The Human Footprint is a relative measure of human impact - relative to the ecological context. The Human Footprint is calculated by normalizing the Human Influence Index (HII) within ecological subunits within the study area using the equation HFi = [(HIIi - HIImin_j) * 100] / (HIImax_j - HIImin_j) where i represents the cell and j represents the ecologic subunit of which the cell is a member.
Specifically, the Current Trends FHF casts forward these dyanamic components by 1) an exponential growth model for human population based on 1990's county level growth rates acting as a neighborhood effect on 2000-2001 census units; 2) applying a logit model to explain historical changes in road distribution and then project them to the ecoregion scale (Baldwin et al. 2007), and 3) applying a spatial screening model to identify at risk lakeshores, based on protection level, size of lake, distance to nearest urban area, and predisposition of owners to sell. The Current Trends Human Footprint is based on the following scenario:
The Current Human Footprint is based on the following conditions:
Current Trends: under current trends, the rates of change in human settlement experienced during the 1990's continue to drive new settlement patterns into the future (Process 1). Coupled with this is a modest rise in wilderness development around heretofore undeveloped lakeshores - "instantaneous transition" of forested landscapes to developed ones (Process 2).
Process 1: (a) current trends of population growth projected 40 years (b) projected 80% probability surface for regular, public roads
Process 2: ownership-weighted risk to wilderness lakeshores, within 100km from major urban areas
Baldwin, R. F., S. C. Trombulak, M. G. Anderson, and G. Woolmer. 2007. Projecting transition probabilities for regular public roads at the ecoregion scale: a Northern Appalachian/Acadian case study. Landscape and Urban Planning 80:404-411.
Baldwin, R.F. and S. Trombulak. In Revision. Anticipating habitat conversion in unsettled landscapes: a screening model for lakeshores in the Northern Appalachian/Acadian ecoregion. Landscape and Urban Planning.
Sanderson, E. W., M. Jaiteh, M. A. Levy, K. H. Redford, A. V. Wannebo, and G. Woolmer. 2002. The human footprint and the last of the wild. Bioscience 52:891-904.
Project Collaborators:
Stephen C. Trombulak - Middlebury College Gillian Woolmer - Wildlife Conservation Society Canada Justina C. Ray - Wildlife Conservation Society Canada Karen Beazley - Dalhousie University, Canada Conrad Reining - The Wildlands Project, VT, USA Mark Anderson - The Nature Conservancy, USA Graham Forbes - University of New Brunswick, Canada Eric W. Sanderson - Wildlife Conservation Society
Because of the assumptions inherent in scenario modeling, these data should not be used without a thorough understanding of how they were produced. This understand may be obtained by (a) contacting the author (see contact information), or (b) reading and citing peer reviewed literature in which these data are used (published, in revision, or in review). Use for research intended for peer reviewed publication should involve consultation and/or collaboration with the author (s).