浙江九龙山常绿阔叶林不同物种的径级结构及空间关联

Size structure and spatial association of different species of an evergreen broad-leaved forest in Jiulong Mountain,Zhejiang Province

【目的】不同植物物种或类群(优势种、常见种、偶见种与稀有种)往往具有不同的生态学特性。通过对不同物种或类群的径级结构和空间格局进行研究,有助于揭示物种共存机制。【方法】基于浙江九龙山国家级自然保护区1 hm2常绿阔叶林长期监测样地,通过点格局分析等方法,对24种植物和不同类群的径级结构以及空间关联性进行分析。【结果】①15种植物以及常见种、偶见种和稀有种为小径级个体居多的“L”型分布,3种植物为单柱型分布,3种植物为间歇型分布,3种植物和优势种的径级结构为近似正态分布;②多数物种(21/24)或类群以聚集分布格局为主,并受到生境异质性的影响;③优势种与偶见种、稀有种均呈负的空间关联,常见种与其他类群以正的空间关联为主,24种植物对其他类群也以正的空间关联为主。【结论】群落中多数物种和类群受到生境异质性的影响,同时生态位分化减弱了物种或类群之间的竞争,在其共存中发挥着重要作用,群落暂时处于一个稳定的状态。图3表3参33。

[Objective]Different plant species and groups,with dominant species,common species,occasional species and rare species included,often demonstrate various ecological characteristics.Therefore,this study,with an investigation of the size structure and spatial pattern of different species and groups,is aimed to further explore mechanisms of species coexistence.[Method]With the long-term monitoring 1 hm2 plot of evergreen broad-leaved forest in Jiulong Mountain National Nature Reserve of Zhejiang Province,China selected as the subject,point pattern analysis was conducted of the size structure of 24 common species and different groups and their association with other groups and habitat factors.[Result](1)The size structure of 15 species and common species,occasional species,and rare species was mainly distributed in an“L”shape with more small-diameter individuals.The size structure of 3 species was distributed in sporadic type and 3 species was distributed in unibar type.The size structure of 3 species and dominant species was close to the normal distribution;(2)The spatial distribution pattern of most species(21 out of 24)or groups was in aggregation and was affected by habitat heterogeneity;(3)Dominant species had negative spatial association with occasional species and rare species,and common species had positive spatial association with other groups whereas the significant spatial associations of 24 common species with other groups were mainly positive.[Conclusion]Most species and groups in the community were affected by habitat heterogeneity.At the same time,niche differentiation weakened the competition between species or groups,playing an important role in their coexistence.The community is temporarily in a stable state.[Ch,3 fig.3 tab.33 ref.]