期刊
BIODIVERSITY AND CONSERVATION
卷 14, 期 5, 页码 1175-1194出版社
SPRINGER
DOI: 10.1007/s10531-004-7841-4
关键词
channel change; flood disturbance; GIS; lower Colorado River; restoration; riparian species diversity
We investigated the influence of channel migration and expansion on riparian plant species diversity along the lower Colorado River near the United States - Mexico border. Using repeat aerial photography in a GIS we identified and classed areas of low, moderate, and high disturbance frequency caused by channel expansion and migration. Replicate vegetation plots (12m x 12 m) were sampled in each of the three disturbance classes. One-way ANOVA was used to test for differences in species richness, species diversity ( using the Shannon - Weiner Index) and overall percent ground cover of plants between the three disturbance classes. Regardless of disturbance class, plots were dominated by trees or shrubs, especially the non-native Tamarix ramosissima, as well as Pluchea sericea, Baccharis salicifolia and Salix goodingii. Clearly woody species constitute the great bulk of overall species richness, percent ground cover, and species diversity (H') in each disturbance group. No overall statistically significant differences were revealed among the disturbance groups for values of species richness, percent ground cover, or the Shannon - Wiener Index, though paired contrasts of means revealed that total percent ground cover on low disturbance plots was significantly higher than on moderately disturbed plots. Spatial and temporal variability in riparian diversity in the study area appears to hinge on factors other than disturbance frequency such as salt or drought stress. Alternately, our results could be interpreted as suggesting that in the presence of intensive flow regulation, disturbance plays a secondary role to ecological stresses, similar to that demonstrated by others. Intentional flood pulses are advocated as a restorative management strategy for improving plant productivity, management of exotic species ( particularly T. ramosissima), and restoration of overall biodiversity.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据