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为了解长江上游低山丘陵区不同林龄的马尾松(Pinus massoniana)人工林植物物种多样性与土壤特性的变化特征及其联系,选取不同林龄的马尾松人工林作为研究对象,对林下植物多样性和土壤理化性质进行研究。结果表明:(1)3年生马尾松林下喜光植物较多,随林龄增加人工林郁闭度增大,耐阴植物增多。(2)林下物种丰富度指数中龄林最大,成熟林略有下降但明显高于幼龄林。草本层、灌木层的Simpson指数和Shannon指数随林龄增加均呈现早期波动、中期下降、后期增加的变化趋势。(3)随林龄增加,土壤各理化指标的变化不尽相同,但到成熟林时期,土壤有机质、全氮、全磷含量均有所升高,说明马尾松林到成熟林阶段其土壤肥力状况得到一定的提升。(4)群落演替过程中物种多样性变化与土壤因子存在一定相关性,土壤pH、土壤含水量、全磷与植物多样性的关系最为密切。土壤理化性质影响着物种更新和演替进程,同时林下植物群落的演替导致土壤水分和养分发生变化,使得土壤基质的稳定性提高,为更多物种的生存、定居、生长发育提供良好的条件。
In order to understand the characteristics and relationships of plant species diversity and soil characteristics of different age Pinus massoniana plantations in the hilly area of the upper reaches of the Yangtze River, Pinus massoniana plantations of different ages were selected as research objects, Plant diversity and soil physical and chemical properties of the study. The results showed that: (1) There were more hi-hi plants in the three-year-old Pinus massoniana forest. With increasing age, canopy density increased and shade-tolerant plants increased. (2) Species richness index under forest The middle-aged forest is the largest, while the mature forest is slightly lower but obviously higher than the young forest. The Simpson index and Shannon index of herb layer and shrub layer showed the trend of early fluctuation, mid-term decline and later increase with the increase of forest age. (3) With the increase of forest age, the changes of soil physical and chemical indicators are not the same, but the soil organic matter, total nitrogen and total phosphorus content increased to mature forest period, indicating that the soil fertility status of Pinus massoniana forest to mature forest Get some improvement. (4) The change of species diversity in community succession is related to soil factors. Soil pH, soil water content, total phosphorus and plant diversity have the closest relationship. Soil physical and chemical properties affect the process of species renewal and succession. At the same time, the succession of understory plant communities leads to changes of soil moisture and nutrients, which leads to the improvement of soil matrix stability, and provides better conditions for the survival, settlement and growth of more species condition.