黄土高原马栏林区主要植物种的生态位研究

应用L ev ins、Shannon-W iener生态位宽度公式和P ianka生态位重叠公式,定量研究了黄土高原马栏林区主要植物种的生态位宽度和生态位重叠特征,同时对主要种在演替系列上的生态位变化规律进行了分析.结果表明,在该地区森林群落演替系列中,乔木种生态位宽度的平均水平小于灌木种,建群种的生态位宽度小于主要伴生种;生态位宽度较大的种与其它各物种间生态位重叠的平均值较大,生态位宽度较小的种则相反,甚至没有重叠.由于物种生物生态学特性的不同和环境的异质性,具较宽生态位的物种间的生态位重叠也可能较小,生态位宽度较窄的物种间也可能有较大的生态位重叠,同属植物种对间也存在生态位重叠较大的情况.主要乔木和灌木种的生态位特征反映了森林群落演替的变化规律,该地区呈现出以自然恢复为主,同时又伴随着人为干扰的森林群落次生演替系列.

Niches of Major Plant Species in Malan Forest Standing in the Loess Plateau

Levins's and Shannon-Wiener niche breadth formula and Pianka's niche overlapping formulae are adopted to quantitatively study the niche breadths and overlapping feathers of major plant species in Malan forest standing in the Loess Plateau as well as analyze the niche patterns of these major plant species following their successions.The results showed that in the community successions of the forest,the niche breadths of the arbor species are larger than those of the shrub species on average and the niche breadths of the constructive species are smaller than those of the companion species;the species with large niche breadths present a lager overlap with other species and the species with small niche breadths present an opposite picture,and even no overlap.Because different species have different ecological features and face heterogeneous environments,it is possible for the species with large niche breadths to overlap less and it is possible for the species with small niche breadths to overlap more.The niches of the major arbor and shrub species reflect the succession patterns of forest communities,which show that the region appears to naturally recover but the sere affected by human interferences accompanies.