Long-term research shows patterns of change linked with temperature and soil moisture
By Summit Voice
SUMMIT COUNTY — Swedish scientists from the University of Gothenburg say they’ve linked changes in Arctic vegetation with increasing temperatures. Many Arctic plants are growing taller, the proportion of ground covered with plants has grown, and, above all, there has been an increase in evergreen shrubs.
“We’ve managed to link the vegetation changes observed at the different sites to the degree of local warming, … the vegetation changes in our fixed plots are a result of local warming at numerous sites across the world’s tundra,” said University of Gothenburg. biologist Robert Björk.
Comparisons show that the prevalence of vascular species, such as shrubs and plants, is increasing as temperatures rise. The degree of change depends on climate zone, soil moisture and the presence of permafrost.
The research is part of an international tundra study with data going back 30 years. By analyzing changes in vegetation in 158 plant communities at 46 locations across the Arctic between 1980 and 2010, they have been able to identify a number of general trends.
ITEX was started up in the USA in 1990 when agreement was reached on a joint manual with standardized protocols which have since been used throughout the Arctic.
“The response of different plant groups to rising temperatures often varied with summer ambient temperature, soil moisture content and experimental duration,” said plant ecologist Ulf Molau.
Shrubs are expanding in areas where ambient temperatures were already high, while grasses are expanding in the coldest areas, added Molau, a long-time member of the Intergovernmental Panel on Climate Change.
The results indicate strong regional variation in the response of tundra vegetation to rising temperatures.
“This means that particularly sensitive regions following the combined effects of long-term warming in the Arctic may see much greater changes than we have observed to date,” Ulf Molau says.
The research was published this week in the journals Nature Climate Change and Ecology Letters. The results are timely, as Sweden chairs the Arctic Council for the next few years and is taking the lead on producing the Arctic Resilience Report. The research will also be encompassed in the 2014 IPCC assessment.