The Southern Appalachians are ecologically diverse with several distinct ecosystem-types. To better conserve the region's ecological resources and to predict or mitigate the consequences of increasing interaction between these ecosystems and human activities, information regarding the region's ecological resources must be readily available. 

Accordingly, the SAIN geographic perspective within the NBII focuses on identifying and serving biological information relevant to key regional ecosystems, with the aim of fostering informed resource managment and increasing knowledge through collaboration. 

SAIN's initial focus areas include the following ecosystems:

• Mountainous Ecosystems: The portion of the Appalachian range that extends from Pennsylvania's Alleghenies south to Alabama's Red Mountain. SAIN's focus is primarily in the Southern portion of this region.
• Forest Ecosystems: According to the U.S. Fish and Wildlife Service, forest ecosystems occur where the tree canopy covers at least 10 percent of the ground area.
• Aquatic Ecosystems: Rivers, lakes, wetlands, and other water-based ecosystems. In particular: the Tennessee River and its tributaries and the Lower Mississippi River and its tributaries.
• Urban /Wildlands Interfaces: Transition areas for urban, sub-urban, and industrial development with wildlands.
• Agricultural Ecosystems: Agricultural ecological regions are the multiple small-scale agri-ecosystems, which collectively have an impact on the biological resources of the region.