Thank you for the warming: the most northerly lake comes back to life
Lake Kaffeklubben (detsk. Kaffeklubben Sø, 83 37′) is located on a small (48 ha) of the eponymous island. to the North of Greenland, only 707 km from the pole. This is the most Northern lake on the Earth.
For a long time scientists argued about whether to receive life in such places, the impulse to reproduce as a result of nitrate pollution, or make her stop the impending effects of global warming. It seems that an international group of researchers under the guidance of Bianca Perren of the University of Franche-comté (France) managed to answer this question.
Water near the shore Kaffeklubben. No, not the result of a continuous thawing, and only a puddle formed on the surface of thick ice. Nevertheless, diatoms thrive already, for the first time in 2,400 years. (Photo by Bianca Perren et al.)
Despite the harsh living conditions, once the lake was full Kaffeklubben life in the face of cyanobacteria. The ice over the lake while constant, varying only the thickness. But even under 1-2 m of ice cyanobacteria survive. However, they are most active in summer when the air temperature above the ice reservoir is as high as +1,6 C. But more complex forms of life here. But now, but once…
3 500 years ago, when the lake had just been formed, it occupied several species of diatoms. But, according to studies of lake cores, which the authors said in the journal Geology. about 2 400 years ago, as the local temperature, the population is entirely extinct. Usually, to return, diatoms only several thaws, but the lake is so far North, that up until 1960 — when he returned the first such case I could find. And by 2011 there were already twenty.
Nitrate pollution, even light traces Kaffeklubben, of course, is not found: intensive agriculture up to him somehow not reached. Therefore, a recolonization of the lake occurred solely due to the warming, the researchers highlighted, waiting in the near future, further growth of species diversity of local wildlife.
“The mummy” bolotowsky firs trehmernaya ago well preserved. By the year 2100 in their place can come alive descendants, the researchers believe.(Photo By Alexandre Guertin-Pasquier.)
So, global warming is not the end of the world. As a minimum, because in scale it is much inferior to a number of warming of the last few millions (or even thousands) of years.
Alexander Girtin-The Pasca. paleontologist from the University of Montreal (Canada), presented at the meeting in late September, the Canadian paleontological conference research findings of fossil remains of lush forests that once spread over the island Bylot (Canada). It consisted of pine, willow and spruce. And all anything, Yes only the breadth of the island — 73 13′, and he is a tall (up to 1 951 m). At the latitude of New Land (about halfway between the North and South Islands) the existence of forests before this discovery was considered impossible even at sea level. And Bailote because of the significant temperature elevations are very harsh: the average temperature is -15 C (in Oymyakon), which is more like located North of the Franz Joseph than the same New Earth.
The findings of a canadian only 2.6–3.0 million years, that is, to justify the presence there of the forests of the island drift out over warm can not. But you can explain the warmer climate: the average temperature in these places, according to the scientist, was then equal to 0 C, 15 C above the present. According to Mr. Girtin-the Pasca, if current climate dynamics of the temperature increase to the level trehmernaya ago on the island in the year 2100.
For comparison we will remind that in Russia today the annual average temperature is -2 C; in Murmansk it is 0.6 s, and in Ulan-Ude — -0,1 P. Considering that the latter is surrounded by forests, nature of forest cover of the island Bylot in the period of average zero easy to understand. It remains only to wait for something like that on Wrangel island and the New Earth.