Wednesday, October 16, 2013

Impact of Various Timber Harvesting Practices on Songbirds

Hooded Warbler
I wanted to share the research project with my readers.  It is certainly applicable to Pennsylvania with the big push in the state to create early successional and young forest habitat.  A research paper was recently published in the journal Forest Management and Ecology.  The article is entitled Long-term response to disturbance-associated birds after different timber harvests.  The research was conducted by Roger Perry and Ronald Thill both from the US Forest Service Southern Research Station.  The authors looked at changes in early successional bird abundances of 12 species for 16 years after harvest under 4 regeneration methods.  These included: clearcutting, shelterwood, single-tree selection, and group-selection harvests.

Here are some of the highlights of their research findings:
1. Detection rates generally peaked 5 years after harvest.
2. Clearcuts retained some species for longer periods than other treatments.
3. Some species benefitted more from partial harvesting than clearcutting.
4. Greater expanses of partial harvests may be needed to sustain population levels similar to those 
    found in clearcuts.
Timber harvest provides favorable habitat for many species of shrub-dependent birds. Because of historical dominance, effect of clearcutting on early successional birds has been widely studied, but less information is available on alternatives such as shelterwood and group selection, which have become a more dominant means of regenerating pines (Pinus spp.) on federal lands of the southeastern US. We compared detection of 12 species of early successional forest birds prior to harvest and at various intervals for 16 years after harvest in stands subjected to clearcutting, shelterwood, single-tree selection, and group-selection harvests. We also compared detection rates of these species between harvested and unharvested control stands.
To read the full abstract and view some of the tables click here.

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