A dying tree. (Rowan Gillette-Fussel/Flickr Creative Commons)
The Research column will be a weekly feature on the scientific opportunities on campus written by staff writer Diler Haji.
By now the world is more or less aware of the impending threats of a changing global climate. The specific details of how these changes will affect the biological systems all around us, however, is largely unknown. If you’re reading this, you probably live in the northeast U.S. and probably go to the University of Connecticut, a large rural campus covered in trees and bordered by forests.
What, you may wonder, will happen to these forests as decades of global warming change the environment in which these trees have evolved and adapted? What will happen to trees across the country? Can these trees keep up with the rapid changes our societies are inflicting through fossil fuels and other acts of environmental degradation?
It just may be that trees will die off much quicker than we expect and the process by which that could happen is something akin to what we think of as a heart attack.
A recent study published this year in the Proceedings of the National Academy of Sciences looked at 33 studies of tree death, including 475 species of trees across the world. The study concluded that the hydraulic systems pushing water through trees are at high risk as drought-like conditions become more intense and common.
When trees fight to push what little water they can through their tiny conduits, they run the risk of clogging those conduits with air pockets. This causes an embolism, sort of like a blood clot in the coronary artery supplying blood to your heart and causing a heart attack. Warmer and drier conditions also make the walls of the conduits malleable, as if they were melting, which increases the chance that the walls will cave into the air pockets and ruin the crucial water-pumping system the tree needs to survive.
This was already observed in another study published in New Phytologist in 2012 exploring the risks to balsam poplar trees after forest fires, when conditions are extremely hot and dry. In this case, the study found that increased heating caused deformations in water-conduit walls and significantly lowered the flow of water through the plant, potentially killing key parts of the tree.
Affects like these are not obvious, which makes predicting how the world will change in the next few decades and centuries monumentally difficult. Before, it was thought that the die-off of tree stems kept key nutrients made in the leaves of plants from traveling to the rest of plant. However, the latest research shows that plants face an even higher risk when it comes to transporting water.
With more research, greater light will hopefully be shed on the fine-grained implications of changing climates around the world, but even with this knowledge, the massive connections and interactions found in nature are bottomless.
When it comes to tree “heart attacks,” there is a cause for concern and a reason to reverse the environmentally irresponsible habits our society has grown comfortable with. Not only are the beautiful northeastern forests all around us here at UConn at risk, but also the forests of the western U.S., which are increasingly experiencing larger and more common forest fires.
Dead trees will only provide more material for fires to ignite and grow. While climate change could increase tree death as a result of embolisms, many other threats are still looming. For example, wood-boring beetles will only expand their territories, growing more abundant as the climate warms. These beetles kill trees and could both increase material that feeds forest fires and change the balance of tree species in the ecosystems they inhabit.
Diler Haji is a staff writer for The Daily Campus and can be reached via email at diler.haji@uconn.edu.