Pellegrini Adam F A, Anderegg William R L, Paine C E Timothy, Hoffmann William A, Kartzinel Tyler, Rabin Sam S, Sheil Douglas, Franco Augusto C, Pacala Stephen W
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
Department of Biology, University of Utah, Salt Lake City, UT, USA.
Ecol Lett. 2017 Mar;20(3):307-316. doi: 10.1111/ele.12725. Epub 2017 Jan 11.
Fire regimes in savannas and forests are changing over much of the world. Anticipating the impact of these changes requires understanding how plants are adapted to fire. In this study, we test whether fire imposes a broad selective force on a key fire-tolerance trait, bark thickness, across 572 tree species distributed worldwide. We show that investment in thick bark is a pervasive adaptation in frequently burned areas across savannas and forests in both temperate and tropical regions where surface fires occur. Geographic variability in bark thickness is largely explained by annual burned area and precipitation seasonality. Combining environmental and species distribution data allowed us to assess vulnerability to future climate and fire conditions: tropical rainforests are especially vulnerable, whereas seasonal forests and savannas are more robust. The strong link between fire and bark thickness provides an avenue for assessing the vulnerability of tree communities to fire and demands inclusion in global models.
世界上大部分地区的稀树草原和森林的火灾状况正在发生变化。要预测这些变化的影响，就需要了解植物是如何适应火灾的。在这项研究中，我们测试了火灾是否对全球分布的572种树木的关键耐火性特征——树皮厚度施加了广泛的选择压力。我们发现，在温带和热带地区发生地表火灾的稀树草原和森林中，频繁燃烧的地区普遍存在对厚树皮的适应性投资。树皮厚度的地理变异性在很大程度上由年燃烧面积和降水季节性来解释。结合环境和物种分布数据使我们能够评估树木群落对未来气候和火灾条件的脆弱性：热带雨林尤其脆弱，而季节性森林和稀树草原则更具韧性。火灾与树皮厚度之间的紧密联系为评估树木群落对火灾的脆弱性提供了一条途径，并且需要将其纳入全球模型中。
