[目的]研究林下植物在不同林冠开度梯度下的物种组成和多样性变化,为森林生态系统多样性维持机制提供新的研究案例,并为野生植物的引种应用提供科学依据.[方法]基于广东省银瓶山自然保护区2 hm2固定样地调查数据,将林冠开度(CO)划分为第1梯度(CO＜10％)、第2梯度(10％≤CO≤20％)和第3梯度(20％＜CO＜30％),用多响应置换过程(MRPP)检验林冠开度与林下植物分布的异质性,对林冠开度与个体数、物种数、均匀度、Shannon-Weiner多样性指数、峰度、偏度等指标间进行相关性分析,用指示种分析(Indicator species analysis,ISA)检验林下植物对不同梯度林冠开度的指示作用.[结果]调查区林下植物共有161种,隶属69科,129属;林下植物整体分布均匀.多响应置换过程(MRPP)检验结果表明,不同林冠开度下林下植被的分布和多样性均存在显著差异.相关分析表明,林冠开度与均匀度呈显著正相关(P＜0.05),与偏度和峰度呈显著负相关.指示种分析表明,有多个林下物种对第1梯度(Co＜10％)和第3梯度(20％＜CO＜30％)林冠开度有指示作用.[结论]肖菝葜(Heterosmilax japonica)、三叉苦(Evodia lepta)对第1梯度林冠开度表现极显著的指示作用(P＜0.005),蒲桃(Syzygium jambos)对第3梯度林冠开度起极显著的指示作用(P＜0.01),前者对弱光环境表现较强的适应性,而后者则适应于较强的光照环境.
Composition and diversity of understory plant species in subtropical forests under different canopy openness
[Objective] This study investigated composition and diversity of understory species under different gradients of canopy openness to provide new cases for the research of maintaining species diversity and scientific basis for introduction and utilization of wild plants.[Method] Data collected from 2 hm2 sample plots in Yinpingshan Nature Reserve of Guangdong were analyzed.The canopy openness (CO) is divided into three gradients which are the first gradient (CO＜10％),the second gradient (10％≤CO≤20％),the third gradient(20＜CO＜30％).The heterogeneity will be tested between composition and distribution of understory plant and different canopy openness by Multi-response permutation procedures (MRPP).The correlations between canopy openness and several variables including number of individuals,number of species,evenness,Shannon-Weiner diversity index,skewness and kurtosis were investigated.Indicator species analysis (ISA) was also conducted to test the indication of understory species to different canopy openness classes.[Result] A total of 161 plant species were observed in the understory of studied plots,belonging to 129 genera in 69 families.Species were evenly distributed.Multi-response permutation procedures (MRPP) revealed significant differences in composition and distribution of understory plants under different canopy openness.Canopy openness was significantly and positively correlated with evenness (P＜0.05),while negatively correlated with skewness and kurtosis.ISA showed that a number of understory species had indicating function for low and high canopy openness.[Conclusion] Heterosmilax japonica and Evodia lepta had significant indication effect for low canopy openness (P＜0.005),indicating that they were more adaptive to low light environment,whereas Syzygium jarnbos was more adaptive to high radiation environment with significant indication effect for high canopy openness (P＜0.01).
canopy opennessunderstory plantplant diversitymulti-response permutation procedures (MRPP)indicator species analysis
NETL
NSTL
万方数据
维普
