The effect of urbanization on plant phenology depends on regional temperature
The effect of urbanization on plant phenology depends on regional temperature
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DOI：
10.1038/s41559-019-1004-1
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发表时间：
2019-12-01
影响因子：
16.8
通讯作者：
Guralnick, Robert P.
中科院分区：
文献类型：
--
作者：
Li, Daijiang;Stucky, Brian J.;Guralnick, Robert P.
植物和动物的物候变化是为了应对城市化，大多数假设集中在“城市热岛”（UHI）效应的驱动程序。然而，关于物候对城市化的反应的方向和幅度的一般性尚未出现，因为大多数研究都集中在遥感植被物候或在当地规模相对较少的物种。此外，城市化如何与大尺度气候梯度相互作用仍然是一个未知的，但重要的组成部分，气候变化驱动的物候变化。在这里，我们使用了一个数据库，其中包含来自美国和欧洲的超过2200万个原位植物物候学观察结果，以研究不同人口密度（作为城市化指标）和区域温度对广泛植物系统发育谱中开花和落叶日期的联合影响。另外，人口密度的增加和地区温度的升高都促进了植物的开花和落叶。然而，人口密度对植物开花和落叶的影响取决于区域温度：高人口密度在寒冷地区促进植物物候，但这种影响在温暖地区消失甚至逆转。城市热岛效应（通过每日地表温度测量）不能单独解释城市化对植物物候的整体影响，这表明城市化也通过其他机制影响植物物候。较短的植物，大比叶面积和早期开花或叶的日期是最受城市化和温度变化的影响。我们的研究提供了强有力的经验证据表明，城市化对植物物候的影响随区域温度而变化。因此，对物候变化的可靠理解和准确预测必须考虑这种相互作用。
Plant and animal phenology is shifting in response to urbanization, with most hypotheses focusing on the 'urban heat island' (UHI) effect as the driver. However, generalities regarding the direction and magnitude of phenological response to urbanization have not yet emerged because most studies have focused on remote-sensed vegetative phenologies or at local scales with relatively few species. Furthermore, how urbanization interacts with broad-scale climate gradients remains an unknown but important component of anthropogenically driven phenological change. Here, we used a database with >22 million in situ plant phenological observations from the United States and Europe to study the joint influence of varying human population density, which serves as an urbanization measure, and of regional temperature on median flowering and leaf-out dates across a wide plant phylogenetic spectrum. Separately, increasing population density and warmer regional temperature both advanced plant flowering and leaf-out. However, the influence of human population density on plant flowering and leaf-out depends on the regional temperature: high population density advanced plant phenology in cold areas but this effect disappeared or even reversed in warm areas. UHI effects (as measured by daily land surface temperature) alone cannot explain the overall influence of urbanization on plant phenology, suggesting that urbanization also affects plant phenology via other mechanisms. Shorter plants with large specific leaf areas and early flower or leaf-out dates were most affected by urbanization and temperature changes. Our study provides strong empirical evidence that the influence of urbanization on plant phenology varies with regional temperature. Therefore, robust understanding and accurate prediction of phenological changes must take this interaction into account.