Evolutionary relationships can be more important than abiotic conditions in predicting the outcome of plant-plant interactions

Positive and negative plant–plant interactions are major processes shaping plant communities. They are affected by environmental conditions and evolutionary relationships among the interacting plants. However, the generality of these factors as drivers of pairwise plant interactions and their combined effects remain virtually unknown. We conducted an observational study to assess how environmental conditions (altitude, temperature, irradiance and rainfall), the dispersal mechanism of beneficiary species and evolutionary relationships affected the co-occurrence of pairwise interactions in 11 Stipa tenacissima steppes located along an environmental gradient in Spain. We studied 197 pairwise plant–plant interactions involving the two major nurse plants (the resprouting shrub Quercus coccifera and the tussock grass S. tenacissima) found in these communities. The relative importance of the studied factors varied with the nurse species considered. None of the factors studied were good predict...正负植物间相互作用是塑造植物群落的核心生态过程。这类相互作用会受到环境条件以及互作植物间演化关系的调控。然而，这些因子作为植物两两互作驱动因子的普适性，及其联合效应，目前仍几乎未被探明。本研究开展了一项野外观测研究，旨在评估环境条件（海拔、气温、辐照度与降雨量）、受益物种的扩散机制以及演化关系，如何影响西班牙境内沿环境梯度分布的11处细叶针茅（Stipa tenacissima）草原群落中植物两两互作的共存模式。本研究共分析了197组植物两两互作样本，涵盖该群落中两种主要护聚植物（nurse plant）：萌蘖型灌丛刺叶栎（Quercus coccifera）与丛生禾草细叶针茅（S. tenacissima）。所研究因子的相对重要性因所关注的护聚植物物种而异，目前尚无任何一项被研究的因子可有效预测……