A new study on the fate of trees in a warming planet suggests that major changes are already in the works as to how forests are adjusting to climate change.
In a paper published Wednesday in the journal Nature, scientists suggest that thrifty trees are becoming more efficient and doing more with less. They are extracting less water out of the ground to achieve the same amount of growth.
Scientists involved in this study said the only likely explanation for this trend is that because of the rising levels of carbon dioxide in the air, leaves on plants are able to close their pores or stomata and still get plenty of the gas they need. This shutting down of pores results in the reduction of evaporation of water from the leaf, which in turn causes the tree to draw less water out of the ground.
This phenomenon, according to scientists, has potential benefits for the plants. It suggests that trees are exhibiting signs of becoming more resilient and becoming thriftier as temperatures rise and droughts are on the increase around the world.
However, experts also caution that there is a downside to this trend and what consequences this development is likely to have on human and ecological systems that hinge on the current patterns of moisture flow for survival.
Speaking of the new finding, the principal scientist, Dr. Trevor F. Keenan of Macquarie University in Sydney in Australia said, “We’ve examined the trend upside down and inside out as much as we can, and it is wholly robust.”
He stressed, however, that more research needs to be done to prove that that is the correct explanation.
Several scientists not involved in this study also said more efforts are needed to clarify if the trees are indeed using less water and what inferences can be drawn regarding the effect this might have on the ecological balance of the planet.
One scientist predicted that the downside could result in less water that trees pull out of the ground, the less water they supply to farming areas. The enormous amount of water trees pull out of ground is dissipated as moisture in the atmosphere. This helps supply moisture to farming areas that lie downwind of forests.
So if trees use less water, this means crops in some regions of the world will have no rain and no water to allow them to thrive.
Previous studies have suggested that climate change is having a mixed effect on forests depending on their locations. Research has found big wildfires are on the increase around the globe. Thomas Tidwell, the head of the US Forest Service, told a Senate Committee recently that fire season now lasts two months longer and destroys twice as much land it did four decades ago.
The devastation caused by forest fires extends worldwide from Africa to Australia. Reports say that great euphorbia trees of southern Africa are surrendering to heat and water stress as are the Atlas cedars of northern Algeria.
In Siberia, fires have destroyed large stretches of the Siberian forest. In Australia, eucalyptus trees are succumbing in a large scale to heat. According to reports, the Amazon recently endured two “once a century” droughts only five years apart, destroying many large trees. In central Rockies millions of pines have died due to causes related to climate change.
Recent reports say in western Montana, show evergreen trees are being destroyed by beetles that were once upon a time controlled by cold winter temperatures. Scientists say that control is no longer occurring because of warming temperatures.
On the other hand, in other areas, according to researchers, forests are thriving because rising carbon dioxide is essentially acting as a plant fertilizer.
Experts do not know how these two conflicting trends will balance out. They are struggling to understand the situation and understand how it will play out. They surmise that our future survival on this earth may depend on the answer.
By Perviz Walji