Our northern ecosystems are changing and this time sea ice is not the suspect. International scientists headed up by the University of Edinburgh have results from a comprehensive study on vegetation comprising the Arctic tundra. Research was conducted on 37 sites in nine countries, monitoring shrub growth in the Arctic spanning 60 years. Curiously plant growth is not a good thing.
Arctic shrubs, in most cases willows, are growing and moving north at fairly rapid rates. These tundra shrubs act as a barometer of the Arctic and their increased presence is “strong evidence” that climate change is happening. Focus on diminishing sea ice has been the headline for years and this is just auxiliary evidence that global warming is real.
The growth and spreading of these shrubs in itself is not the problem. What occurs and perpetuates increases in temperatures is the way these thicker stands of plant life fuel warming. Taller, thicker growth of shrubs prevents snow from reflecting sun back away from our planet, therefore warming the Earth’s surface. This process leads to soil temperature increase and thawing of permafrost.
Increased shrub stands change nutrient cycling and carbon levels in the soil and thus affect the decomposition rate and then the amount of carbon released into the atmosphere from thawing permafrost. Dr. Isla Myers-Smith was the study co-ordinator for this project and she cautioned on the increased shrub growth; “Arctic shrub growth in the tundra is one of the most significant examples on Earth of the effect that climate change is having on ecosystems.” ( Reported by Press Association July 6, 2015)
The research is documented comprehensively in Nature Climate Change and funded by the International Arctic Science Committee.