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对不同林龄刺槐群落叶功能性状差异及其与土壤养分的关系进行研究,分析刺槐对黄土丘陵区土壤环境的适应策略.结果表明:随林龄的增大,刺槐比叶面积、叶面积、叶片含水量、叶全氮含量及叶有机碳含量呈先增大后减小的变化趋势,且在30年林龄时达到最大值,分别为279.18 cm~2·g~(-1)、33 cm~2、0.09%、33.01g·kg~(-1)1、523.08g·kg~(-1).随林龄的增大,叶组织密度、叶全磷含量、叶厚度及气孔密度呈增大趋势,气孔长度及气孔宽度呈减小趋势.主成分分析表明,叶面积、比叶面积、叶全磷含量、叶片含水量、叶厚度及气孔密度均为刺槐叶功能性状随林龄变化的主要指标.各指标间呈一定的相关性,这表明刺槐能改变自身的形态结构,形成最佳功能组合以适应环境的变化.影响叶面积、叶片含水量、比叶面积及气孔长度的主要土壤因子是土壤全氮含量,影响气孔宽度、叶组织密度、叶厚度、叶全磷含量、叶全氮含量及气孔密度的主要土壤因子是土壤有机碳含量,这表明土壤全氮含量和有机碳含量是影响不同林龄刺槐叶功能性状的主要土壤因子.随林龄的增大,刺槐群落土壤养分得到改善,进而影响刺槐叶功能性状.不同林龄刺槐叶功能性状的差异反映出刺槐具有较强的叶片形态可塑性,有利于其适应黄土丘陵区的土壤环境.
The leaf functional traits of Robinia pseudoacacia communities at different ages and its relationship with soil nutrients were studied to analyze the adaptation strategies of Robinia pseudoacacia to the soil environment in the loess hilly region.The results showed that the specific area of Robinia pseudoacacia increased with leaf area, leaf area, Leaf water content, leaf total nitrogen content and leaf organic carbon content firstly increased and then decreased, and reached their maximum at 30 years of age, which were 279.18 cm 2 · g -1, 33 cm ~ 2,0.09%, 33.01g · kg -1 and 1,523.08g · kg -1, respectively.With increasing age, leaf tissue density, leaf total phosphorus content, leaf thickness and stoma density increased Trend, stomatal length and stoma width decreased.The principal component analysis showed that the leaf area, specific leaf area, total phosphorus content, leaf water content, leaf thickness and stoma density were the main indexes of Robinia pseudoacacia leaf functional traits with age. The results showed that Robinia pseudoacacia could change its morphological structure and form the best combination of functions to adapt to the changes of environment.The main soil factors affecting leaf area, leaf water content, specific leaf area and stoma length were soil Total nitrogen content, affecting stomatal width, leaf tissue density , Leaf thickness, leaf total phosphorus content, leaf total nitrogen content and stoma density were the main soil factors that affected the functional traits of Robinia pseudoacacia at different ages, which indicated that soil total nitrogen content and organic carbon content were the main soil factors The soil nutrient of Robinia pseudoacacia community improved and the functional traits of R. pseudoacacia were affected by the increase of age.The differences of functional traits of Robinia pseudoacacia from different ages showed that Robinia pseudoacacia had stronger morphological plasticity of leaves and was favorable to adapt to the soil environment in the loess hilly region.