We all know living trees have many benefits to humans and other creatures big and small. They take in carbon dioxide reducing the amount of greenhouse gasses in the atmosphere, and in return, provide fresh oxygen. They also support humans and wildlife by supplying shade, shelter, habitats and wood. However, what happens to trees after they die? Once a tree dies from disease, fire, storms etc., they are still extremely useful and beneficial to their ecosystem. There are two types of dead trees, snags and logs. A snag is a standing dead tree, which remains upright and decomposes naturally. When a standing dead tree or part of a tree falls to the ground, it is considered a log. Both snags and logs serve as a habitat for over 1,000 species of wildlife.
Snags are especially popular with local species of mammals, birds, insects, and even fungi. Decaying wood provides an ideal home for each of these organisms. Fungi, like mushrooms, mold and mildew, love decomposing wood and aid in making tree bark softer. Insects like, beetles, termites and ants then begin to gnaw at the brittle bark. When doing so, they are helping to break down cellulose and lignin within the bark, which is what gives wood a rigid like structure. Once the insects begin to infiltrate the tree, birds will follow shortly after. Over 25 species of birds in New Hampshire utilize snags for food and habitats. The pileated woodpecker is one example of a popular New Hampshire bird who depends on snags for the buffet of insects they provide, and cavity holes for nesting.
Logs are extremely beneficial for wildlife as well. Fallen dead trees aid in nutrient cycling within the soil and are called “nurse logs” for new seedlings. Decomposing trees release important nutrients back into the ground that help drive the nitrogen cycle, an essential element for plant growth. They also create vernal or seasonal pools, which allow organisms such as amphibians to lay their eggs. Logs serve as a refuge for small woodland animals like chipmunks seeking shelter from predators. Simple brush piles composed of sticks, twigs and bark can be extremely valuable and provide cover for wildlife as well. Rabbits, skunks, foxes, raccoons and birds hide out in backyard brush piles for safety. We need snags and logs for a healthy, functioning ecosystem. So if they are not a safety hazard, let the dead trees be, and decompose naturally for a more productive wildlife system.
-Kelsey Hanson, Staff Naturalist
