茂兰喀斯特森林林隙主要树种的高度生态位

对茂兰自然保护区中喀斯特森林林隙内外主要树种的生态位宽度和生态位重叠进行了研究。结果表明:椤木石楠和巴东荚蒾在林隙内外都占有较高的生态位宽度;生物学特性和生态学特性接近的树种高度生态位重叠较大,反之则较小;云贵鹅耳枥和翅荚香槐的高度生态位重叠在林隙内和非林隙中均较大;在林隙内,光叶榉和圆叶乌桕的高度生态位重叠值最大,而椤木石楠和多脉榆、光叶榉,多脉榆和巴东荚蒾的高度生态位重叠较小;在非林隙内,云贵鹅耳枥和翅荚香槐的高度生态位重叠最大,椤木石楠和多脉榆、光叶榉的高度生态位重叠最小。林隙的存在,削弱了个体生态位重叠值较大的树种间的种间竞争,同时也增强了个体生态位重叠值较小的树种间的种间竞争,从而使森林中物种多样性得以维持。

Height niche of main tree species in gaps in karst forest in Maolan Nature Reserve

The height niche breadth and overlap of main tree species in gaps and non-gaps in the karst forest in Maolan Nature Reserve were studied. The results showed that the height niche breadth of Photinia davidsoniae and Viburnum henryi in gaps and in non-gaps were the biggest. The height niche overlapv was greater between those species with similar biological and ecological characteristics, and vice versa. The height niche overlap between Carpinus pubescens and Cladrastis platycarpa was greater both in gaps and non-gaps. In gaps, the height niche overlap between Zelkova serata and Sapiurn rotundifolium was the biggest, and was comparatively small between Photinia davidsoniae and Ulmus castaneifolia, Photinia davidsoniae and Zelkova serata, Ulmus castaneifolia and Viburnum henryi. While in non-gaps, the height niche overlap between Carpinus pubescens and Cladrastis platycarpa was the biggest, and was comparatively small between Photinia davidsoniae and Ulmus castaneifolia, Photinia davidsoniae and Zelkova serata. Species competition due to the large height niche overlaps is reduced by gaps, while that due to the small height niche overlaps is increased by them, so as to maintain biodiversity in karst forest.