不同水盐环境下荒漠植物群落抗逆性化学性状的种间、种内变异

叶片是植物获取资源的重要器官，研究荒漠植物抗逆性化学性状的种间、种内变异对环境变化的响应有助于揭示植物对极端环境的适应机制。以艾比湖自然荒漠植物群落为研究对象，通过野外调查与实验分析，解析不同土壤水盐环境下群落水平抗逆性化学性状（钾K；钙Ca；钠Na；镁Mg）的差异及其种间、种内变异特征，利用冗余分析、相关性分析，明析群落水平性状种间、种内变异与土壤环境因子间关系及其在不同水盐环境间的变化规律。结果表明：（1）高水盐环境下土壤pH及Ca、Na含量均显著高于低水盐环境；低水盐环境下群落水平K、Na、Mg含量显著高于高水盐环境。（2）高水盐环境下群落抗逆性化学性状的种间变异（Ca除外，P<0.05）、种内变异均低于低水盐环境。（3）高水盐环境土壤因子与群落种间、种内变异相关性较高（|r|>0.3），其中与叶片Ca、Na种间变异普遍为负相关，与Na种内变异多为较强的正相关；低水盐环境种间、种内变异与土壤因子相关性总体较低，其中土壤盐分、水分与叶片Mg的种间变异呈负相关，与Na种内变异呈正相关。综上所述，水盐环境对荒漠植物群落水平的抗逆性化学性状有显著影响，各性状的种间、种内变异与土壤因子间关系在高水盐环境中更为密切，本研究为掌握胁迫环境下植物的适应策略提供依据。

Inter- and intraspecific variations of resistant and chemical traits in desert plant community under different soil water and salinity environments

Leaves are sensitive organ for plants responding to the environmental changes. The response of community-level chemical traits to environmental changes and resource competition are driven by inter-and intraspecific variations simultaneously. Therefore, studying the inter-and intraspecific trait variations of desert plant in high and low soil moisture and salinity environments can reveal the shaping effect of soil environmental factors on plants chemical traits. In this study, investigation and sampling were carried out at 32 sampling plots (10 m×10 m), and the clustering method was used to divide these plots into high (11) and low (21) soil moisture and salinity environments. We focused on four key functional traits (potassium K, calcium Ca, sodium Na, magnesium Mg) that belong to leaf chemical trait and measured seven soil factors, including soil water content (SVWC), soil electric conductivity (EC), soil pH, and soil K, Ca, Na, Mg contents, to explore the relationship between trait variations and soil factors. The results indicated that:(1) the soil pH, Ca and Na contents were significantly higher in high soil moisture-salinity environment than those in low soil moisture-salinity environment. The community weighted trait means of foliar K, Na and Mg concentrations in low soil moisture and salinity environment were significantly higher than those in soils with high moisture and salinity content. (2) Based on the results of a sum of squares decomposition method, we observed that the interspecific variations of foliar K, Na and Mg in the high soil moisture and salinity environment were significantly lower than those in the low soil moisture and salinity environment. The intraspecific variations of all traits were higher and the foliar K reached a significant level when facing drought stress. (3) Redundancy analysis (RDA) and correlation analysis results showed that the soil factors were generally negatively correlated with the interspecific variations of Ca and Na (|r|>0.3) in high soil moisture-salinity environment, but were mostly positively correlated with intraspecific variation of Na (|r|>0.3). In environment with drought stress, the correlation between soil factors and inter-and intraspecific variability was relatively low. The soil EC and SVWC were positively correlated with the interspecific variation of foliar Mg and positively correlated with the intraspecific variation of Na when the drought was severe. The results indicated that the same functional traits respond differently to soil factors changes, enabling adaption to specific environment conditions. Overall, these trait-soil relationships at community level will provide mechanistic understanding on the vegetation community assembly in the study area.