摘要
森林结构和地形是森林生态系统最明显的特点,也是影响林下幼苗存活和物种多样性的关键因子。该研究采用半球面摄影方法提取八大公山生长监测样地(共1.2 hm2)林冠结构参数,通过调查地表层木本植物幼苗的组成和多度,获取常见植物幼苗叶片功能性状,结合详细的地形信息,利用空间同步自回归模型探究林冠结构变量及地形因子对幼苗物种多样性及功能多样性的影响。结果表明:(1)八大公山亚热带山地常绿落叶阔叶林林冠结构复杂度较高,最大林冠高的平均值达到19.94 m,叶面积指数、平均叶倾角和林冠覆盖度分别为2.94、30.88°和0.87;(2)林冠结构变量和地形因子能够解释32.6%~48.4%的林下幼苗物种多样性指数变异和28.5%~70.2%的功能多样性变异,但地形因子对幼苗物种多样性的影响很小;(3)预测在亚热带常绿落叶阔叶林高海拔的山坡上,有较低的叶面积指数和平均叶倾角群落有较高的幼苗物种多样性;而在低海拔山脊上,较低的叶面积指数和平均叶倾角群落林下幼苗层有较高的功能多样性。此结果对科研人员和林业工作者开展野外森林更新情况评估和样方调查将有所帮助。
Forest canopy structure and topography are the most obvious characteristics of forest ecosystems and directly affect forest regeneration,seedling survival,and diversity.To reveal the mechanisms of canopy structure,topography,and spatial variables on understory species diversity and functional diversity,we performed semi-spherical photography and extracted indices of canopy structure in 1.2 hm2 seedling monitoring plot in the 25 hm2 Badagongshan forest plot,then investigated species composition and abundance of seedling communities in each 20 m×20 m quadrat in the seedling monitoring plot.We also sampled leaves of common species close to the reserve and measured leaf functional traits.We applied the spatial simultaneous autoregressive error model(SARs)to test the effects of canopy structure,topography,and spatial factors on seedling species diversity and functional diversity.Results showed that:(1)canopy structure of adult tree communities in the 1.2 hm2 plot was relatively complex and the mean maximum canopy height,mean leaf area index(LAI),mean leaf angle(MLA),and Gndcover were 19.94 m,2.94,30.88°,and 0.87,respectively;(2)Canopy structure and topographical variables explained 32.6%-48.4%and 28.5%-70.2%of variation in the species and functional diversity indices,respectively,but not all topographical variables were entered in the best-fitting model of species diversity indices;(3)Seedling species diversity was higher in habitats with a high altitude and slope and where canopy structure had a lower LAI and MLA,whereas,seedling functional diversity was higher in habitats with a low altitude and slope and where canopy structure had a lower LAI and MLA.These results provide suggestions and guidance for forest regeneration evaluation and vegetation inventory.
作者
徐耀粘
刘检明
万丹
刘梦婷
江明喜
Xu Yao-Zhan;Liu Jian-Ming;Wan Dan;Liu Meng-Ting;Jiang Ming-Xi(Key Laboratory of Aquatic Botany and Watershed Ecology,Wuhan Botanical Garden,Chinese Academy of Sciences, Wuhan 430074, China;Center of Conservation Biology,Core Botanical Gardens,Chinese Academy of Sciences, Wuhan 430074, China;Forestry Prospect & Design Institute of Hubei Province, Wuhan 430079, China;Chongqing Branch Institute,Changjiang River Scientific Research Institute, Chongqing 400026, China;Hubei Academy of Environmental Science, Wuhan 430072, China)
出处
《植物科学学报》
CAS
CSCD
北大核心
2020年第6期733-742,共10页
Plant Science Journal
基金
国家重点研发计划项目(2016YFC0503105)
国家科技基础性工作专项(2015FY1103002-4)
国家自然科学基金(31700356)。
关键词
叶面积指数
叶倾角
功能性状
空间同步自回归模型
八大公山
Leaf area index
Mean leaf angle
Functional traits
Spatial simultaneous autoregressive model
Badagongshan
