The JRC has contributed to the biggest study to date of tundra shrub growth. The international study, published on 6 July in Nature Climate Change, provides strong evidence that dramatic changes in the Arctic are being driven by climate warming and that these significant changes in one of the Earth’s most vulnerable ecosystems are not only a symptom of climate change, but may fuel further warming.
Research into tundra shrubs – which act as a barometer of the Arctic environment – reveals that they grow more when temperatures are warmer. Increased shrub growth, with recent and future climate warming in the Arctic, could cause further warming of tundra ecosystems and for the planet as a whole.
Taller shrubs prevent snow from reflecting heat from the sun back into space, warming the Earth’s surface. They can also influence soil temperatures and thaw permafrost. Increases in shrubs can change the cycling of nutrients and carbon in the soil, affecting soil decomposition and the amount of carbon released to the atmosphere. All these factors can contribute to climate warming both in the Arctic and on a global scale.
Shrub species in wet landscapes at mid-latitudes of the Arctic are the most sensitive to climate warming, the research team says. These areas are vulnerable to change as they store large amounts of carbon in frozen soil, which could be released by warming and permafrost thaw.
The study was carried out by an international team of scientists – including JRC scientist Pieter Beck – at 37 sites in nine countries, and led by the University of Edinburgh. The team studied records of shrub growth spanning 60 years, including analyses of yearly growth rings in the plant stems, to explore links between climate and vegetation change.
The study, published on 6 July in Nature Climate Change, was funded by the International Arctic Science Committee (IASC). The findings will be used to improve climate forecast models of future tundra vegetation change.