State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China.
Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark.
Nat Plants. 2024 Oct;10(10):1473-1483. doi: 10.1038/s41477-024-01794-w. Epub 2024 Sep 11.
Tree species diversity is essential to sustaining stable forest ecosystem functioning. However, it remains unclear how boreal tree species diversity has changed in response to climate change and how it is associated with productivity and the temporal stability of boreal forest ecosystems. By combining 5,312 field observations and 55,560 Landsat images, here we develop a framework to estimate boreal tree species diversity (represented by the Shannon diversity index, H') for the years 2000, 2010 and 2020. We document an average increase in H' by 12% from 2000 to 2020 across the boreal forests. This increase accounts for 53% of all boreal forest areas and mainly occurs in the eastern forest-boreal transition region, the Okhotsk-Manchurian taiga and the Scandinavian-Russian taiga. Tree species diversity responds positively to increasing temperatures, but the relationship is weakened for higher temperature changes, and in areas of extreme warming (>0.065 °C yr), a negative impact on tree species diversity is found. We further show that the observed spatiotemporal increase in diversity is significantly associated with increased productivity and temporal stability of boreal forest biomass. Our results highlight climate-warming-driven increases in boreal tree species diversity that positively affect boreal ecosystem functioning but are countered in areas of extreme warming.
树种多样性对于维持稳定的森林生态系统功能至关重要。然而，目前尚不清楚北方树种多样性如何响应气候变化，以及它与生产力和北方森林生态系统的时间稳定性有何关联。通过结合 5312 个实地观测数据和 55560 个 Landsat 图像，我们开发了一个框架，用于估计 2000 年、2010 年和 2020 年北方树种多样性（以香农多样性指数 H'表示）。我们记录到，在北方森林中，H'平均每年增加 12%，从 2000 年到 2020 年。这一增长占所有北方森林面积的 53%，主要发生在东部森林-北方过渡带、鄂霍次克-满洲里泰加林和斯堪的纳维亚-俄罗斯泰加林。树种多样性与温度升高呈正相关，但对于更高的温度变化，这种关系减弱，在极端变暖（>0.065°C yr）地区，发现对树种多样性有负面影响。我们进一步表明，观察到的多样性的时空增加与北方森林生物量生产力和时间稳定性的增加显著相关。我们的研究结果强调了气候变暖驱动的北方树种多样性增加，这对北方生态系统功能有积极影响，但在极端变暖地区则会产生相反的影响。
