Can Trees Cause Pollution?

In a recent study it was shown that mountain pine beetles may be contributing to haze and air pollution in western forests. In our area there are pine beetles, ips beetles, and other bark boring insects that attack east coast trees; Can beetles in our area also contribute to haze and air pollution? Local Forest Service personnel say yes, however, that’s the least of our worries when it comes to these pests. The bigger problem? The loss of these trees from our forests and landscapes. “It has been shown that beetle-infested trees are capable of releasing up to 20 times more organic substances than non-infested trees. These organic substances come in many varieties and trees release these organic compounds to fight the beetles that bore into the trees’ bark”. It’s kind of like the tree’s immune system. According to researchers, these compounds not only help the tree fight the invaders, they also produce a haze that may harm human health, reduce visibility and affect climate. Though increased haze may obscure some nice vistas and views of scenic sites, what concerns Arborists and trees experts more is stopping the spread of these insects and preventing those green trees from turning into brown forests.

Preventing bark beetle spread is the main focus. As pointed out in the study, “one infested tree can lead to eight to 10 other trees being infested the following year, which causes a problem that grows exponentially”. There are other side effects of the beetles that are also a concern for foresters and landscape managers as well as golf course officials and others: “There’s the social impact of having all these dead trees, there’s the economic impact of losing the important ornamental beauty of our parks and golf courses, and there is the value of all these dead trees that we’re losing from a timber standpoint”. But it certainly is an area of new research into the effect of pine beetles that shows that there is more than just a few dead trees. It also shows that pollution and global warming concerns are not just cars and factories.

What are Bark Beetles and Borers? Borers and bark beetles are common pests of pines. These pests are highly damaging because they feed under the tree bark. Pines that become stressed by drought or root damage are often rapidly killed by these pests. Pines at highest risk of these pests are those with root damage or bark injuries. Unfortunately, infestations may not be discovered until advanced symptoms appear, which include yellowing of the needles, holes in the bark that exude sap or sawdust, and emergence holes of the borers through the bark. Here are some things you can do to help with these insects - Plant healthy trees and pick species that adapt best to our area (Remember the Maxim - Right Tree, Right Place). Avoid injuries to roots and trunks and soil compaction during construction activities. Make sure you water your trees! Irrigate when appropriate around the outer canopy and not just near the trunk. Be sure to water at least twice a month during drought periods. As always, properly prune your trees and dispose of dying trees so that these pests do not emerge and attack other nearby trees.

Mostly, it’s as easy as right tree, right place and general TLC to keep opportunistic pests such as bark beetles from damaging your trees and the environment.