The cumulative effects problem in natural resource management and land
use planning stems from the difficulty of demonstrating that while ea
ch single land use change results in a negligible impact, the accumula
tion of these individual changes over time and within a landscape or r
egion may constitute a major impact. This paper details a general appr
oach to estimate the cumulative effects of land use change on wildlife
habitat using Summit County, CO, USA as a case study. Our approach is
based on a functional relationship between effect on habitat and dist
ance from development. Within this building-effect distance, habitat i
s assumed to be degraded, producing a disturbance zone. We sum the tot
al area within the disturbance zone and track how it changes over time
and in response to different land use planning actions. This method i
s sensitive to both housing density and spatial pattern, so that the r
elative effects of clustered development can be evaluated. Two factors
are important in understanding how development potentially degrades h
abitat: alteration of habitat near buildings and roads and landscape f
ragmentation. Our results show clustered development reduces the negat
ive impacts on wildlife habitat. For large building-effect distances,
spatial pattern was found to be a stronger indicator of disturbance th
an density. Efforts to decrease habitat disturbance by lowering develo
pment density should include the regulation of subdivision pattern in
addition to decreasing density. (C) 1997 Elsevier Science B.V.