Plant community stability results from shifts in species assemblages following whole community transplants across climates

Climate change will decrease precipitation and increase rainfall variability in Eastern Mediterranean regions, with responses of plant communities largely uncertain. Here, we tested short-term responses of dryland plant communities to contrasting rainfall regimes using reciprocal transplants of soil and seed banks. We exposed three annual plant communities to very different climatic conditions along a steep rainfall gradient. We tested for the role of climate vs. community origin on community response and resistance. In parallel, we asked whether origin-specific climatic adaptations predict compositional shifts across climates. Due to an extreme drought, all plants in the driest climate failed to reach maturity. For the remaining two community origins, the most dry-adapted species in each community increased in dry climate and the wet-adapted species increased in wet climate. Dry community origins showed large compositional shifts while maintaining stable plant density, biomass and spec...

气候变化将导致东地中海区域的降水量减少，同时降雨变异性升高，而该区域植物群落的响应在很大程度上仍未明确。本研究通过土壤与种子库（seed bank）的互易移植实验，探究了旱地植物群落对差异化降雨格局的短期响应。我们将3个一年生植物群落置于沿陡峭降雨梯度分布的迥异气候条件中开展实验，检验了气候条件与群落起源各自对群落响应及抗性的调控作用。同时，本研究还探讨了起源特异性气候适应性能否预测不同气候下的群落组成变化。由于遭遇极端干旱，处于最干燥气候条件下的所有植株均未能成熟。对于剩余的两个群落起源组，各群落中最适应干旱的物种在干旱气候下丰度上升，而适应湿润的物种在湿润气候下丰度提升。干旱起源的群落展现出显著的群落组成偏移，但其植株密度、生物量及spec...保持稳定。