We examined the niche characteristics and interspecific covariant relationship of main species in Phyllostachys edulis-Alsophila spinulosa association in Chishui A. spinulosa National Nature Reserve under P. edulis disturbance condition, and analyzed the mechanism of competition and coexistence across different species. The results showed that there were 67 species from 53 genera and 40 families in the association. The importance values, Shannon niche breadth index (BS), and Levins niche breadth index (BL) of P. edulis were the largest, indicating its absolute dominant status in association. The importance value and BL of A. spinulosa ranked the second, while BS was the third. There were 190 pairs of 20 main species. The niche overlap between P. edulis and A. spinulosa was the largest, with niche overlap value of 0.64. 71.6% of species pairs had niche overlap of less than 0.2, indicating low niche overlap and high degree of niche differentiation among species. The overall association of main species in association was significantly positive, and the community was relatively stable. The correlation among the main species was not significant, the linkage was not strong, and the species were independent from each other. P. edulis showed significant positive correlation with A. spinulosa, Brassaiopsis glomerulata, Ficus virens, and Mallotus barbatus, while P. edulis showed significant negative correlation with Mallotus philippensis, Cinnamomum glanduliferum, and Machilus gamblei. Niche difference and fitness between P. edulis and natives affected the coexistence and competition among species. Controlling the expansion of P. edulis and limiting the size of species with negative correlation with A. spinulosa could create a favorable living environment for A. spinulosa.
研究毛竹干扰状态下赤水桫椤国家级自然保护区毛竹-桫椤群丛主要物种的生态位特征和种间协变关系,分析物种间竞争共存机制。结果表明: 群丛中木本及高大草本植物共有67种,隶属于40科53属。毛竹的重要值、Shannon生态位宽度指数(BS)、Levins生态位宽度指数(BL)均最大,毛竹为群丛中绝对优势种;桫椤的重要值和BL值位列第二,BS值位列第三。20个主要物种组成的190组种对中,毛竹与桫椤生态位重叠值最大,为0.64;136组种对生态位重叠值小于0.2(占总对数的71.6%),物种间生态位重叠程度低,生态位分化程度较大。主要物种间的总体联结呈显著正联结,群落相对稳定;主要物种间相关性不显著,联结性不强,种间独立性较强。毛竹与桫椤、罗伞、绿叶黄葛树、毛桐呈极显著正协变,毛竹与粗糠柴、云南樟、黄心树呈极显著负协变。毛竹与土著种的适合度差异和生态位差异共同影响群丛物种间的共存和竞争。控制毛竹扩张,限制与桫椤呈负协变关系物种的规模,可为桫椤营造良好的生存环境。.
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