延河流域植物叶性状间关系及其在不同植被带的表达

Relationships among leaf traits and their expression in different vegetation zones in Yanhe River basin,Northwest China

以延河流域不同植被带的地带性植物群落为研究对象对群落优势种和主要伴生种的6种叶片性状进行测定分析这些性状及其关系随环境梯度的变化,以了解该区域植物对环境变化的适应策略.结果表明:植物比叶面积(SLA)与叶组织密度(LTD)、叶片单位面积氮和磷含量均呈显著负相关与单位质量叶片磷含量呈显著正相关;各性状间的尺度关系和生存对策在不同植被带不同,典型草原带和森林草原带植物LTD-SLA的尺度依赖关系比森林带植物的强,而森林带植物叶片单位面积N、P含量与SLA、LTD间的尺度关系较草原带更明显,植物对环境的适应策略发生了位移.在干旱贫瘠的草原带和森林草原带植物以防御和抗胁迫策略为主,而在环境条件相对湿润、富养的森林带植物以快速生长和资源优化配置策略为主.

This article selected zonal plant communities as the research objects in different vegetation zones in Yanhe River basin.We measured six leaf traits of the dominant species and main accompanying species in each community,and then analyzed the relationships and their changes along with environmental gradients between these traits in order to understand the plant adaptation strategies to the environment changes.The results showed that the specific leaf area was significantly negatively correlated to leaf tissue density,area-based leaf nitrogen and phosphorus concentrations,and significantly positively correlated to mass-based leaf phosphorus concentration.Both the scaling relationships among these traits and plant life strategies were different among the three vegetation zones,the scaling-dependent relationship between leaf tissue density and specific leaf area was stronger in steppe and forest-steppe zones than in forest zone,but the correlations among area-based leaf nitrogen/phosphorus concentrations and specific leaf area and leaf tissue density were more significant in forest zone than in steppe zone.In the arid grassland and forest-steppe zone,plants give priority to defensive and stress resistance strategies,and in relatively moist nutrient-rich forest zone,plants give priority to fast growth and resource optimization allocation strategies.