胡杨叶功能性状差异及其与树形因子的关系

Differences in leaf functional traits of Populus euphratica at different growth stages and its relationship with tree shape factors

叶片是植物光合作用的主要场所,其生理变化可反映不同生境下植物适生策略。探究塔里木河下游不同生长阶段的胡杨叶功能性状差异及其与树形因子的关系,以期为荒漠河岸林资源保护提供理论依据。结果表明:筛选的10个叶功能性状指标存在不同程度变异,变异系数介于10.7%~39.6%之间;其中叶干重变异系数最大,叶片厚度变异系数最小。幼树、中树、成树和老树叶功能性状间均存在相关性,即比叶面积与叶干物质含量、叶组织密度、叶面积、叶鲜重、比叶重呈极显著负相关(P<0.01),与叶片厚度呈极显著正相关(P<0.01)。树形因子对叶功能性状变异的共同解释量为79.33%,其中,枝下高、树高和冠幅是叶功能性状变异的主要影响因素,而枝下高对叶功能性状的正效应最为明显。总之,树形因子对胡杨叶功能性状的影响显著,不同生长阶段的胡杨通过叶片多个功能性状的协调和权衡分配来适应荒漠恶劣的生态环境。

Leaves are the main site of plant photosynthesis, and they can respond to plant adaption strategies in different habitats through physiological changes. This study predominantly investigated the differences in leaf functional traits of Populus euphratica at different growth stages in the lower reaches of the Tarim River and analyzed the relationship between tree shape factors and leaf functional traits. The aim of this study was to provide a theoretical basis for desert riparian forest conservation and management. Results showed that: there have been different degrees of variation within the 10 leaf trait parameters, with coefficients of variation ranging from 10.7% to 39.6%. Among them, the degree of variation of leaf dry weight was the largest and the degree of variation of leaf thickness(LT) was the smallest. Correlations were found among functional leaf traits in young, adult, mature, and old trees. The specific leaf area was highly significantly negatively correlated(P<0.01) with leaf dry matter content, leaf tissue density, leaf area, leaf fresh weight, specific leaf weight, and was highly significantly positively correlated(P<0.01) with LT. Tree shape factors jointly explained 79.33% of the variation in leaf functional traits, where tree height, crown diameter, and height to crown base were the main influencing factors for variation in leaf functional traits. Meanwhile, crown diameter had the most significant positive correlation between leaf functional traits. The effect of tree shape factors on functional traits of Populus euphratica leaves is significant. Populus euphratica has adapted to the desert environments through the coordination and trade-off distribution of multiple functional traits.