Functional correlations between specific leaf area and specific root length along a regional environmental gradient in Inner Mongolia grasslands

Among above- and belowground traits, specific leaf area (SLA, cm2 g−1) and specific root length (SRL, m g−1) are the two key traits reflecting species resource acquisition strategies. However, patterns of variation in SLA and SRL have rarely been examined simultaneously across evolutionary history and environmental gradients, and the SLA-SRL relationship is still controversial on several grounds. We examined the inter- and intraspecific variations in SLA and SRL of different root branching orders and the SLA-SRL relationship across 55 species and 21 plant communities of four vegetation types along a 2,000-km transect in the Inner Mongolia grassland. With increasing root branching order, the interspecific variation in SRL increased but the intraspecific variation in SRL decreased considerably, and the form of SLA-SRL relationship shifted from positive to negative. This indicates that acquisition of soil resources (e.g. water and nutrients) is a fundamental strategy for plant investment t...

在地上与地下性状中，比叶面积（specific leaf area, SLA, cm² g⁻¹）与比根长（specific root length, SRL, m g⁻¹）是反映物种资源获取策略的两类关键性状。然而，学界极少同时从进化历史与环境梯度两个维度探究SLA与SRL的变异格局，且SLA与SRL之间的关联在多个层面仍存在争议。本研究针对内蒙古草原沿2000公里样带分布的4种植被类型、21个植物群落中的55个物种，测定了不同根分枝等级下SLA与SRL的种间及种内变异，并分析了二者的关联。结果显示：随着根分枝等级提升，SRL的种间变异逐渐增大，但种内变异显著降低；同时SLA与SRL的关联形式由正相关转为负相关。这表明获取土壤资源（例如水分与养分）是植物投资的核心策略之一...