Washington. U.S. government research institutions to collaborate with scientists around the world in an effort to better understand how climate change will affect forests, and to develop countermeasures to promote adaptation to climate change.
Scientists from the U.S. Forest Service (USFS) and the U.S. Geological Survey (USGS) indicate lack of scientific understanding of forest responses to current climate change, both regionally and on a global scale. For example, what the climate can sustain the load tree before it starts to die? What fever trees can tolerate before they die? What degree of drought they are able to survive? How the tree should weaken before it destroy harmful insects?
"We know that these physiological loading thresholds exist, but we do not know their options — explains USGS research ecologist Craig Allen. — We see a lot of trees dying in the forests of all types around the world, but for lack of a global system forest monitoring, we do not really know whether the enhanced extinction of forests in general as a result of climate change. "
Biologists U.S. Forest Service in California conducted a study of how trees can spread the disease at two different projections of climate change. "Depending on whether the climate is getting hotter and drier and warmer and more humid, the effects of the forest will be completely different," — says biologist Susan Frankel, which specializes in research on sudden oak death — a disease that kills the trees in the United States and? Britain.
Scientists are working to better understand the biological processes for certain types of trees and forests of various types, but all over the world, forests cover one third of the land. "It's very difficult — to understand" the general reaction of forests as a factor of change in the global atmosphere and climate, says Constance Millar — Frankel colleague working at the Research Station Pacific Southwest Forest Service, U.S. Department of Agriculture in California.
Scientists seeking to understand climate change at the global level, "not in a position to explain the relationship between local scales — in which we specialize with Susan — and what is happening on a global scale — Millar said in a joint interview with Frankel. — Science little aware of how these forests interact globally with the water cycle, with the formation of clouds and the impact of greenhouse gases on temperature. "
Scientists are working to overcome the uncertainty and to collect more extensive data on forests and in forests and their role in climate change. Allen is known in the international scientific community for his work in the areas of change in forests and tree mortality due to climate change. He was the lead author of a paper published in 2010 in the journal Forest Ecology and Management, which was presented to a global review of risks to forests in relation to climate change.
Allen analyzed the scientific literature, has collaborated with scientists from 12 other countries, all of whom watched the extinction of forests, for example documented 88 mass tree mortality caused by climate change, including drought and heat stress.
"Examples range from the modest but noticeable increase background levels of tree mortality and to climate-caused extinction episodes of forests on a regional scale — the article says. — Examples we found on each of the continents where there are forests, and for different types of forests and different climatic zones. "
USFS scientists have developed measures that managers can take the natural resources to help forests and woodland ecosystems to adapt to changes caused by climate variability. "We have a whole set of techniques — said Millar — so that we do not feel helpless in the face of these changes."
Millar describes the "strategies of resistance" effects of climate change, but they may require a significant financial investment, and the results may be transient. USFS's toolset also includes "strategies" to help species to move to where their drives climate. According to Millar, managers of natural resources could, for example, to help the species of plants and animals to migrate from their native habitat, that they no longer provide support to areas where conditions are more favorable to their needs.
The third type of response to climate change, which USFS calls the "re-focusing strategy," is an attempt to bring back the collapsing ecosystems in line with natural processes, but with the expectation of the most likely climatic conditions in the future. According to Millar, these strategies are part of a broader plan USFS "to improve the sustainability of forests", especially the threat of forest fires.
In the process of photosynthesis, which occurs in the trees and other plants, carbon dioxide from the air reacts with the hydrogen from water, forming carbohydrates necessary for their growth. This process makes a significant contribution to the elimination of some of the excess carbon dioxide produced by human activity, which is considered one of the main reasons for the increase of temperature of the planet. When trees die, they not only fail to fulfill this function: wood and decaying leaves fall, becoming an additional source of carbon dioxide. Mitigating factor of the trees become a factor contributing to climate change.
In an effort to learn more about forests, the global carbon cycle and climate change, scientists — members of public services in the U.S. are also attracting attention to what benefits forests bring to humanity: providing timber, outdoor recreation, wildlife habitat and other resources that are stored and purify water, preserve the soil, and also factors of aesthetic and spiritual renewal.