The carbon cycle on Earth depends heavily on terrestrial ecosystems, which annually release 120–130 gigatonnes (Gt) of carbon into the atmosphere. The effect on ecosystem respiration has remained unclear, despite the fact that climate change is causing world temperatures to rise.
Professor Niu Shuli's group at the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences (CAS) has conducted a ground-breaking study that sheds new light on how ecosystems react to global warming by revealing a complex relationship between temperature and ecosystem respiration. The prominent publication Nature Ecology & Evolution has published their findings.
This study is notable for showing that ecosystem respiration does not respond to temperature in a predictable manner. Instead, it displays a non-monotonic behavior, with peak respiration rates at a favorable temperature and a decline as the temperature rises more. Surprisingly, there is a complex relationship between the global annual maximum daily temperature and the ideal temperature for ecosystem respiration.
Understanding the temperature response of ecosystem respiration (ER), a complicated process controlled by numerous variables, can be difficult. Researcher Chen Weinan carefully examined temperature response data from 212 sites worldwide, sourced from the global FLUXNET network, under the supervision of Professor Niu. Their research showed that 183 places across 183 different biomes worldwide have temperature optimum for ER.
Furthermore, across a variety of locales and vegetation types, the research showed a linear association between the temperature maxima of ER and the yearly maximum daily temperature (Tmax), pointing to a type of thermal adaptation.
This revolutionary study provides the first thorough proof of widespread temperature maxima for ecosystem respiration and their global adaptation to Tmax. It shows that, as temperatures continue to rise, respiration rates in terrestrial ecosystems may, shockingly, drop rather than increase, challenging common understanding regarding temperature response patterns for ER.
As the world's temperatures continue to rise, these discoveries are crucial for comprehending the complex interactions between ecosystems and climate change and provide insightful information about the future of the carbon cycle on Earth.