An invasion is killing trees across the country. A small speck seems to be nothing that looks like a killer, but when the little beetles spread to epidemic levels the results are devastating.
There are 600 species of bark beetles in the United States but as climate change prevails certain species are expanding their range and growing in the millions causing an epidemic on trees.
One of these species — the mountain pine beetle — has killed nearly 100,000 square miles of trees across western North America over the past 20 years, affecting 18 million hectares of pine forest. The beetles eat a path through the bark and lay their eggs and a single mating pair can reproduce more than 12 million beetles a year.
The beetles weren’t always bad. Until recently the beetles played a pivotal role helping balance the ecosystem. Bark beetles broke down older and weak trees ultimately leading to healthier forests.
But as C02 levels change our climate at a rapid pace, drier conditions and droughts have caused a domino to fall in this precise balance leaving even healthy trees open to be attacked by their spread.
A single domino can’t fall without hitting another. Trees break down and rot, creating less habitat for wildlife as it provides little canopy cover or more blowdown. An increase in fallen trees hinders the ability of wildlife movement, increasing the energy they spend when moving throughout their territories.
It also affects timber production for houses and buildings and helps contribute to growing wildfire seasons across the country. This outbreak increases the severity of wildfires causing firefighters to observe erratic fire behaviors in bark-beetle-affected forests.
Despite these observations, the U.S Forest Service says there still isn’t a clear understanding of how bark beetle outbreaks affect wildfires. Increased CO2 levels are the catalyst that caused these invasions, but the beetles are also contributing to the carbon dioxide released into our atmosphere.
Trees serve as carbon sinks, meaning they absorb more carbon than they release which in turn lowers the concentration of CO2 in the atmosphere. According to NASA, approximately 2.6 billion tons of carbon dioxide (CO2) -- one-third of the CO2 released from burning fossil fuels -- is absorbed by forests every year.
So not only is climate change a driving factor in the epidemic of these bark beetles. The bark beetles that are killing the trees are releasing tons of carbon dioxide back into the atmosphere.
Restoration efforts emphasizing diversity are considered viable management strategies in this battle.