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以共和盆地乌柳人工林为对象,调查了不同发育阶段(4、11、25和37年生)乌柳林下植物物种组成及物种多样性变化。结果表明,菊科、藜科、豆科和禾本科为各阶段乌柳林下植被的优势科。4个林龄乌柳林下植被重要值较大的物种不尽相同,赖草在各林龄乌柳林下植被中均为优势种。演替各阶段多年生植物种数占绝对优势且基本保持稳定,其单种重要值明显大于一年生植物。随着林龄的增加,在流动、半流动沙地中出现的一年生植物逐渐消失,小、半灌木开始出现在林下植被中。林下植被的地上生物量和盖度均表现为先增加、后降低、再增加的趋势。物种丰富度、物种多样性、均匀度、生态优势度指数均表现为逐渐增加的趋势。随演替进展,林下植被群落结构趋于复杂、稳定,物种多样性达到了较高的水平,植被群落得到了较好的恢复。
Taking the Salix plantation of the Republican Basin as an example, the species composition and species diversity of Ulva Linnaeus at different developmental stages (4, 11, 25 and 37 years old) were investigated. The results showed that Asteraceae, Chenopodiaceae, Leguminosae and Poaceae were the dominant families in the subsoil of Ulva Linnaea. The four species with significant values of the lower stands of Ulva Linnaeus differed in their stand age, and Leyla was the dominant species in the stands of Ulva stand. The succession of perennial species in each stage accounted for absolute advantage and remained stable, the single significant value was significantly larger than annual plants. With the increase of age, the annual plants that appear in the mobile and semi-floating sandland gradually disappear, and the small and semi-shrubs begin to appear in the undergrowth vegetation. Aboveground biomass and coverage of undergrowth showed the tendency of increasing first, then decreasing and then increasing. Species richness, species diversity, evenness and ecological dominance index all showed a gradual increase trend. With the progress of succession, the structure of forest community vegetation tends to be complex and stable, the species diversity has reached a higher level, and vegetation communities have been well restored.