Twentieth century redistribution in climatic drivers of global tree growth.

ABSTRACT: 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.

SUBMITTER: Babst F 

PROVIDER: S-EPMC6357745 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature