| 摘要: |
| 【目的】探究人为干扰对川西碧峰峡木荷(Schima superba)次生林群落结构与物种多样性的影响，为碧峰峡景区周边次生林植被恢复和物种多样性保护提供科学依据。【方法】以碧峰峡木荷次生林为研究对象，采用典型样地法，设置12块20 m×30 m的代表性样地，以乔木径级结构、高度级结构及各林层物种组成和物种多样性指数为评价指标，对比研究轻（远离核心景区80～120 m）、中（距离核心景区40～80 m）、重（紧靠核心景区0～40 m）3种人为干扰强度下群落结构和物种多样性的变化。【结果】（1）木荷次生林群落总的物种数随人为干扰强度增加而减少，重度干扰群落组成比轻度干扰下少了26科42属64种。（2）轻度干扰下，木荷次生林群落乔木个体径级呈倒“J”型分布，个体数呈现低高度级>中高度级>高高度级分布，群落天然更新能力强；中度干扰下，乔木个体径级呈正态分布，低、中高度级乔木个体数多，群落稳定；重度干扰下，乔木个体径级呈近似正态分布。（3）木荷在不同强度干扰群落中依旧占据优势地位。重度干扰下，大熊猫主食蓉城竹(Phyllostachys bissetii）濒临消失，该灌木层新出现细叶楠（Phoebe hui）、宜昌润楠（Machilus ichangensis）等乡土树种幼苗，草本层遭到严重破坏。（4）随干扰强度的增加，乔木层、草本层物种丰富度指数和Shannon-Wiener多样性指数值均降低，草本层降幅最大；灌木层各指数值在中度干扰群落中最大，符合中度干扰假说。【结论】重度人为干扰虽一定程度上有利于乡土树种萌发生长，但普遍会引起植物物种多样性消失，群落发展不稳定，不利于植被恢复和物种多样性保护。 |
| 关键词: 人为干扰 木荷次生林 群落结构 物种多样性 川西碧峰峡 |
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| 基金项目:国家自然科学基金项目(31370628)；国家“十二五”科技支撑计划项目(2011BAC09B05)；四川省教育厅一般项目（自然科学）（15ZB0020）；四川农业大学双支计划博士专项基金项目(00370401) |
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| Effects of human disturbance on community structure and species diversity of Schima superba secondary forest in Bifengxia,western Sichuan |
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YAO Xiaolan,HAO Jianfeng,QI Jinqiu,et al
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| Abstract: |
| 【Objective】The community structure, composition and species diversity of Schima superba community were studied to provide scientific basis for the restoration of secondary forest vegetation and conservation of species diversity in Bifengxia scenic area,western Sichuan.【Method】A total of 12 representative sample plots of 20 m×30 m were set using typical sampling method in the Bifengxia S.superba secondary forest.Using diameter class,height class,species composition of each forest layer,species diversity index as indicators,the effects of slight (far from the core scenic area at 80-120 m),medium (distant from the core scenic area at 40-80 m),and severe (close to the core scenic within 40 m) human disturbances on community structure and species diversity in Bifengxia S.superba secondary forest were investigated.【Result】(1) The number of species in the S.superba secondary forest community decreased with the increase of human disturbance and it was reduced by 42 families,26 genera and 64 species in the severe disturbance community comparing with the slight disturbance community.(2) Under slight disturbance,the individual tree diameter class of S.superba secondary forest community conformed an inverse J-shape and the height class was in the order of low height class>medium height class>high height class,which indicated strong capacity of natural regeneration.Under medium disturbance,the diameter class showed normal distribution and the numbers of low and medium height class trees were large,suggesting stable development.Under severe disturbance,the diameter class was in approximate normal distribution.(3)S.superba was dominant under different human disturbances.As the main food of giant panda,Phyllostachys bissetii disappeared under severe interference.Seedlings of local trees including Phoebe hui and Machilus ichangensis appeared in the shrub layer,and the herb layer was severely damaged.(4) The diversity indexes S and H in the tree and herb layers decreased with the increase of human disturbance,and herb layer had the largest decreases.The species diversity indexes in shrub layer were the largest under medium disturbance,in accordance with the “intermediate disturbance hypothesis”.【Conclusion】Although severe disturbance benefits the sprouting and growth of local trees,it leads to decrease of the species diversity and unstable community development,and it is not conducive to the protection of vegetation restoration and species diversity. |
| Key words: human disturbance Schima superba secondary forest community structure species diversity Bifengxia,western sichuan |
