山东蒙山植物多样性及其海拔梯度格局

2007年7月和2008年7月,采用典型取样法,沿海拔梯度对蒙山自然植被进行调查,发现区域地带性植被为麻栎(Quercus acutissima)林,主要植被类型为麻栎群落、赤松(Pinus densiflora)群落、油松(Pinus tabuliformis)群落、日本落叶松(Larix kaempferi)群落、黑松(Pinus thunbergii)群落和刺槐-麻栎(Robinia pseudoacacia-Q.acutissima)群落,麻栎群落略占优势,已具备继续向温带落叶阔叶林演替的条件基础.蒙山各层次植物物种丰富度呈现出草本层>灌木层>乔木层特征,Shannon-Wiener多样性指数和Simpson多样性指数整体规律为灌木层>草本层>乔木层.以蒙山森林群落不同层次的各种物种多样性指数和森林群落总体重要值为测度指标,均判断蒙山植被演替正处于亚顶极群落阶段.蒙山植物多样性沿海拔梯度呈现出近似中海拔高的单峰格局,这除受温度、湿度、人为干扰与面积外,蒙山植被亚顶极群落演替现状与所调查区域仅有800 m的海拔梯度也是重要影响因素.

Plant diversity and its elevational gradient patterns in Mengshan Mountain, Shandong, China

Samplings were gathered and examined in forests along topographical gradients of Mengshan Mountain, China in July of 2007 and 2008. The major communities in the forests can be classified as Quercus acutissima, Pinus densiflora, Pinus tabuliformis, Larix kaempferi, Pinus thunbergii and Robinia pseudoacacia-Q.acutissima community. Our research suggests that the Quercus acutissima community appears to be a dominant community in a successional stage toward temperate deciduous broad-leaved forests. The species richness in different layers of these communities can be distinguished as, herb layer>shrub layer>tree layer. Both the Shannon-Wiener diversity index and Simpson diversity index were found as shrub layer>herb layer>tree layer. The species diversity indices of different layers and overall importance value of the forest communities indicate that the forests appear to be successional and sub-climax communities in Mengshan Mountain. Our research also suggests that there is a peak with higher species diversity index in the communities of middle elevation. We found that the pattern could be affected by temperature, moisture, and human disturbance. The pattern could also be influenced by the nature of successional stages and sub-climax communities, or it could simply be due to the limitation in our sampling area and extend of gradients (800 m).