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what Will be increasingly difficult to find a good shade under the branches? Climate change is causing changes undeniable on the planet, including the size and age of the trees, according to new research published in the journal “Science”. The specimens, say the scientists, are becoming increasingly small and young, which has extensive impacts on global ecosystems.
The researchers, led by the National Laboratory the Pacific Northwest (PNNL) of the u.s. Department of Energy EE. UU., they believe that these alterations, which occurred during the last century, are caused by the increase of the temperature and of the carbon dioxide, and the frequency and severity of disturbances such as forest fires, drought, damage by wind and other natural enemies. These factors, combined with forest harvesting, which have led to a strong decrease in the age and the stature of the forests.
Fires and droughts
As they explain, the highest levels of carbon dioxide in the atmosphere, which have risen dramatically since the Industrial Revolution, can increase the rate of growth of a tree and the production of seeds. However, such fertilization only occurs in forests more young people with abundant nutrients and water. This is not the case in most of the world’s forests, which significantly reduces the benefits of carbon dioxide for the trees.
at The same time, the increase of the temperature limited photosynthesis, which gives life, which leads to slower growth, increased mortality and reduced regeneration. This is one of the causes that the trees are lower. For its part, the droughts, whose frequency, duration, and severity will increase at the global level, may directly cause the death of the tree or, indirectly, lead to mortality due to the attack of insects or pathogens.
Other factors that alter the forests are the forest fires. Not only are increasing, but that in the future may be more frequent than they have been in the last 10,000 years in some regions, according to the study. The growth of plants after forest fires may be slow or not happen due to the high temperatures. Also they have increased the pests. The carbon storage lost by insects every year is the same as the amount of carbon emitted by 5 million cars, according to a study published last year. This is expected to continue with warming, along with other disorders such as bacteria and fungi. In the tropics, the vines use other plants as structures guest smother trees to death.
Finally, the logging industry has reduced the amount of forests and the ancient forests around the world. When forests are restored in the land to be harvested, the trees are smaller and it reduces the biomass.
A different planet
All this you paid a bill very expensive, since it “involves the reduction of the forests in their capacity to store carbon, and changes potentially large in the mix of species that make up and inhabit these forests”, says Tom Pugh, of the Forest Research Institute of Birmingham (BIFoR).
And worst of all, according to the researchers conclude, is that it is likely that this trend will continue due to the warming climate. Unfortunately, all the factors related to mortality forest will increase in frequency and severity over the next century, say the authors. Make a warning: “A future planet with less forests, large and old will be very different from what we are accustomed”.