植物功能性状能够显示对环境变化的响应，不同的适应对策呈现出不同的功能性状组合。干热河谷地区水分是最主要的限制性环境因子，之前的大部分研究都是集中关注于干热河谷局部地段，对于从垂直海拔上来研究不同植物在环境梯度下的变化的研究较少。干热河谷地区由于梵风效应，水分胁迫沿海拔梯度发生变化，一般表现为随海拔高度升高，气温降低，湿度和降水量增加，而蒸发量减小，辐射增强。以云南元谋干热河谷4个海拔梯度（1491.33、1730.20、1850.00、1925.57 m）中的植物为研究对象，选取叶片干物质含量（LDMC）、叶面积（LA）、比叶面积（SLA）、叶片厚度（LT）和叶密度（LD）5个功能性状，研究它们的相互关系，比较了海拔间的差异。结果表明：1）5个功能性状在不同海拔间均呈现出一定差异，变异系数由高到低为LD>LA>SLA>LT>LDMC（分别是101%、64%、56%、41%和19%）；方差分析结果也表明，5个功能性状在不同海拔之间差异显著（F=56.218，P<0.01；F=7.829，P<0.01；F=11.21，P<0.01；F=7.429，P<0.01；F=19.213，P<0.01），尤其是在最低（1491.33 mm）和最高（1927.57 mm）海拔之间，各性状均具有极显著的差异；2）性状之间存在组合关系， LD与其他性状间相关性最为明显，除LDMC以外，LD与LA、SLA、LT均呈现出极显著负相关关系；LDMC与LA和LT呈极显著负相关；SLA与LA和LT呈正相关，而与LDMC显著负相关；LT与SLA显著正相关，与LA之间相关性不显著；3）在不同的海拔梯度之间，性状组合存在非同步变化现象。研究显示，元谋干热河谷地区，植物对水分环境的海拔梯度变化产生功能性状组合的响应，低海拔和高海拔物种对所处环境的适应策略不同，使得植物在海拔梯度上出现叶片功能性状组合的分化和差异。%The variation of environment is responded by plant functional traits, meanwhile, the different groups of plant functional trait have different ecological strategies of adaption. It is a main factor that is water restriction in dry-hot valleys and the effect of Foehn effect result the variation of water stress had changed along gradients of altitude. A number of researches have focused on local of dry-hot valleys, but the researchs of variation of different species, under the different circumstance, are not well understood in the gradient of elevation. In general, the temperature and evaporation will decrease, moisture, precipitation and solar radiation will increase along increase gradients of altitude. We used five plant functional traits, which is Leaf dry matter content (LDMC), Leaf area (LA), Specific leaf area (SLA), Leaf thickness (LT) and Leaf density (LD), to research the relationship among those traits and compared the variation among four altitudes (1 491.33, 1 730.20, 1 850.00, 1 925.57 m, respectively) in dry-hot valley of Yuan-Mou, Yunnan province. We found that: 1) there was variation that the coefficients from high to low level were LD>LA>SLA>LT>LDMC(101%, 64%, 56%, 41% and 19%, respectively), of five plant functional traits among altitudes. The ANOVA suggest the significant different of plant functional traits among altitudes especially the significant different from highest (1 491.33 mm) and lowest (1 927.57 mm) altitude (F=56.218, P<0.01; F=7.829, P<0.01; F=11.21, P<0.01; F=7.429, P<0.01;F=19.213, P<0.01, respectively);2) there were strong negative correlations between LD and LA, SLA, LT, except LDMC;strong negative correlations between LDMC and LA, LT;positive correlations between SLA and LA, LT, and negative correlated LDMC;positive correlations between LT and SLA, and non-correlated with LA;3) there were allometric scaling among group of functional traits. The results indicate that the response of plant functional traits’ group to change of hydrologic environmental gradients of altitude in dry-hot valley of Yuan-Mou. There are variation and different of group of leaf functional traits for different adaption strategies along altitude gradients.
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