European Commission, Joint Research Centre, Directorate for Sustainable Resources, Ispra, Italy.
Laboratory of Hydrology and Water Management, Department of Forest and Water Management, Ghent University, B-9000 Ghent, Belgium.
Science. 2017 Jun 16;356(6343):1180-1184. doi: 10.1126/science.aal1727. Epub 2017 May 25.
Changes in vegetation cover associated with the observed greening may affect several biophysical processes, whose net effects on climate are unclear. We analyzed remotely sensed dynamics in leaf area index (LAI) and energy fluxes in order to explore the associated variation in local climate. We show that the increasing trend in LAI contributed to the warming of boreal zones through a reduction of surface albedo and to an evaporation-driven cooling in arid regions. The interplay between LAI and surface biophysics is amplified up to five times under extreme warm-dry and cold-wet years. Altogether, these signals reveal that the recent dynamics in global vegetation have had relevant biophysical impacts on the local climates and should be considered in the design of local mitigation and adaptation plans.
植被覆盖的变化与观测到的变绿有关，这可能会影响几个生物物理过程，其对气候的净影响尚不清楚。我们分析了叶面积指数（LAI）和能量通量的遥感动态，以探索相关的局地气候变化。我们表明，LAI 的增加趋势通过减少地表反照率导致北方地区变暖，并通过蒸发驱动的冷却导致干旱地区降温。在极端暖干和冷湿年份，LAI 和地表生物物理之间的相互作用放大了多达五倍。总的来说，这些信号表明，全球植被的近期动态对当地气候产生了相关的生物物理影响，在制定当地缓解和适应计划时应予以考虑。
