三峡水库消落带植物群落组成及物种多样性

研究消落带植物群落多样性的梯度变化和空间分布特征,可为认识和保护消落带生物多样性提供依据。通过对三峡库区澎溪河开县段的植被样方调查,研究消落带植物群落物种多样性的梯度变化和空间分布特征。结果表明:(1)各群落优势种和伴生种的种类和优势度等组成特征变化明显;(2)群落物种丰富度随高程增加而呈先升后降的格局;(3)α多样性与β多样性起伏较大,其中Shannon多样性和Simpson优势度的变化格局相反,其沿高程的曲线变化分别呈M和W型,Pielou均匀度的变化格局基本与丰富度一致,呈先升后降的趋势;相异性指数和Cody指数呈先降后升的格局,最小值均出现在中间高程,最大值出现在较高高程。分析认为,消落带α多样性的变化来自于高程差异造成的淹水时间的差异而导致的生境差异;β多样性变化原因较为复杂,需进一步研究。

Floristic composition and species diversity of plant communities along an environment gradient in drawdown area of Three Gorges Reservoir after its initial impounding to the water level of 156 m

Aimed to provide scientific basis for understanding and maintaining the biodiversity in water level fluctuation littoral zone,the Kaixian reach of Pengxihe River was chosen to study the spatial pattern and gradient variation of plant communities in the drawdown area of Three Gorges Reservoir. In the study area,there was an obvious variation in the kind and dominance of dominant and companion species in each plant community. With increasing elevation,the total species richness decreased after an initial incr...