鹞落坪落叶阔叶林蔷薇科主要树种的空间分布格局及种间关联性

为探讨大别山森林群落的构建和演替机制, 本文基于安徽鹞落坪落叶阔叶林11.56 ha动态监测样地的定位监测资料, 采用最近邻分析和O-ring函数、Monte Carlo拟合和零模型选取的方法, 分析了落叶阔叶林蔷薇科主要树种水榆花楸(Sorbus alnifolia)、山樱花(Cerasus serrulata)和中华石楠(Photinia beauverdiana)不同年龄阶段的空间分布格局及种间关联性。结果表明: (1)在整个样地中3个树种的小树和成年树阶段都为聚集分布, 且随年龄增加聚集性减弱, 在老树阶段转为随机和均匀分布。(2)在0-50 m尺度范围内, 以完全随机模型(complete spatial randomness, CSR)为零假设时, 3个树种整体及小树都在小尺度(≤ 10 m)上呈聚集分布, 成年树与老树多为随机分布。以异质性泊松模型(heterogeneous Poisson, HP)为零假设时, 树种的聚集与生境异质性间呈负相关, 3个树种只在≤ 4 m尺度上出现聚集现象。(3) 3个树种种内各个年龄段之间在较大范围内多为负相关和无显著相关性, 同时各树种及不同年龄段之间受种间竞争和密度制约效应影响在小尺度上(≤ 10 m)多为负相关, 随尺度增加相关性减弱。综合而言, 大别山落叶阔叶林中蔷薇科植物的分布格局整体上多为聚集分布, 随树龄增加聚集性减弱, 在中大尺度上受生境异质性效应的影响显著, 在小尺度上多为负相关, 各树种内部各龄级相互之间也多为负相关。

Spatial distribution pattern and interspecific correlation analysis of main species of Rosaceae in a deciduous broad-leaved forest in Yaoluoping

In order to discuss community construction and succession mechanism in Dabie Mountains, three main species of the Rosaceae in the Yaoluoping National Nature Reserve were taken as the object of study by using nearest-neighbor analysis and different zero models. An 11.56 ha forest dynamic plot was established in the Yaoluoping National Nature Reserve according to CTFS technical standards. Sorbus alnifolia, Cerasus serrulata and Photinia chinensis were the three most abundant tree species. The three species were divided into three age groups: small tree, adult tree and old tree according to DBH frequency distributions. Based on nearest neighbor analysis, O-ring functions, Monte Carlo fitting and zero model selection, spatial distribution patterns and interspecific correlations of the three main species were analyzed and compared. This study found three major conclusions: (1) The three species were aggregated across all age stages, although aggregation weakened with increasing age. (2) In the DBH range of 0-50 m, trees of the three species were clustered on small scales (≤ 10 m), while adults and older trees were mostly randomly distributed. Additionally, habitat heterogeneity decreased tree aggregation and tree species aggregate on smaller scales (≤ 4 m). (3) Most of the three species were negatively correlated or not significantly correlated with other age groups. Competitive and density-dependent effects seemed to impact species negatively on a small scale as well (≤ 10 m), though correlation decreased with scale. In conclusion, Rosaceae plants in the deciduous broad-leaved forests of Dabie Mountains are mostly aggregately distributed depending on tree age, though habitat heterogeneity impacts aggregation.