Tree species diversity protects forests from climate extremes

A study published in Nature Communications, involving researchers from Peking University and Anglia Ruskin University, indicates that tree species diversity plays a critical role in protecting forests against combined climate extremes. Analyzing forest plots in the United States between 2001 and 2020, the research highlights that simultaneous events, such as intense heat and drought, cause damage far exceeding the impact of individual events.

When thermal and hydric stresses occur together, they increase evapotranspiration and exacerbate water stress. Conversely, excessive moisture combined with heat can lead to soil saturation, causing root asphyxiation. These compound extremes reduce forest resistance and compromise recovery capacities.

Additionally, the effectiveness of forests in mitigating climate change is subject to limitations regarding carbon cycles. While plants fix carbon through photosynthesis, this process is intermittent and can cease during droughts, extreme temperatures, or seasonal changes. There is a distinction between carbon fixation and long-term sequestration, which is necessary for forests to serve as reliable climate auxiliaries.