Dead wood. Sorry, not the HBO TV series commentary you were expecting, but stay tuned…”the benefits of dead wood” will keep you on the edge of your seat.
Most people like their landscapes to look neat, groomed and maintained.
We spend hours trimming, mowing, weeding, and raking our gardens to achieve the manicured look. This look and behavior has also become visible in our parks and along our creeks. Unfortunately, changes in the landscape resulting from over mowing, agriculture, and development have altered creekside forest environments, which, in turn, changed the physical and biological characteristics of our creeks.
Trees that grow along lakes and creeks sometimes fall into water due to floods, erosion, wind, disease, or natural mortality. Wood, in the form of tree trunks, large logs, and tree roots provide important biological and physical benefits for streams.
When large woody debris might pose a threat of flooding in urban environments then Watershed Protection’s Field Operations crews remove it. However, when possible, woody debris is left in place to benefit the health of the lake and creek ecosystems.
Ecological benefits of dead wood
Dead wood in creeks provides habitat, food, and protection for fish and other aquatic organisms. Logs help carve out pools (deep, slow moving section of creek) which provides a nursery for fish and recreational benefits for humans. The life histories of more than 85 species of fish have some association with large wood for cover, spawning (egg attachment, nest materials), and feeding. Many other aquatic organisms, such as crayfish, certain species of freshwater mussels, and turtles, also depend on large wood during at least part of their life cycles. In riparian areas, snags and laying dead wood provide wildlife habitat, release nutrients as they slowly decompose, and improve the ability of the soil to retain water.
Fungi and mushrooms flourish on and around logs, breaking down the organic matter to slowly release important nutrients back into the ecosystem. The decaying logs retain moisture and nutrients that aid in plant growth so areas around the logs are nurseries for young plants.
The twinkling of fireflies at dusk is a sign that summer has arrived and brings back cherished memories to many kids chasing them around the garden. Firefly larvae live in rotting wood and leaf litter near water. Lightning bug populations decline as their woody habitat decreases. Join Firefly Watch to team up with researchers and other volunteers to document these magical insects.
Look for these stencils on woody debris in Austin parks to inform City staff and contractors that the tree should not be removed.
Dead wood improves streambank stability
Wood in creeks reduces bank erosion and sediment transport. Large woody debris creates blockages that allow for a more natural meandering stream shape, improving storage and building bed sediments. Watch a video for an explanation of stream stability.
How to Help
- Leave tree trunks, large logs, and tree roots in creeks or riparian areas
Create dead wood habitat in low areas in your yard where decomposition and soil building can occur
Commend park staff on standing dead trees and fallen branches left in natural areas
- Encourage your neighborhood and local parks activists to document and maintain standing and down wood in park and natural areas.
Establish tree islands under dead trees to promote new tree growth. Tree islands are areas where mowing is eliminated near a dead tree so younger trees and vegetation can grow up while the dead tree continues to provide valuable ecological services. (Contact Staryn Wagner for more information: firstname.lastname@example.org).
Fencing around a newly established tree island.