Taller Plant Communities Are More Productive and Sensitive to Climate Warming

Climate warming, a result of increasing greenhouse gas emissions, is causing significant shifts in composition of plant species with different traits worldwide. These changes are especially pronounced in colder or high-altitude regions, where its effects are magnified. Understanding the impact of these warming-induced changes in plant community structure and traits on ecosystems' ability to absorb CO2 from the atmosphere remains a key challenge. This ability, reflected by ecosystem productivity and its temperature sensitivity, plays a vital role in regulating the earth's carbon sequestration and mitigating the effects of greenhouse gas emissions on our climate. 

According to a new study published in Nature Plants, researchers led by Prof. NIU Shuli from the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, delved into the changes brought about by warming in plant community traits and ecosystem carbon sequestration in the Qinghai-Tibetan Plateau (QTP), a region known for its high altitude and cold climate. 

By combining a manipulative warming experiment with a field survey along a 1500 km transect across the QTP, researchers have unveiled a crucial link between climate warming, plant community structure and traits, and ecosystem carbon sequestration. 

They found that as temperatures rise, plant communities in the QTP not only grow taller but also undergo significant changes in composition. What's intriguing is that this increase in plant community height goes beyond mere appearance. It reflects the ecosystem's response to climate warming and plays a vital role in enhancing carbon uptake. Taller plant community signifies higher net ecosystem productivity and its temperature sensitivity under warming, indicating a greater ability to absorb CO2 from the atmosphere. 

“By elucidating the association between warming, plant community traits, and carbon sequestration, this study highlights that the increase in plant height at the community level in the high-altitude biome is crucial to shape ecosystem C budget under climate warming”, said Prof NIU Shuli. “This trait-based association provides new insights into predicting the direction, magnitude, and sensitivity of ecosystem C fluxes in response to climate warming.”

This work was financially supported by the National Natural Science Foundation of China, National Key R & D Program of China, the Second Tibetan Plateau Scientific Expedition and Research (STEP) program, and the China Postdoctoral Science Foundation. 

The field warming experimental plots. (Image by NIU Shuli's team)

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