生態学：温暖化する北極圏における植物構成の変化

Key drivers behind vascular plant composition changes in a warming Arctic are identified in an analysis of over 40 years of survey data, reported this week in Nature. The study finds overall species loss or gain did not occur, but turnover was widespread, which is likely to affect ecosystem function and all life in the Arctic.

Around the world, global warming is changing how plant species grow, which species are present and where they are found. Currently, the Arctic is experiencing warming four times faster than the global average. Despite existing experimental observations and modelling studies, exactly how this affects plant populations remains unclear.

To identify changes in plant composition and richness, Mariana García Criado and colleagues examined 42,234 records of 490 vascular plant species from 2,174 plots across the Arctic between 1981 and 2022. Contrary to existing hypotheses, the authors found that, on average, plant richness did not change. In accordance with current literature, species richness was found to be in higher proportions in areas with lower latitudes and at higher temperatures. Where changes were observed, species turnover was widespread, occurring in 59% of the surveyed plots. Repeat surveys between 1981 and 2022 helped to identify the key drivers behind changes in species richness and composition; for example, the expansion of shrubs was associated with reduced biodiversity and warming temperatures were associated with greater proportions of species gains and losses.

Although overall richness loss was not observed, Artic plant composition is changing in a warming climate. The authors state the importance of further studies on the impact of plant dynamic shifts on ecosystem function, animal habitats and livelihoods for Arctic people.