黔中木本植物叶功能性状对退化喀斯特土壤特性的响应

Response of Leaf Functional Traits of Woody Plants to Degraded Karst Soil in Central Guizhou

研究不同退化背景下优势木本植物功能性状的适应机制,有助于从功能生态学的角度来解释喀斯特山区的群落演替过程。本研究以贵州普定不同退化背景样地优势木本为研究对象,测定LT、LA、SLA、LDMC、LTD、Chlc 6个叶片功能性状指标,分析土壤特性对区域内植被叶片功能性状的作用及影响,揭示喀斯特山区植物对不同环境的适应策略及其演替过程。结果表明:①喀斯特区退化环境下植被叶片向增大化趋势发展,以退耕地经济林最显著;火烧、火烧砍伐、退耕下植被性状差异显著,以LA、LTD、SLA变化范围最大,在相应样地可分别高达121.9%、118.08%、86.00%。②退化样地内叶片性状在乔木、灌木和藤本物种间差异显著,总体上灌木与藤本物种种间变异高于乔木物种,群落处于演替前中期阶段。③不同退化背景下土壤特性差异较大,与植被叶功能性状间具有显著相关性,其中土层深度、土壤养分与土壤含水率是植被叶功能性状的关键土壤特性因子。④退化区域植被叶性状表现出LA大、LT较小、SLA和LTD低、LDMC高、Chlc较低,趋向于发展贫瘠干旱性状组合。揭示了黔中退化喀斯特次生林内在差异性的演替规律,为喀斯特次生林的管理和生物多样性保护提供科学依据。

Studying the adaptive mechanism of functional characters of dominant woody plants under different degradation environment is helpful to explain the succession process of karst mountain community from the perspective of functional ecology.In this study,the dominant woody plants in different degraded background plots in Puding,Guizhou Province were selected as the research objects.Six leaf functional traits(LT,LA,SLA,LDMC,LTD,Chlc)were measured to analyze the effects of soil characteristics on the leaf functional traits of vegetation in the region,and to reveal the adaptation strategies and succession process of plants in karst mountainous areas under different environments.Results indicated that:(1)under the degraded environment of karst area,the vegetation leaves tended to increase,with the most significant change in the economic forest returned from the farmland;There were significant differences in vegetation characteristics under burning,burning felling and returning farmland,with the largest change range of LA,LTD and SLA,which could reach 121.9%,118.08%and 86.00%,respectively in the corresponding sample plots.(2)In the degraded plots,the leaf traits were significantly different among tree,shrub and vine species.In general,the interspecific variation of shrub and vine species was higher than that of tree species,indicating the community was in the early and middle stage of succession.(3)Soil properties under different degradation background are quite different,and there is a significant correlation between soil properties and vegetation leaf functional properties.Soil depth,soil nutrients and soil humidity are the key soil characteristic factors of vegetation leaf functional properties.(4)The results showed that the leaf traits of vegetation in degraded area showed large LA,small LT,low SLA and LTD,high LDMC and low Chlc,which tended to develop drought character combination.Revealing the internal differentiation succession law of degraded karst secondary forest in central Guizhou will provide scientific basis for the management and biodiversity protection of karst secondary forest.