关键词: 蕨类植物, 坡向, 生物多样性, 生态适应性, 指示作用

Abstract

In order to examine the effect of slope differences on fern diversity, we chose 10 plots (5×5 m² for each plot) on east-, west-, south-, and north-facing slopes, with altitudes ranging from 20 to 986 m in Gudoushan Nature Reserve, Xinhui, Guangdong, China. We obtained the following results: (1) Species abundance on the east- and north-facing slopes were high, while that on the west- and south-facing slopes were low. (2) Similarity indices of ferns in different slope orientations were low (<0.5), which suggested that orientation significantly influenced fern diversity. The difference between the south- and north-facing slopes (similarity index, 0.2895) and the similarity between west- and south-facing slopes (similarity indices, up to 0.4643) were the most obvious. (3) Tropical ferns were dominant in sunny slopes, while non-tropical ferns were dominant in shady slopes. The percentage of tropical ferns on the south-, west-, east-, and north-facing slopes decreased, while that of non-tropical ferns increased. (4) Shade ferns were dominant in shady slopes, while sunny ferns were dominant in sunny slopes; the number of shade ferns regularly increased on the south-, west-, east-, and north-facing slopes. These results clearly indicated how light and heat on different slopes affected fern diversity and suggested that fern diversity could be a good indicator of environmental and climatic changes.

Key words: pteridophytes, slope, biodiversity, ecological adaptation, indication