Spruce Trees and Spruce Beetles: A Lethal Combination for Northern Forests?

Spruce trees are a staple of northern forests, providing habitat for wildlife, contributing to the carbon cycle, and supporting the livelihoods of many people. However, spruce trees are increasingly under threat from spruce beetles. Here’s why spruce beetles are thriving and the impact it’s having on northern forests.

How are Spruce Beetles Killing Spruce Trees?

Unlike woolly adelgids that are to blame for large-scale hemlock tree losses, spruce beetles are native to North America and feed on the inner bark of spruce trees, which can weaken and eventually kill the trees. In addition, they can speed up the trees death by bringing a fungus that prevents water from being transported throughout the tree.

The Cause of an Increase of Spruce Beetle Outbreaks

The combination of black spruce trees and spruce beetles is a lethal one for northern forests. Spruce beetle outbreaks have been increasing in frequency and severity, with devastating consequences for forest health and the people and animals that depend on it.

A Forest Health Protection Report describes the findings of an aerial survey in 2016: 190,000 acres of damage were caused by spruce beetles - a nearly 500% increase from the previous year.

Usually, the spruce beetle population is kept in check by natural predators, competition for resources, and cold temperatures. However, when temperatures rise and drought occurs, the spruce beetle population can explode, leading to widespread infestations. Warmer and drier summers caused by climate change alter the life cycle of spruce beetles, plus the impact of drought on black spruce trees makes them more unlikely to be able to survive an attack. Warm and dry summers coupled with warmer winters will allow more beetles to survive through the winter.

The Impact of Spruce Beetles Killing Spruce Trees

A paper released by scientists in 2022 issued the warning that tree extinctions will result in catastrophe.

The more spruce trees that die, the bigger the impact on the environment:

• The higher the risk and potential severity of wildfires.
• Animals may have to find new habitats and sources of food.
• Increased safety risk from large numbers of potentially falling trees.
• Economic losses.

How to Protect Spruce Trees from Spruce Beetles

So, what can be done to protect spruce trees and northern forests from spruce beetles?

Forest management is an important strategy. Practices such as thinning and prescribed burning can help to create a more resilient forest ecosystem that is better able to withstand spruce beetle outbreaks. Monitoring for spruce beetle infestations and taking swift action to remove infested trees can also help to limit the damage caused by spruce beetles. According to the National Park Service, the US Forest Service’s Forest Health Protection Program and Alaska Department of Natural Resources, Division of Forestry, monitor forest health throughout the state.

Tackling the root cause of spruce beetle outbreaks is another important strategy, and one that we can all be involved in. Helping to slow down climate change will reduce the likelihood of more severe spruce beetle outbreaks from taking place.

The consequences of spruce beetle infestations can be devastating, affecting everything from forest health to local economies. By understanding the relationship between spruce trees and spruce beetles, and taking action to reduce the impact of climate change, plus monitoring and managing forests, it's hoped spruce beetle outbreaks can be managed. Shop all our hand-drawn tree designs today, including our Black Spruce Collection, and we'll fund the planting of trees, plus donate to ecological nonprofits including National Forest Foundation.