Rapid warming has so affected northern ecosystems that scientists are increasingly concerned about the region’s ability to recover from climate shocks, according to a new study on Arctic plant resilience. Researchers found that frequent natural disasters such as wildfires, drought and deforestation reduce the resilience of many plant communities in the southern boreal forests.

Plant resilience and carbon storage

This reduction in resilience, the ability of plants to recover from environmental stressors, could have significant impacts on the Arctic’s role in carbon sequestration, potentially transforming the region from a carbon sink to a carbon source in the near future.

This change is particularly concerning because the polar and northern regions have warmed several times faster than other parts of the world, and warming is expected to continue.

Yue Zhang is the study’s lead author and a graduate student in earth sciences at The Ohio State University.

“When we talk about forests’ response to climate change, we often think of tropical forests,” Zhang explained. “But remote boreal forests are really important for their vast areas, large stores of carbon, and potential for mitigating climate change.”

Different levels of plant resistance

Based on historical data from NASA’s Arctic Vulnerability Experiment (ABoVE), researchers used remote sensing technology to monitor subtle changes in green vegetation in Alaska and Western Canada between 2000 and 2019.

The goal was to evaluate how quickly vegetation recovered from both minor fluctuations and major losses, even in areas where no significant damage had yet occurred.

The results showed that plant persistence in the southern boreal forest decreased over time, while persistence increased in most of the arctic tundra despite greening. Fires, drought, and heat likely contributed to reduced resilience in southern regions, while changes in nutrient availability may have contributed to the development of vegetation elsewhere in the Arctic.

Uncertainty of carbon storage by plants

However, although the release of nutrients supports plant growth, rising temperatures threaten to accelerate the melting of permafrost. Permafrost stores enormous amounts of carbon, and its thawing could release carbon emissions equivalent to those of 35 million cars per year, accelerating climate tipping points.

Zhang highlighted uncertainty about how much of this carbon will be absorbed by plants and how much will contribute to further warming.

“This is concerning because although greening indicates that productivity and carbon sequestration in these regions are currently increasing, the decline in resilience suggests this may be unsustainable in the long term.”

The entire ecosystem is under threat

The results of the research show that the entire ecosystem is under threat due to the destabilization of a large part of the southern polar forests. This could lead to massive forest loss and biome change in the future. Greening of areas experiencing concurrent declines in resilience may indicate signs of distress, indicating that an ecosystem is struggling to survive before experiencing significant forest loss.

“This is a hotspot of vegetation change, and this study can tell us about the stability of the ecosystem and what it can tolerate before shifting to an alternative state due to widespread forest loss,” warns Professor Yanglan Liu, senior author of the study.

Estimation of plant resistance

Experts also found that high-altitude regions with hot, dry conditions and dense vegetation are among the most vulnerable to reduced resilience.

However, there is still no consensus on how vegetation changes and carbon dynamics interact in current climate models. The team’s work will help improve these models by providing information about where vegetation changes are most likely.

Ultimately, Zhang said, the study found more subtle changes in the state of the region’s vegetation than previously reported greening and darkening trends. Their methodology also provides a new tool for determining potential vegetation loss in other regions in the coming decades.

Future research directions

The team plans to continue improving their predictions of ecosystem change and advocate for more field studies to validate remote sensing data.

“Scientists need to learn how to measure climate-related risks through different lenses,” Liu said. he said. “In addition to satellite remote sensing, we need more ground-based observations to help us identify ways to use these findings to inform future resource and risk management strategies.”

As the Arctic and northern regions warm at an alarming rate, this research highlights the fragility of these ecosystems and the urgent need for strategies to maintain their resilience in the face of rapid climate change. The study was published in the journal Nature Ecology and Evolution.