Forecasting landscape change at the ecoregion scale: Interacting threats from cumulative local-scale processes and large-scale development events

Land use change is a dynamic process involving both localized decisions made by individuals and large-scale planning by institutions. Biodiversity conservation on private undeveloped lands increasingly depends on the ability to forecast cumulative changes that result from land-use decisions made by local entities and to anticipate rapid large-scale change. Ecoregions are large-scale conservation planning units with ecological cohesion but frequently encompass heterogeneous human landscapes inclusive of multiple jurisdictions and ownerships displaying both cumulative and instantaneous change of use. Successful planning for biodiversity conservation must anticipate and incorporate temporal and spatial patterns of land-use change at multiple scales. We demonstrate both cumulative and sudden change and their interaction using a spatially explicit forecasting tool (Future Human Footprint), based on the WCS Human Footprint™ methodology for scoring human impact. We use a logit-based forecast of growth of residential public roads to illustrate cumulative effects of local planning decisions in the Northern Appalachian Ecoregion (300,000 km²). To anticipate transition of previously unsettled forests, we developed a risk analysis for amenity development on unprotected lakeshores accessible to urban populations and weighted by ownership category with real-estate driven companies representing higher probability of transition and timber companies lower. Results indicate that cumulative road growth produces a doubling of residential roads over 20 years while ownership-weighted risk to lakeshores introduces a swath of new development across previously unsettled private forestlands. Combining these concurrent processes, the model shows a pattern of settlement that intensifies and expands impact at the local scale while introducing new sprawl centers in remote locations resulting in fragmentation at the ecoregion scale. By integrating different dynamic land use change processes the Future Human Footprint illustrates the need for conservation planning to incorporate multiple forms of threat and for action to occur at multiple scales.