Twentieth Century Redistribution in Climatic Drivers of Global Tree Growth

Babst, Flurin ; Bouriaud, Olivier ; Poulter, Benjamin ; Trouet, Valerie ; Girardin, Martin P ; Frank, David C

关键词: CLIMATE CHANGE;    CLIMATOLOGY;    CONSTRAINTS;    EARTH RADIATION BUDGET;    MODELS;    TEMPERATURE GRADIENTS;    TREES (PLANTS);    VARIABILITY;    WATER;   

RP-ID  :  GSFC-E-DAA-TN71499

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Energy and water limitations of tree growth remain insufficiently understood at large spatiotemporal scales, hindering model representation of interannual or longer-term ecosystem processes. By assessing and statistically scaling the climatic drivers from 2710 tree-ring sites, we identified the boreal and temperate land areas where tree growth during 1930–1960 CE responded positively to temperature (20.8 ± 3.7 Mio km2; 25.9 ± 4.6%), precipitation (77.5 ± 3.3 Mio km2; 96.4 ± 4.1%), and other parameters. The spatial manifestation of this climate response is determined by latitudinal and altitudinal temperature gradients, indicating that warming leads to geographic shifts in growth limitations. We observed a significant (P < 0.001) decrease in temperature response at cold-dry sites between 1930–1960 and 1960–1990 CE, and the total temperature-limited area shrunk by −8.7 ± 0.6 Mio km2. Simultaneously, trees became more limited by atmospheric water demand almost worldwide. These changes occurred under mild warming, and we expect that continued climate change will trigger a major redistribution in growth responses to climate.