A global test for phylogenetic signal in shifts in flowering time under climate change

1.Shifts in the timing of flowering are a conspicuous biological signal of climate change. These shifts have been documented across the globe for diverse communities. Although many species are flowering earlier, others have exhibited no shifts or delays in flowering. 2.How species respond phenologically will shape interactions both with other community members and with the abiotic environment, altering fitness, abundance, and ultimately persistence. 3.To understand if variability in phenological response is influenced by evolutionary history, we tested for phylogenetic signal in shifts in flowering onset for thirteen communities representing 116 families across the Northern Hemisphere. We compared the fit of models of neutral evolution (Brownian Motion) with models that incorporate selection (Ornstein-Uhlenbeck). 4.We found significant signal in whether species had shifted and the magnitude of response, with both traits conforming to an Ornstein-Uhlenbeck model of trait evolution. 5.Syn...1. 开花物候的时间偏移是气候变化的显著生物学信号。此类偏移已在全球范围内的多样群落中被观测记录。尽管多数物种的开花时间提前，但另有部分物种的开花物候未发生变化，甚至出现延迟。 2. 物种的物候响应方式，将塑造其与群落内其他物种以及非生物环境的相互作用，进而影响适合度、种群丰度，最终改变物种的存续能力。 3. 为探究物候响应的差异是否受进化历史影响，我们针对覆盖北半球116个科的13个群落，开展了开花始期偏移的系统发育信号（phylogenetic signal）检测。我们对比了中性进化模型（布朗运动，Brownian Motion）与纳入选择作用的奥恩斯坦-乌伦贝克模型（Ornstein-Uhlenbeck）的拟合效果。 4. 研究发现，物种是否发生开花物候偏移以及响应幅度均存在显著的系统发育信号，且这两类性状均符合奥恩斯坦-乌伦贝克的性状进化模型。 5. Syn...