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以湖北省浠水县为例,采用以空间系列替代时间系列的方法,选取长江中游黄壤低丘区不同程度退化植被类型如天然林(石栎)、人工林(杉木、马尾松、毛竹)、灌丛次生林等,以荒裸地为对照,开展植物群落结构、生产力及功能退化特征对比研究。结果表明:(1)退化植被的群落外貌特征为群落层次减少,荒裸地和灌草地都缺乏乔木层,群落内多是阳性喜光植物;林分郁闭度降低,植被覆盖率降低。(2)随着植被退化程度的加深,生物多样性Shannon-Wiener指数的变化趋势为由小到大再变小,均匀度指数Simpson的变化趋势为由大变小再变大。(3)就土壤容重而言,石栎林<杉木林<灌草地<荒裸地,土壤孔隙度状况为马尾松林>灌草林>石栎林>荒裸地,不同退化程度森林类型土壤含水量、最大持水量、最小持水量变化趋势均为马尾松林土壤水分状况最好,其次是灌草林,然后石栎林、杉木林、毛竹林差别不大,荒裸地最差。(4)植被的退化影响土壤养分含量变化,本次调查中,荒裸地的土壤有机质含量为0.97%、全氮含量为0.06%,均明显低于其他森林生态系统,而全钾和全磷含量较为稳定。
Taking Xishui County in Hubei Province as an example, we selected natural forest (Lithocarpus glauca), plantation (Cunninghamia lanceolata, Pinus massoniana, Phyllostachys pubescens) with different series of spatial series instead of time series, Shrub secondary forest, with bare land as a control, to carry out comparative study of plant community structure, productivity and functional degradation characteristics. The results showed that: (1) The community appearance of degraded vegetation decreased in the community level, the arbor layer was absent in the bare land and the shrub-grassland, and the positive hippocampus was mostly in the community; the canopy density decreased and the vegetation coverage decreased. (2) With the deepening of vegetation degeneration, the Shannon-Wiener index of biodiversity changed from small to large and then decreased. The trend of evenness index Simpson changed from big to small and then to big. (3) In terms of soil bulk density, the stone forest (Cunninghamia lanceolata bare soil, the soil porosity is Pinus massoniana forest> Shrubbery forest> Stone oak forest> bare land, The change trend of water volume, maximum water holding capacity and minimum water holding capacity of P. massoniana was the best, followed by shrubs and shrubs, then the stone oak forest, Chinese fir forest, and Moso bamboo forest were not significantly different, but the bare land was the worst. (4) The degradation of vegetation affects the change of soil nutrient content. In this survey, the content of soil organic matter in the bare land is 0.97% and the total nitrogen content is 0.06%, which are obviously lower than other forest ecosystems. However, total potassium and total phosphorus The content is more stable.