湖北林业科技

Abstract:Niche characteristics of main tree species of communities in different regeneration patterns about montane mixed evergreen and deciduous broadleaved forests were analyzed by means of Shannow-wiener niche breadth and Pianka niche overlap indexes.The results showed that different regeneration ratterns have an significant effect on the main tree species niche of montane mixed evergreen and deciduous broadleaved forests.Niche of Sassafras tsumu were the highest in the artificial renewal forests,but they squeezed by the undergrowth of evergreen shrubs,their niche width will be narrowed. Niche of Sassafras tsumu was the third in the artificially-promoted natural regeneration forests by the extrusion of Eurya hebeclados and Eurya brevistyla,and the community has a benign direction of succession.Niche breadth of Carpinus fargesii in upper deciduous trees was the highest in the natural regeneration forests,lower evergreen trees and shrubs occupy a larger niche,the main species niche structure tended to be rational.Niche overlaps of deciduous broadleaved trees Sassafras tsumu and Betula luminifera were larger,which that for evergreen broadleaved trees Cycloblanopsis glauca is just the opposite.Differences of niche breadth and niche overlaps of tree species of communities in different regeneration patterns were caused by the degree of compression and release of nonpurpose tree species niche in the process of anthropogenic interference and the results of the competition for resources between species.The community structure can be optimized through niche regulation between the various species.