Changes in landscape patterns and associated forest succession on the western slope of the Rocky Mountains, Colorado

Using repeat photography, we conducted a qualitative and quantitative analy sis of changes in forest cover on the western slope of the Rocky Mountains in Colorado. For the quantitative analysis, both images in a pair were clas sified using remote sensing and geographic information system (CIS) technol ogies. Comparisons were made using three landscape metrics: total relative cover, mean relative patch size, and number of patches per major vegetation type. We noted several important changes in the pattern of the landscape a nd the structure of the forests. The relative area covered by interspersed, nonforested rangelands has decreased significantly, and the total forest c over across these landscapes has increased. Statistical analyses (ANOVA) of other landscape characteristics (patch number and patch size distribution) did not detect changes. However, nonstatistical observation of the trends in these data revealed that in many cases, there has been important, observ able change in the configuration of the landscape at many of these location s. Furthermore, our field data show that 96% of the sampled forests have a conifer component in the overstory, understory, or both.