Category: Ecological Research
Title: Herbaceous and Shrub Communities in Grand Canyon Forests
Author: * Springer, J.D., * Fule, P.Z., * Huisinga, K.D. , Moore, M.M., * Covington, W.W.
Subject: Understory, Species richness, Diversity, Forest structure, Fire ecology, Pre-settlement, Kaibab Plateau, Coconino National Forest, Grand Canyon, Aspen, Mixed conifer, Ponderosa pine (Pinus ponderosa)
Abstract: Understory plant communities were measured at five Grand Canyon National Park study sites and one Kaibab National Forest study site. Average species richness ranged from 6.4 to 19.5; weighted richness (Simpson's Index) ranged from 2.6 to 7. Dense, fire-excluded forest sites on the North Rim had the lowest richness. Cumulative species curves indicated that approximately 50% of species were captured within 10 sampling plots. Forbs and graminoids were the most common growth 'forms at all sites. The proportion of native species ranged from 79% to 98%. Four plant farniliesPoaceae, Asteraceae, Fabaceae, and Schrophulariaceae-predominated. Most grasses were in the C3 ("cool season") category. One invasive exotic grass, Bromus tectorum, was encountered in low frequencies but remains a concern for further spread with fire. Plant community ordination indicated that sites were segregated and two environmental variables, canopy cover and tree basal area, were significantly associated with community trends.
Source: Plant Communities in Grand Canyon Forests
Publisher: Grand Canyon Forest Ecosystem Restoration