A tree snag on The Preserve left standing long after the death of the oak tree. Photo by Serena Lasko.
The Ecosystem Benefits of Dead Standing Wood, or “Tree Snags”
October 26, 2022
By Andrew Nguyen, Stewardship Manager
Throughout their life cycle, trees serve as important habitat for many wildlife species, from when they are actively growing to when they’re decomposing back into the earth. Dead trees, both standing as “tree snags” and lying down as logs, provide crucial services for various birds, mammals, amphibians, insects, fungi, and countless microorganisms that process dead organic matter to enrich our soil.
Life After Death
Tree snags and logs can be:
- A Place to Live – Many animals, including birds, bats, squirrels, and wood rats make nests in hollow cavities and crevices in standing dead wood.
- A Food Source – By attracting insects, moss, lichen, and fungi, dead wood becomes a buffet for wildlife looking for a snack.
- A “Crow’s Nest” – Higher branches of snags serve as excellent look-outs from which birds like raptors and corvids can spot potential prey or other predators.
- A Hiding Place – The nooks and crannies of a snag are used by squirrels and other wildlife to store food, and are wonderful spots for reptiles and amphibians to find shade.
- A Soil Refresher – Mosses, lichen, and fungi, and billions of microorganisms invisible to the naked eye grow on snags and aid in the return of vital nutrients to the soil.
- A Fresh Start – Logs lying on the ground become “nurse logs” when seedlings sprout in the decaying organic matter, allowing new trees and understory plants to fill the space in the canopy left open by the dead tree.
Wildlife That Use Snags and Logs
While there are hundreds of wildlife species that visit tree snags from time to time, here are a few that you have likely seen hanging around dead trees on The Preserve:
1. Acorn Woodpecker – Cavity Creator
A tree snag used and then abandoned by Acorn Woodpeckers. Photo by Serena Lasko.
Acorn Woodpeckers drill new cavities in tree snags, making them primary cavity nesters. Woodpeckers excavate several nesting holes each year and rarely nest in the same one year after year, thus creating new homes for secondary cavity nesters such as squirrels, bats, swallows, and owls who cannot excavate cavities themselves and depend on other species to create space for them.
2. Red Tailed Hawk – Vigilant Hunter
A red-tailed hawk takes flight. Photo by Serena Lasko.
Raptors such as Red Tailed Hawks take advantage of taller snags to get a “birds eye view” of their hunting grounds, often oak savannas and grasslands. Lacking the canopy foliage that they sported in life, tree snags create a perfect perch to provide these birds an expansive view of their territory.
3. California Deermouse – Hidden Prey
A California Deermouse attempting to blend in with its surroundings. Photo by Alan Harper.
Life is hard for tasty prey species like the California Deermouse. Requiring places of refuge to rest and reproduce, deermice hide under downed logs to protect themselves from predators like bobcats, raptors, and coyotes. Deermice form monogamous pairs (a rarity in the rodent world), with both male and female working together to raise the young and keep the nest insulated with sticks and dry grasses.
Maintaining Wildfire Safety While Preserving Habitat
By keeping tree snags and logs on your property, you can create a refuge for your wild neighbors. Retaining these features in open areas also serves the beneficial purpose of retaining soil moisture.
To ensure that the dead wood does not pose a wildfire risk to your home on The Preserve, we recommend removing dead branches smaller than a 6-inch diameter throughout Fuel Management Zones, as outlined in your Lot-specific Fuel Management Plan (FMP).
Dead branches of at least 8 inches in diameter should remain in place if they are isolated from smaller dead materials in an open area (away from tree cover and man-made structures). Branches of this size should be moved at least 100 feet from any structure and into your Openlands if necessary. When in doubt, it is best to refer to the information about tree snags and logs in your FMP.
For more information about managing tree snags and logs on your Preserve property, please contact Stewardship Manager Andrew Nguyen at email@example.com.