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天然针叶林在热带地区虽较为少见,但其对维持热带地区的生物多样性和生境异质性具有特殊意义。在我国热带天然针叶林集中分布面积最大的海南霸王岭林区,作者选择伴生阔叶树种优势度不同的两种典型南亚松(Pinus latteri)天然林(简称纯林和混交林),采用点格局法分析了其林冠层、亚林层和林下层主要树种的空间分布格局及其关联性。结果表明:(1)纯林中林冠层的南亚松主要为聚集分布,混交林中在较小尺度上为聚集分布,在较大尺度上为随机分布。(2)纯林中亚林层树种在较小尺度上为聚集分布,在较大尺度上为随机分布,在混交林中主要为聚集分布。(3)纯林中林下层树种主要呈现为随机分布,而在混交林中主要为聚集分布。(4)随着尺度的增加,林冠层与其他两个层次的树种,在纯林中表现出从空间无关联到正关联的变化趋势,而在混交林中则表现出从空间无关联到负关联的变化趋势。(5)亚林层与林下层树种在各个尺度上都表现为空间正关联。由此可见,热带天然针叶林中优势种南亚松对伴生阔叶树种的分布格局具有重要影响。
Although natural coniferous forests are rare in the tropics, they are of special importance for the conservation of biodiversity and habitat heterogeneity in the tropics. In Bawangling, Hainan, the largest area of tropical natural coniferous forest in Hainan, the authors selected two typical Pinus latteri natural forests (referred to as pure forest and mixed forest) with different dominance of broadleaf tree species, Method was used to analyze the spatial distribution pattern and its relationship of the main tree species in the canopy layer, the yarim layer and the subtropical layer. The results showed that: (1) The canopy distribution of South American pine in pure forest was mainly aggregated distribution. In mixed forest, it was aggregated distribution on a smaller scale and distributed randomly on a larger scale. (2) In the pure forest, the species of Arboreal forest is aggregated on a smaller scale, distributed randomly on a larger scale, and mainly distributed on a mixed forest. (3) Pure forest The main tree species in the middle and lower reaches of Zhonglin were randomly distributed, but mainly distributed in the mixed forest. (4) With the increase of scales, the canopy and other two levels of tree species show a trend of non-correlation to positive correlation in pure forests, while in mixed forests they show no correlation from negative to negative Correlation trends. (5) The Yalin layer and the undergrowth tree species appear to be spatially related at all scales. Thus, the dominant species of Pinus taeda in tropical natural coniferous forests have an important impact on the distribution patterns of associated broad-leaved species.