Abstract：
Forests are continuously altered by disturbances. Yet, knowledge of global pattern of forest disturbance agents, its drivers, and shifts under changing climate remain scarce. Here we present a meta-analysis of current and projected (+2° and + 4 °C) distribution of forest disturbance agents causing immediate tree mortality (i.e., fire, pest outbreak, hydro-geomorphic, and wind) at country, continental, biome, and global scales. The model including combination of climatic (precipitation of driest quarter, actual evapotranspiration, and minimum temperature), geographical (distance to coast and topography complexity), and forest characteristics (tree density) performs better than any other model in explaining the distribution of disturbance agents (R2 = 0.74). We provide global maps (0.5° × 0.5°) of current and potential future distribution of forest disturbance agents. Globally, the most frequent disturbance agent was fire (46.09 %), followed by pest outbreak (23.27 %), hydro-geomorphic disturbances (18.97 %), and wind (11.67 %). Our projections indicate spatially contrasting shifts in disturbance agents, with fire and wind risk increase between ~50°S and ~ 40°N under warming climate. In particular, the substantial increase in fire risk, exceeding 31 % in the most affected areas, is projected over Mediterranean, the western and southeast USA, African, Oceanian, and South American forests. On the other hand, pest outbreak and hydro-geomorphic disturbances are projected to increase in more southern (> ~ 50°S) and northern (> ~ 40°N) latitudes. Our findings are critical for understanding ongoing changes and developing mitigation strategies to maintain the ecological integrity and ecosystem services under shifts in forest disturbances. We suggest that projected shifts in the global distribution of forest disturbance agents needs to be considered to future models of vegetation or carbon sink dynamics under projected climate change.
摘要：
森林不断被干扰改变。然而，了解森林扰动剂的全球格局，它的司机,气候变化下的变化仍然很少。在这里，我们对导致立即树木死亡的森林干扰因子的当前和预计（2°和4°C）分布进行了荟萃分析（即，火,害虫爆发，水文地貌,和风)在国家，大陆,生物群落，和全球规模。该模型包括气候组合(最干旱季度的降水，实际蒸散量，和最低温度)，地理(到海岸的距离和地形复杂性)，和森林特征（树木密度）在解释干扰源的分布方面比任何其他模型都要好（R2=0.74）。我们提供了森林干扰因子当前和潜在未来分布的全球地图（0.5°×0.5°）。全球范围内,最常见的干扰因素是火灾(46.09%)，其次是虫害爆发(23.27%)，水文地貌扰动(18.97%)，和风(11.67%)。我们的预测表明扰动剂的空间对比变化，在气候变暖的情况下，火灾和风的风险在~50°S和~40°N之间增加。特别是,火灾风险的大幅增加，在受影响最严重的地区超过31%，预计在地中海上空，美国西部和东南部，非洲,大洋洲,南美森林另一方面,预计在更多的南部（>〜50°S）和北部（>〜40°N）纬度地区，虫害爆发和水文地貌干扰将增加。我们的发现对于了解正在发生的变化和制定缓解策略以维持森林干扰变化下的生态完整性和生态系统服务至关重要。我们建议，在预计的气候变化下，未来的植被或碳汇动态模型需要考虑森林扰动剂全球分布的预计变化。
