不同干扰方式对东北山地沼泽土壤肥力的影响

 通过样地法对小浪底水库库区山地生态系统不同群落间的Shannon-Wiener指数(H′)、Simpson指数(D1)、Margalef物种丰富度(D2)、种间相遇概率(P)和Pielou均匀度指数(Jsw)等多样性指数进行研究,利用统计方法分析不同群落的物种多样性指数与其所处环境的关系。结果表明:1)物种多样性指数和丰富度指数与群落类型有密切关系,同一类型的群落中,多样性指数随演替时间表现出复杂的关系;2)土壤含水量对H′、P、Jsw、D1等呈极显著的正相关性,土壤厚度与H′、D1、P呈显著正相关性;多样性指数与坡度无相关性;土壤有机质、速效氮、速效磷等养分指标与多样性指数H′、D1有显著的正相关;3)多样性指数H′与乔木、灌木群落生物量表现为正相关关系,草本群落与D1相关性不显著;4)乔木林群落的恢复时间与Jsw、H′呈正相关关系,其余多样性指数(P、D1、D2)与恢复时间关系不显著(P>0.05);恢复时间每增加10a,群落物种数平均增加约6种;5)物种多样性指数H′与灌木的盖度和高度呈极显著正相关性;有些单优群落随高度增加和盖度提高,多样性指数反而表现出降低;6)草本植物群落的高度和盖度与物种丰富度指数D2与呈显著的负相关关系,与H′相关性不显著。

Effect of disturbances on soil fertility of northeast mountain swamp

Using species diversity indices,including Shannon-Wiener index(H′),Simpson diversity index(D1),the probability of two successive randomly chosen individuals belonging to different species(P),Pielou's evenness index (Jsw),Margalef species richness(D2),the characteristics of species diversity in difference communities was studied by selecting sample sites in hilly areas of Xiaolangdi reservoir.The relationship between species diversity and habitat was analysed using statistical methods.The results showed that: 1)The species diversity and richness had significant correlation with community types.The diversity indices had complex relationship with succession period.2) Some species diversity indices,such as H′,P,Jsw and D1,were always associated with relatively high soil moisture.and others diversity indices H′ and D1 have positively correlation with soil organic matter,available N,available P,However,thickness of soil had a significantly positive correlation with H′,D1 and P.3) The biomass of shrubs and trees had a significantly correlated with H′.There are no relation between D1 and biomass of herbs.4) The vegetation restoration period was positively correlated with species diversity indices Jsw and H′,but not P,D1 and D2.The species numbers increased by six averagely during 10 years of vegetation restoration.5) H′ had significantly positive correlation with coverage and height of shrubs.Therefore,the diversity indices in some communities decreased with increasing of coverage and height of community. 6)There was a clear negative correlation between species richness indices and height and coverage of herbs,and no significant correlation with H′.