A Reexamination of the Origin of Forest Differences at a Subalpine Location in Colorado

Abstract

Baker (1991) proposed that forest differences observed on either side of a fence were attributable to differences in grazing. The study location is in a subalpine forest on the Pike National Forest adjacent to the fenced boundary of Colorado Springs watershed land. Grazing on the watershed land has been excluded for over a century, and U.S. Forest Service land has had moderate grazing over the same time period. The Forest Service land supports a relatively dense forest comprised primarily of Piims aristata. The watershed land has a less dense cover composed primarily of Picea engelmcnmii. Baker (1991) attributed vegetation differences to differential grazing pressure. Additional information suggests an alternate explanation for the vegetation characteristics of this site. In the 1930's, the Forest Service began a program of monitoring areas where trees had been planted or where forest health was a concern. Included in these photographic records is a 1960 photograph of the study area that documents the differences in forest type and cover are related to tree planting activities on the Forest Service side of the fence. The evidence that these trees are planted is based on the linear pattern of trees and a general map that shows where tree planting was done.