Heavy snowfalls are harmful to the Arctic plants. Precipitation destroy flora indirectly: covered in snow multiply actively pathogenic fungi that cause and die dominant arctic plant communities.
The extent and thickness of the snow cover — one of the main factors, which ensures the stability of the arctic and alpine flora. Snow protects plants from the northern winter cold, keeps the temperature within the optimum and increases the availability of nutrients, thereby contributing to the growth of plants. But due to global warming winters become warmer, and the polar regions increased precipitation — snow.
"In studying the effects of climate change and human impact, the researchers pay particular attention to the amount of precipitation, duration and timing of the winter growing season, — wrote the authors of the new study, which appeared in Nature Climate Change. — However, the snowy Arctic winters may affect not only the availability of nutrients and vegetation. Snowy winter can cause infectious diseases spreading among the plants that affect food chains and cycling eelementov in nature. "
Johan Olofsson (Johan Olofsson) from the University of Umea in Sweden (Umea Universuty) and his colleagues studied the correlation between the thickness of the snow and the development of the plants in the arctic tundra. The scientists used a special snow-boards, through which they simulated the increase in precipitation. For seven years, biologists have observed changes in the community of plants that inhabit the Arctic natural experimental plots.
"First, an increase in snow cover has stimulated plant growth. However, this is not surprising. The snow is really promotes early and active vegetation, — says Robert Baxter (Robert Baxter) from the University of Durham (Durham) in the UK. — But in the sixth year of the experiment of the plant population quickly spread fungus that destroyed the entire community of Arctic flora frost. "
Scientists have determined that the cause of the plague of the Arctic — a fungus Arwidssonia empetri. In the experiment, it is completely destroyed bisexual shrubs crowberry (Empetrum hermaphroditum), one of the dominant species of Arctic plants, which plays an important role in the northern ecosystem.
Biologists believe that this mass mortality of Arctic vegetation could increase the amount of greenhouse gases that are released during the decomposition of dead plants. Moreover, the disappearance of the form will cause a systemic change in the food chain and the carbon cycle.
Fortunately, the killer fungus caused massive sea only in the experiment. But scientists point out that the results can not be considered speculative. "Until now, there are still many gaps in what we can expect from global warming — the authors write a paper published in Nature Climate Change — We believe that the threat may be lurking in the details."
Biologists have warned that because of global warming, polar bears are starving and interbreed with brown. As the results of the new study, the warming can develop and imperceptible at first infectious disease. However, they have an impact on the food chain, ecosystem stability and circulation elements.
"These results will help to better understand and predict the effects of climate change on the Arctic. This is particularly important because the Arctic is different from other geographical areas of vulnerability "- the researchers conclude. Already WWF experts warn that if the scientists say global average temperature rise to 2 degrees, the Arctic, this means 5 degrees, and in some places — up to 10.