河北太行山低山丘陵区植被恢复过程中物种多样性与土壤养分变化

Species diversity and soil nutrient dynamics along a chronosequence of vegetation restoration in Taihang Mountains hilly region, Hebei Province of North China

采用野外调查与室内试验相结合的方法,以1986年和2008年调查数据为基础,分析了植物组成与种群结构的变化,运用Shannon多样性指数、丰富度指数、Pielou均匀度指数对太行山低山丘陵区植被物种多样性进行分析,并探讨了土壤养分变化及其与植物物种多样性的相关性。结果表明:1)植被恢复22年后,群落结构和物种组成发生了明显的变化,群落逐渐由草本向乔灌木转变,且草本植物的物种数显著减少;2)灌木的盖度和生物量显著增加,引起灌下小环境的改变,使湿生草本植物明显减少,从而导致物种多样性和丰富度指数降低;3)植物物种多样性主要受土壤有机质、全N、全P、全K、全Ca和全Mg含量的影响。封山育林22年以后,群落结构渐趋合理,生物量显著增加,物种多样性有所减少,并且对土壤表层的养分产生了明显的回馈作用。

With the combination of field survey and laboratory analysis, and based on the investi- gation data in 1986 and 2008, this paper analyzed the changes of plant species diversity （ Shan- non index, richness index, and Pielou evenness index） and their relationships with soil nutrient dynamics along the chronosequence of vegetation restoration in Taihang Mountains hilly region, Hebei Province of North China. After the 22 years vegetation restoration, the plant community structure and species composition in the study area had an obvious change. The life form of the community shifted gradually from herbs to trees and shrubs, and the species number of herba- ceous plants had a significant decrease. The coverage and biomass of shrubs increased signifi- cantly, which altered the understory micro-environment, making the wet herbaceous plants have a remarkable decrease and inducing the decrease of species diversity and richness index. The plant species diversity was mainly affected by the contents of soil organic matter, total N, total P, total K, total Ca, and total Mg. After 22 years natural restoration, the plant community structure became more reasonable, biomass increased greatly, and species diversity had somewhat de- crease, with a remarkable feedback to the nutrient contents of soil surface laver.