Five-year field experiment in boreal forests of Minnesota has identified the sensitivity of the dominant tree species to the high temperature environment, they all responded to warming in the early start of the growing season. If that will happen in natural conditions over large areas, the relationship between species in taiga ecosystems are rebuilt, and even rupture, and the risk of seizure of the trees and invasive insects will grow, according to a paper published in the Proceedings of the National Academy of Sciences.
Taiga is the largest land biome on the planet, its boreal forests comprise almost a third of all forests in the world. It is believed that taiga tree species (especially conifers) is extremely vulnerable to climate change. At the same time, they play a leading role in global climate stabilization, as bind large amounts of carbon from the atmosphere and permanently fix it in trudnoreshaemyh forest litter.
The impact of climate change on coniferous and mixed forest to study is not easy: as a rule, all of the warming in the environment are local in nature and manifest themselves in extreme ways over short time intervals and for the correct conclusions it is necessary to observe a stable warming and to compare affected to unaffected plants.
Scientists led by Rebecca Montgomery (Rebecca A. Montgomery) at the University of Minnesota conducted a multiyear field experiment to monitor the response of boreal tree species to increase the ambient temperature. They chose 10 types of trees — deciduous or six (two oak, two maple, poplar and birch) and four conifers (two species of pine, spruce and fir) that grow at the three sites. The first of them (control) temperature corresponded to the ambient temperature, the second support at a level above 1.7 degrees Celsius, and the third is higher by 3.4 degree Celsius, and warmed up in the two test areas is not only the air but also the soil. Phenological parameters (date and number of Bud break, leaf emergence) were recorded twice per week during the growing seasons from 2009 to 2013.