山地常绿落叶阔叶林空间点格局特征

Spatial Point Pattern Characteristics of Mountainous Evergreen and Deciduous Broadleaved Forest

以川西南亚热带常绿落叶阔叶林为对象，在研究区选择代表性地段设立1个100 m×100 m样地，运用样地调查方法，采用传统的罗盘仪对树体的相对空间位置进行定位，应用Ripley’s K函数对不同种群层和树种进行模拟，研究了山地常绿落叶阔叶林的空间格局特征。在0-75 m范围内不同层（全林、H〈10 m层、H≥10 m层）和不同树种的空间点格局呈规则分布且趋于随机分布；杜鹃与柃木种群、杜鹃与青冈种群、杜鹃与楠木种群、杜鹃与槭种群、槭与青冈种群在整个尺度上（75 m以内）表现为空间负关联，但随尺度增加，曲线逐渐趋于下包迹线，空间关联变得很微弱；不同层、不同树种在每个空间格局下都存在多个尺度转折点，表明与林分内部结构和外部环境有密切的关系。

A permanent plot of 100 m×100 m was established to study the structure and function of subtropical mountainous evergreen and deciduous mixed broadleaved forest in the southwestern Sichuan province（102° 50′ E,30° 02′ N）.The relative position of every tree was pinpointed by compass,and spatial point pattern characteristics of the forest were researched by simulation of Ripley’s K function.The results demonstrated that spatial patterns of different layers,including the whole stand,layers of tree H〈10m and H≥10m,and of different tree species followed a regular distribution but tended to become random above the distance scale of 75m.On the scales less than 75 m,strong negative spatial correlations of tree populations were found in Cyclobanlanopsis glauca,Rhododendron spp.,Acer spp.,Phoebe zhennan and Eurya brevistyla.However,as the scales increased beyond certain points,the curve tended to form a lower envelope,and the spatial correlation diminished greatly.Using analysis of Ripley’s K function,inflexions in multiple scales were found in spatial patterns of all different forest layers and tree species,indicating affinities between forest stand structures and exterior conditions.