Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA.
School of Biological Sciences, The University of Utah, Salt Lake City, Utah, USA.
Ecol Lett. 2022 Dec;25(12):2637-2650. doi: 10.1111/ele.14128. Epub 2022 Oct 18.
Considering the global intensification of aridity in tropical biomes due to climate change, we need to understand what shapes the distribution of drought sensitivity in tropical plants. We conducted a pantropical data synthesis representing 1117 species to test whether xylem-specific hydraulic conductivity (K ), water potential at leaf turgor loss (Ψ ) and water potential at 50% loss of K (Ψ ) varied along climate gradients. The Ψ and Ψ increased with climatic moisture only for evergreen species, but K did not. Species with high Ψ and Ψ values were associated with both dry and wet environments. However, drought-deciduous species showed high Ψ and Ψ values regardless of water availability, whereas evergreen species only in wet environments. All three traits showed a weak phylogenetic signal and a short half-life. These results suggest strong environmental controls on trait variance, which in turn is modulated by leaf habit along climatic moisture gradients in the tropics.
考虑到气候变化导致热带生物群落干旱程度在全球范围内加剧，我们需要了解是什么塑造了热带植物对干旱的敏感性分布。我们进行了一项泛热带数据综合分析，代表了 1117 个物种，以测试木质部特定水力传导率（K ）、叶片膨压丧失时的水势（Ψ ）和 K 损失 50%时的水势（Ψ ）是否沿气候梯度变化。只有常绿物种的 Ψ 和 Ψ 随着气候湿度的增加而增加，而 K 则没有。具有高 Ψ 和 Ψ 值的物种与干燥和湿润环境都有关联。然而，无论水分供应如何，干旱落叶物种都表现出高 Ψ 和 Ψ 值，而常绿物种仅在湿润环境中。所有这三个特征都表现出微弱的系统发育信号和短半衰期。这些结果表明，性状方差受到强烈的环境控制，而这种控制又受到热带气候湿度梯度下叶片习性的调节。
