Addressing Biological Linkages with the USDA Long-Term Agroecosystem Research Network.

The US Department of Agriculture Long-Term Agroecosystem Research Network (LTAR), currently comprised of 18 sites across the USA, some croplands and others grasslands, was established to focus on the long-term research essential to understanding how key agricultural system components interact at the whole system level. One fundamental component of the agriculture system is the abundance, diversity, and complex linkages of biodiversity that the system supports, and the values of such biodiversity to society. This paper will introduce how LTAR will address synergies and tradeoffs between agricultural production and biodiversity on the path to sustainable intensification. It will describe how LTAR can capitalize on unique aspects of the network including: systematic tracking of ecosystems over time; standardized approaches to biological data management; embedding biodiversity research into long-term cross-site experiments; drawing from and contributing to long-term global biological datasets; and opportunities to scale from plot, to site, to region, to network. A brief case study will be summarized from the Archbold Biological Station-University of Florida LTAR, located in the subtropical cattle grazing lands of south-central Florida. It will address wetland plants in relation to insect flower-visitors, fire, grazing, nutrients, and wetland restoration and how these processes interact with the presence of an invasive species, feral pigs Sus scrofa, and concomitant implications for agricultural production and disease transmission in grazing landscapes. We will raise questions and suggestions on scaling complex biological linkages from an LTAR site to the entire network. The case study will be the basis for further discussion on how LTAR may help address critical and emerging questions about biological linkages in agroecosystems across the USA.