林窗对大兴安岭南段杨桦次生林林下物种多样性的影响  

Effects of forest gap on understory species diversity of poplar and birch secondary forests in southern section of the Da Xing’an Mountains

作　　者：刘兵兵 张波 赵鹏武[1,3] 郑欣 周梅 舒洋[1,3] 王媛 LIU Bingbing;ZHANG Bo;ZHAO Pengwu;ZHENG Xin;ZHOU Mei;SHU Yang;WANG Yuan(College of Forestry,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia 010019,China;College of Grassland and Resources and Environment,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia 010019,China;Inner Mongolia Saihanwula Forest Ecosystem National Positioning Research Station,Chifeng,Inner Mongolia 025150,China;Inner Mongolia Hesheng Ecological Science and Technology Rresearch Institute Co.,Ltd.,Hohhot,Inner Mongolia 011517,China;Inner Mongolia Xing’an League Horqin Right Wing Front Banner Forestry Bureau,Xing’an League,Inner Mongolia 137400,China)

机构地区：[1]内蒙古农业大学林学院,内蒙古呼和浩特010019 [2]内蒙古农业大学草原与资源环境学院,内蒙古呼和浩特010019 [3]内蒙古赛罕乌拉森林生态系统国家定位观测研究站,内蒙古赤峰025150 [4]内蒙古和盛生态科技研究院有限公司,内蒙古呼和浩特011517 [5]内蒙古兴安盟科尔沁右翼前旗林业局,内蒙古兴安盟137400

出　　处：《西北农林科技大学学报（自然科学版）》2020年第4期65-74,共10页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(41861005);内蒙古自治区教育厅研究生科研创新资助项目(S2018111997Z)。

摘　　要：【目的】研究杨桦次生林林窗大小对林下植物多样性及更新的影响,为人为近自然模拟林窗干扰更新与森林物种多样性的保护提供参考。【方法】以内蒙古大兴安岭南段杨桦次生林为研究对象,按面积等级选择林窗12个,每个林窗内设置2 m×2 m样方5个,仅调查样方内的乔木幼苗(胸径≤1 cm)和灌木,同时在每个2 m×2 m样方内设置1 m×1 m的草本调查样方1个,另设置相同面积的林内对照样方(CK)12个,以同样的方法进行植被调查。应用Simpson指数、Shannon-Wiener指数、Pielou均匀度指数、Margalef丰富度指数4种多样性指标和Sorensen群落相似系数指标,分析大兴安岭南段杨桦次生林不同面积林窗中物种组成及物种多样性的差异。【结果】不同面积林窗内乔木更新层更新苗密度为8333.67~12833.33株/hm^2,均高于林内8000.67株/hm^2;林窗内物种数为32~39种,均高于林内物种数20种;无论是林窗还是林内,蒙古栎均为乔木更新层先锋物种,重要值为78.57%~96.07%,但是林窗能够促进其他乔木树种的更新能力,出现蒙古栎优势度衰退的现象;林下物种多样性的变化并非与林窗面积正相关,但是对草本和乔木更新层物种多样性影响显著,林窗内草本层多样性指数均大于林内,乔木层Pielou均匀度指数(Ⅰ号林窗除外)、Shannon-Wiener指数、Simpson指数均大于林内,而灌木层各多样性指数仅有Ⅲ号林窗与Ⅳ号林窗均大于林内;不同面积等级林窗内物种数量及相似系数变化不大,分别为25~30和70.42%~78.95%,而与林内的共有种数及相似系数较低,仅为17~20和58.62%~69.23%。【结论】林窗的出现增加了大兴安岭南段植被物种数量及更新苗密度,且使原先锋物种优势度呈现衰退趋势,这在草本及乔木更新层表现尤为明显。【Objective】The effects of size of poplar forests on diversity and regeneration of understory plants were studied to provide reference for artificial near-natural simulation of regeneration disturbance by forest gap and protection of forest species diversity.【Method】The secondary forests of poplar and birch in southern section of the Da Xing’an Mountains in Inner Mongolia was selected and 12 forest saplings were selected according to areas.Five 2 m×2 m squares were set in each forest window.Arbor seedlings with thorax diameter≤1 cm and shrubs were investigated.A 1 m×1 m herb sample was set in each 2 m×2 m square for grass sampling and 12 squares with same area were set for control(CK).The Simpson index,Shannon-Wiener index,Pielou evenness index,Margalef richness index and Sorensen community similarity index were used to analyze the differences in species composition and species diversity among different forest gaps.【Result】The seedling density of regeneration layer of trees in different forest windows was 8333.67-12833.33 plants/hm^2,all were higher than the forest average of 8000.67 plants/hm^2.The number of species in the forest windows was 32-39,higher than the forest average of 20 species.In both forest window and forest,Quercus mongolica was the pioneer species of tree regeneration layer with the important value of 78.57%-96.07%.The forest window promoted the regeneration ability of other tree species and the dominance of Q.mongolica declined.Species diversity changes were not positively related to the forest gap area,but it had great effect on species diversity in grass and updated layer.Forest gap in herb layer had larger diversity index than forest.The Pielou evenness index(except windowⅠ),Shannon-Wiener index and Simpson index in forest windows were greater than the forest,while only diversity index of windowsⅢandⅣin the shrub layer was greater than the forest.The number and similarity coefficient of species in forest windows with different areas changed slightly with ranges of 25

关 键 词：大兴安岭南段 杨桦次生林 林窗 物种多样性 

分 类 号：S718.51[农业科学—林学]