MAY 01, 2014 12:00 AM PDT

Bark Beetles Kill Western Trees, Affect Mountain Streams

WRITTEN BY: Jen Ellis
Forested mountain areas throughout the western United States are suffering from the effects of bark beetles. To put the damage in perspective, the mountain pine beetle has killed off over 3 million acres of pine trees just in the state of Colorado.

Several different species of bark beetle have been infesting and ultimately killing trees, leaving the area open to fire damage and other natural consequences. A study that was recently published in the journal Nature Climate Change gauged the effect of the dead and dying trees on the surrounding mountain streams, with respect to both water flow and water quality.

A research group from the Colorado School of Mines examined the effect of the dying trees on the streams that form the headwaters of nearby rivers. They found significant effects on the water table and the corresponding flow of groundwater into nearby streams.

As trees die, they cease to participate in the water cycle. Normally, water is drawn up from the ground through the roots and distributed throughout the tree. The water eventually evaporates through the leaves/needles and re-enters the atmosphere through transpiration. With fewer trees to remove groundwater, the water table rises and a higher percentage of the groundwater enter the streams.

The team quantified the effect of the beetles by analyzing the chemistry of the water sources and comparing infested with non-infested areas. This method effectively fingerprinted the different sources and allowed the team to perform an effective mass balance on the streams and their groundwater contributions.

The study concluded that the tree deaths caused by the bark beetles contribute an extra 30% to the amount of late-summer groundwater entering the streams. Not only does this quantify the amount of excess water in the streams, but it also serves as a rough guide for how much water new trees will consume, which could assist in the eventual reforestation process.

One might think that greater water content in the streams would be a good thing in the parched West, but there are downsides. A previous study from the Colorado School of Mines detected an unusual increase in contaminants in the late summer water flows - carcinogenic contaminants from disinfectants. They were found in water treatment plants servicing the watersheds of areas infested with bark beetles.

This puts the Forest Service and the National Parks in a difficult position - how do they combat the bark beetle without aggravating other issues such as water quality, and the potential for runoff and flood damages?

For example, while the recent massive flooding in north-central Colorado near Rocky Mountain National Park was caused by virtually unprecedented rains, the damage that the bark beetle has done certainly did not help the situation.
While the war against the bark beetle rages on, this study provides a template on how to quantify the effects - and hopefully before long it will be able to confirm that the war is won and that the water quality and groundwater levels are returning to normal. Otherwise, we may be in danger of permanent damage of some of our treasured National Parks.
About the Author
You May Also Like
JUN 29, 2021
Earth & The Environment
Are Hydropower Plants as Green as They Seem?
JUN 29, 2021
Are Hydropower Plants as Green as They Seem?
Hydroelectric plants are touted for their ability to provide so-called green energy, which aims to continue to satisfy d ...
JUL 11, 2021
Earth & The Environment
A Lake in Antarctica Suddenly Drains
JUL 11, 2021
A Lake in Antarctica Suddenly Drains
During the winter of 2019, a large and deep lake on the Amery Ice Shelf in East Antarctica was lost in about a week. Abo ...
JUL 15, 2021
Space & Astronomy
Modern Slavery in Greece Spotted from Space
JUL 15, 2021
Modern Slavery in Greece Spotted from Space
Migrant settlements being exploited for work have been spotted with satellite imagery by researchers led by the Universi ...
JUL 22, 2021
Earth & The Environment
Great Lakes Fish Contain Record Levels of Microplastics
JUL 22, 2021
Great Lakes Fish Contain Record Levels of Microplastics
A new study published in Conservation Biology reports the highest ever concentration of microplastics concentrating in d ...
AUG 26, 2021
Health & Medicine
Hoover Dam is going dry: Water shortage declared for the first time ever in the USA
AUG 26, 2021
Hoover Dam is going dry: Water shortage declared for the first time ever in the USA
We have all heard of the famous “bathtub ring” around Lake Mead (AZ, MN) and many have seen photos and video ...
SEP 07, 2021
Plants & Animals
All dogs may be descended from the same 23,000-year-old Siberian ancestor
SEP 07, 2021
All dogs may be descended from the same 23,000-year-old Siberian ancestor
New research suggests that all modern dogs are descended from the same 23,000-year-old Siberian ancestor
Loading Comments...