通过杉木采伐迹地撂荒重建乡土维管植物多样性  

Reestablishment of indigenous vascular diversity under fallow blanks of clear cutting Chinese fir plantations in the subtropical region of China.

作　　者：颜绍馗[1] 汪思龙[1] 范冰[1] 李媛良[1] 张代贵[2] 

机构地区：[1]中国科学院沈阳应用生态研究所中国科学院会同森林生态实验站 [2]吉首大学生命科学与环境学院

出　　处：《北京林业大学学报》2007年第6期79-85,共7页Journal of Beijing Forestry University

基　　金：中国科学院知识创新工程重要方向项目(KZCX3-SW-418)

摘　　要：撂荒为采伐迹地树种提供了更新机会,但是撂荒在用材林向天然林转化过程中的作用和机制,尚不清楚.该文比较分析了亚热带湖南会同林区,杉木采伐迹地撂荒10年而成的次生常绿阔叶林、杉木人工林、老龄次生常绿阔叶林,3个演替阶段的维管植物多样性差别.结果显示,撂荒过程相对于杉木人工林过程有显著更高的物种丰富度、Shannon多样性和Sφrensenia相似性距离,但是Pielou均匀度在乔木层、林下层以及各生长习性的比较中表现相似.NMS(非度量多元标度)排序揭示不同的演替阶段,无论乔木、灌木、草本还是藤本均有明显的分组现象,从杉木林林下植被演替到老龄常绿阔叶林,β多样性是增加的.进一步的回归分析检验了灌木、草本和藤本的物种组成单独对树种的更新没有显著的影响,但是其总的联合效应促进了本地树种的更新.实验证实,撂荒所致的物种变化不单纯是α多样性的改变同时还伴随了β多样性的增加,表明撂荒可作为多样性保护及天然林重建的一种手段.Fallow provides an important regeneration chance for many tree species after clear cutting,but its role in the restoration of forest fragments and conversion of timber plantation into continuous nature forest landscape is not clearly documented.To examine the role of fallow in reestablishing native tree diversities and assessing whether fallow can be used as a tool for the fast conversion of plantation to natural forest,the authors compared floristic diversity and community composition of vascular plants in 23 years old Chinese fir（Cunninghamia lanceolate（Lamb.） Hook.） plantations（〉15 hm^2,as the control;A）,10 years old secondary forests（（12 hm^2）,fallowing treatment;B） and two 120 years old matured secondary forests（〉15 hm^2,target;C） in the Huitong of Hunan Province,subtropical part of China.Results indicated that Pielou＇s evenness of plant species among forests was insignificantly different due to the studied parameters such as strata,canopy and understory and four life forms（herb,shrub,tree,and vine）.However,species richness,Shannon diversity and Srensen＇s index of dissimilarity were higher in fallowing immature secondary forest than those of the plantations of Chinese fir.Based on non-metric multidimensional scaling（NMS） ordinations,estimated values revealed clear separation between forest sites in different succession stages at each of four life forms,and further showed a significant effect on understory vegetation of Chinese fir plantations untill to old growth secondary forest,indicating an increasing beta diversity.Although regression analysis exhibited that herbaceous composition（represent by NMS 1 scores） had not affected tree species turnover,but the combined effects of herb with shrub and vine facilitated the regeneration of tree species.Therefore,results evidently indicate that the higher species variability during fallow after clear cutting timber trees is associated not only with the higher alpha diversity but also with the higher beta diversity,and s

关 键 词：人工林 天然林 亚热带 撂荒演替 物种周转 

分 类 号：S718.542[农业科学—林学]