不同立地环境下金沙江干热河谷各区段植物多样性

  目的  为更精准地保护和修复金沙江干热河谷生态环境，明晰不同立地环境下金沙江干热河谷各区段植物多样性结构特征与差异。  方法  采用标准样地调查法调查金沙江干热河谷上段、中段和下段共47个样地的植物物种丰富度和多样性等。  结果  ① 金沙江干热河谷植物丰富度、多样性和均匀度从上段到下段有增加趋势，植物丰富度从大到小依次为天然林(20.56)、人工林(12.16)、稀树灌草丛(8.00)，天然林和人工林之间多样性和均匀度差异均不显著。② 随海拔上升，植物多样性有增加趋势。阴坡植物多样性显著高于阳坡(P＜0.05)。③ 在海拔800~1 400 m，上段、中段和下段多样性差异不显著，而在海拔1 400~2 000 m，多样性从大到小依次为下段、中段、上段；同一坡向下段的植物多样性均高于中段和上段，且下段的Shannon-Wiener多样性指数和Simpson多样性指数显著高于上段(P＜0.05)。  结论  受海拔和坡向等立地环境的影响，金沙江干热河谷各区段植物多样性存在明显差异，局部造林可提高当地的植物多样性。图1表4参27

Plant diversity in various sections of Jinsha River dry-hot valley under different site environments

  Objective  This study is aimed at an investigation of the structural features and differences of the plant diversity in various sections of the dry-hot valley under different site environments so as to efficiently protect and restore the biological environment of Jinsha River dry-hot valley.   Method  With the employment of standard sample plot survey method, a survey was conducted of the plant species richness and diversity of 47 plots in the upper, middle and lower sections of the Jinsha River dry-hot valley.   Result  The plant species richness, diversity and uniformity of the Jinsha River dry-hot valley increased from the upper section to the lower one with the order of species richness being natural forest (20.56)＞plantation (12.16)＞sparse trees and shrubs (8.00) and no significant difference in diversity or uniformity between natural forest and plantation. The plant diversity tends to increase as the altitude increases with the plant diversity of shade slopes being significantly higher than that of sunny slopes (P＜0.05). No significant differences have been found in diversity among the upper, middle and lower sections in the range of 800?1 400 m, while in the range of 1 400?2 000 m, the diversity in the middle section was lower than that in the lower section, but higher than the upper section. The plant diversity in the lower section was always higher than that in the middle section and the upper section of the same slope, and the Shannon-Wiener diversity index and Simpson diversity index in the lower section were significantly different from those of the upper section (P＜ 0.05).   Conclusion  There are significant differences in plant diversity in various sections of the Jinsha River dry-hot valley, with altitude and slope as main environmental influencing factors, and local plantation may increase the plant diversity. [Ch, 1 fig. 4 tab. 27 ref.]