关键词: Phyllostachys edulis, 生物入侵, 植物多样性, 动态变化, 自然保护区

Abstract

Moso bamboo (Phyllostachys edulis) is an economically important plant, widely cultivated not only for its delicious shoots and versatile culms, but also as an important biomass resource in southern China. However, with its robust growth and strong rhizomes, it has recently been shown to be a problem tree, capable of dominating some forest stands. Indeed, it may displace species within the community it invades with considerable potential impacts. However, little is known about the consequences of its invasion on plant community composition. We compared plant biodiversity change in different communities where we monitored and removed bamboo over a seven years period (2005 to 2011) in Tianmu Mountain Nature Reserve, so as to elucidate the impacts of Moso bamboo invasion. The results showed that Moso bamboo invasion had negative effects on plant communities. Simpson’s Diversity Index in tree and shrub layers of bamboo forest was lower than that of forests consisting of needle and broad-leaved species, and also those containing a mixture of bamboo with needle and broad-leaved plants. However, Simpson’s Diversity Index in the herb layer of bamboo forest was higher than that in the two other forest types. Plant species richness, Simpson’s Diversity Index, and Pielou’s Eveness Index varied greatly among the different forest types over time. In the tree and shrub layers of forests containing bamboo growing with both needle and broad-leaved species, these three indices declined significantly over the monitoring period (P<0.05). In contrast, no significant changes of Simpson’s Diversity Index and Pielou’s Eveness Index were exhibited in either forests containing a mixture of needle and broad-leaved plants or in pure bamboo forest (P>0.05). Plant species richness increased in the herb layer of forests containing bamboo mixed with needle and broad-leaved species, while Simpson’s Diversity Index and Pielou’s Eveness Index did not change greatly over time. The removal of Moso bamboo resulted in an increase in plant species richness and Simpson’s Diversity Index in the tree and shrub layers. In contrast, plant species richness, Simpson’s Diversity Index, and Pielou’s Eveness Index decreased significantly in the herb layer. In summary, in the Tianmu Mountain Nature Reserve, Moso bamboo invasion was found to cause substantial changes in plant species diversity and had strong negative effects on plant communities. These results suggest that, in addition to scientific management, removal of Moso bamboo may be required to restore plant species diversity in these communities.

Key words: Phyllostachys edulis, biological invasions, plant diversity, dynamic changes, nature reserve