Ecologists have long known that standing dead trees, commonly generally known as snags, are a vital habitat element for forest dwellers and act as drivers of biodiversity.
They're so necessary that in some managed forests, stump creation is a component of the conservation toolkit — that's, crews sometimes convert a percentage of live trees to dead trees by cutting off their tops. including injecting them with wounds to their trunks. with disease-causing fungi.
However, until now, necessary questions weren't answered: How well do any of those techniques work in the long run? And which of them are cheaper for land managers trying to expand habitat?
Jim Rivers of the Oregon State University College of Forestry checked out about 800 large-diameter Douglas-fir trees that were subjected to regeneration treatments in southwestern Oregon within the early 2000s. He learned that chain saw topping is the most effective approach to keep a decaying, standing dead tree after a few many years, especially if there are minimal live branches left rather than the highest tree.
“The key finding from this study was that there was a strong difference between the sneeze treatments in the extent of tree decline 18 to 20 years after treatment,” Rivers said. “Mechanical wounding and fungal inoculation have shown limited ability to induce forest snot and promote structural diversity. And fungal inoculation in trees that have been uprooted by chain saws is not worth the additional expense and time. It seems like the topping alone can do more than just increase the decay rate.”
In wilderness areas, debris is produced spontaneously as trees die resulting from natural causes. Some remain standing for greater than a century, providing homes and feeding grounds for voracious species.
Of particular importance amongst these species are snag-dependent woodpeckers, which act as ecosystem engineers through their foraging and nesting activities. Woodpeckers help control insects, act as indicators of forest health and create nesting cavities which can be utilized by hosts of other species.
Despite the ecological importance of snags, standing dead trees in managed forests are sometimes removed for his or her industrial value or to avoid interfering with forestry operations, particularly as they affect the protection of staff during logging. is about. In Oregon, there aren't any barriers on public or private lands.
“Snags support multiple functions within forest ecosystems,” Rivers said. “They provide vertical structure and contribute to nutrient flow and carbon cycling in addition to providing habitat for biodiversity. But many managed forests have been lost, especially to large-diameter logs.”
In this study, Rivers examined snags near Coos Bay in a pair of study sites totaling 7.5 square kilometers. Both sites are about 4 km apart.
All treatments resulted in some type of decay, but signs of decay, similar to the tree being broken, broken along the vine or peeling bark, were strongest on trees that had been chain-sawed. What was the topping experiment?
Rivers said the study illustrates that when managers enthusiastic about creating snags are deciding which treatment or treatments to make use of, they need to think when it comes to time — that's, they need recent ones to emerge. How quickly the snags are broken.
For example, if the goal is rapidly decaying — say, inside five years, creating rapid chipping in an area with little or no chipping — chainsaw topping appears to be the most effective method.
“But if the goal is to promote slow decay over longer time frames such as decades, mechanical wounds may be more appropriate,” he said. “Wounding involves the removal of a portion of the base of the tree and leads to a slow decline.”
Applying different treatments concurrently can increase the whole period during which human-created litter is out there to wildlife that rely upon dead wood — in addition to staffing the stands, Rivers added. Can reduce costs by eliminating the necessity to bring back.