Woody plant encroachment intensifies under climate change across tundra and savanna biomes

作者：Mariana García Criado, Isla H. Myers‐Smith, Anne D. Bjorkman, Caroline E. R. Lehmann, Nicola Stevens · 发表于：Global Ecology and Biogeography · 年份：2020 · DOI：10.1111/geb.13072 · 被引用次数：226 · 研究领域：Climate change and permafrost、Cryospheric studies and observations、Tree-ring climate responses

Abstract Aim Biomes worldwide are shifting with global change. Biomes whose extents are limited by temperature or precipitation, such as the tundra and savanna, may be particularly strongly affected by climate change. While woody plant encroachment is prevalent across both biomes, its relationship to temperature and precipitation change remains unknown. Here, we quantify the degree to which woody encroachment is related to climate change and identify its main associated drivers. Location Tundra and savanna biomes. Time period 1992 ± 20.27–2010 ± 5.62 (mean ± SD ). 1876–2016 (range). Major taxa studied Woody plants (shrubs and trees). Methods We compiled a dataset comprising 1,089 records from 899 sites of woody plant cover over time and attributed drivers of woody cover change across these two biomes. We calculated cover change in each biome and assessed the degree to which cover change corresponds to concurrent temperature and precipitation changes using multiple climate metrics. Finally, we conducted a quantitative literature review of the relative importance of attributed drivers of woody cover change. Results Woody encroachment was widespread geographically and across climate gradients. Rates of woody cover change (positive or negative) were 1.8 times lower in the tundra than in the savanna (1.8 vs. 3.2%), while rates of woody cover increase (i.e., encroachment) were c. 1.7 times lower in the tundra compared with the savanna (3.7 vs. 6.3% per decade). In the tundra, magni...