不同更新方式對常綠落葉闊葉混交林跡地主要樹種生態位的影響

湯景明++孫擁康??

摘要：運用Shannowwiener生態位寬度指數和Pianka生態位重疊指數，對常綠落葉闊葉混交林跡地不同更新方式群落主要樹種的生態位特征進行了比較研究。結果表明：不同更新方式對常綠落葉闊葉混交林跡地群落主要樹種生態位有重要影響。人工更新群落中喬木檫木（Sassafras tsumu）雖有最高的生態位，為1748，但已受林下常綠灌木的擠壓，將會變窄。人工促進天然更新群落中檫木生態位為1671，因受微毛柃（Eurya hebeclados）、短柱柃（Eurya brevistyla）等樹種擠壓居第三位，群落已向良性方向演替。天然更新群落中喬木層落葉樹種大穗鵝耳櫪（Carpinus fargesii）最高，為1667，常綠樹種青岡（Cycloblanopsis glauca）的生態位已從人工更新群落中的0.601和人工促進天然更新群落中的1.081上升到1584，群落中的落葉樹種與常綠樹種均較大，群落主要樹種的生態位結構趨于合理。落葉闊葉樹種檫木、光皮樺（Betula luminifera）在天然更新群落中的生態位重疊值較低，分別為0387和0292，而常綠闊葉樹種青岡則相反，在天然更新群落中的生態位重疊值較高，為0.537。不同更新方式群落中樹種生態位寬度及樹種間生態位重疊的差異源于人為干擾過程中對非目的樹種生態位的壓縮與釋放程度以及樹種間對資源競爭的結果。通過樹種間生態位調控可以優化群落結構。

關鍵詞：常綠落葉闊葉混交林；次生林；更新方式；生態位；森林經營

中圖分類號：S757文獻標識碼：A文章編號：1004-3020（2017）04-0001-06

The Effects of Different Regeneration Patterns on the Main

Tree Species Niche of Montane Mixed Evergreen and Deciduous Broadleaved Forests

Tang JingmingSun Yongkang

（Hubei Academy of ForestryWuhan430075）

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 Shannowwiener 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 artificiallypromoted 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 nonpurpose 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.endprint

Key words：montane mixed evergreen and deciduous broadleaved forests；secondary forest；regeneration pattern；niche；forest management

生態位是種群在群落中的時間、空間位置及其功能、作用和地位，反映著種群對環境的適應狀態或對資源的利用程度[1]。……