Colorado Statewide Forest Resource Assessment

The second metric is an estimate of both the direct (HMc), and effective orfunctional aspects that are due to visible modifi cations to cover, as well asproximal effects associated with human activities such as lights, noise, sound,pets, etc. These effects typically decline as a function of distance away fromhousing units, roads and other associated infrastructure. This effect is referredto as the human modifi cation function (HMf). We used a distance of 100mradius from each housing unit structure, which others have concluded to berepresentative of general ecological effects.Estimates of HMc and HMf were developed from the interpretation ofhigh-resolution aerial photography from more than 300 randomly located plotsor “chips” throughout the public-private land interface in the southern Rockiesecoregion. Although some regional variation in effects of land use on habitatexists, these estimates provide useful measures of effects and are fairly robustgiven common development patterns. Future research, however, could pursuedevelopment of regionally specifi c estimates.Map 3 – Projected Change in Human Modification from 2000 - 203022