s agricultural and public stakeholders.
Four biodiversity monitoring protocols (Soil Microbes, Plant Diversity, Landbird Diversity, Inverts/Pollinators) were initially proposed by LTAR’s Biodiversity Working Group. Network-wide implementation has been limited to date (see other session presentations): grassland sites with richer biodiversity have participated; cropland sites with limited biodiversity and with needs for staff with biodiversity ID skills, less so.
The Archbold UF LTAR at Buck Island Ranch is one site with a rich biodiversity inventory: we present a case study from this site to illustrate one biodiversity tradeoff/synergy approach. A public payment for ecosystem services (water retention to reduce downstream flow and nutrient loading) exhibited synergies between enhanced hydrology and increased biodiversity (native plants, aquatic invertebrates, fish, and frogs), and a tradeoff with reduced forage that was offset by conservation payments. A DSS was used to evaluate priorities for landowners and other stakeholders.
Results/Conclusions
Challenging LTAR biodiversity monitoring and network comparisons is landscape heterogeneity. Biodiversity on production lands may be strongly coupled with embedded natural areas such as riverine systems, wetlands or small woodlots. We present a regional study from the southeastern US that examines biodiversity, production and other ecosystem measures, in relation to the increasing proportion and decreasing fragmentation (increased mesh size) of landscapes that includes both natural areas and low intensity agriculture. This study suggests ways in which biodiversity questions could be scaled across LTAR.
We conclude with a conceptual model that addresses the confluence of production, biodiversity and other ecosystem processes along a continuum of agricultural intensification. It touches on the human dimensions of biodiversity policies, regulations, and payments and their effects on rural prosperity. This offers a path forward for biodiversity research across LTAR.