Environment: Forest resilience trends linked to climate change

Some forests are experiencing substantial declines in resilience in response to climate change, suggests a study published online in Nature this week. Understanding the factors that affect forest resilience might aid the development of conservation and management plans.

Forests cover nearly a third of the Earth’s land surface. They have an important role in the global carbon cycle and potential mitigation of future climate change, as well as in protecting soil from erosion and supporting biodiversity. Maintaining these functions requires a level of resilience — an ability to withstand and recover from environmental disturbances. How forest resilience has evolved in response to climate change has been poorly understood.

Changes in forest resilience between 2000 and 2020 are assessed by Giovanni Forzieri and colleagues, using a combination of satellite-based imaging and machine learning. They show that the resilience of tropical, arid and temperate forests has declined over this period; these changes are associated with reduced water availability and increasing climate variability. Boreal forests, which are typically found in cooler regions of the northern hemisphere, buck this trend, displaying an increase in resilience. The authors suggest that the warming and increased CO2 availability to these forests might outweigh negative impacts of climate change in these regions.

Overall, around 23% of intact undisturbed forests may have already reached a critical threshold, with resilience continuing to decline, the authors estimate. Declines in forest resilience could have critical consequences for the key ecosystem services that they offer, such as carbon storage. The authors conclude that observed trends in forest resilience should be accounted for in strategies to protect forests.