Hantson Stijn, Scheffer Marten, Pueyo Salvador, Xu Chi, Lasslop Gitta, van Nes Egbert H, Holmgren Milena, Mendelsohn John
Karlsruhe Institute of Technology, Institute of Meteorology and Climate research, Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany.
Environmental Sciences Department, Wageningen University, Wageningen, The Netherlands.
Sci Rep. 2017 Oct 30;7(1):14374. doi: 10.1038/s41598-017-14654-9.
Wildfires burn large parts of the tropics every year, shaping ecosystem structure and functioning. Yet the complex interplay between climate, vegetation and human factors that drives fire dynamics is still poorly understood. Here we show that on all continents, except Australia, tropical fire regimes change drastically as mean annual precipitation falls below 550 mm. While the frequency of fires decreases below this threshold, the size and intensity of wildfires rise sharply. This transition to a regime of Rare-Intense-Big fires (RIB-fires) corresponds to the relative disappearance of trees from the landscape. Most dry regions on the globe are projected to become substantially drier under global warming. Our findings suggest a global zone where this drying may have important implications for fire risks to society and ecosystem functioning.
每年，野火都会烧毁大片热带地区，塑造着生态系统的结构和功能。然而，驱动火灾动态变化的气候、植被和人为因素之间复杂的相互作用仍未得到充分理解。在此我们表明，在除澳大利亚之外的所有大陆上，当年平均降水量低于550毫米时，热带火灾模式会发生急剧变化。虽然低于这个阈值时火灾发生频率会降低，但野火的规模和强度会急剧上升。这种向罕见-强烈-大型火灾（RIB火灾）模式的转变对应着树木在景观中的相对消失。预计全球大多数干旱地区在全球变暖的情况下会变得更加干旱。我们的研究结果表明，这样一个干旱化的全球区域可能会对社会面临的火灾风险和生态系统功能产生重要影响。
