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Impacts of the northwest forest plan on forest composition and bird populationsAuthor(s): Benjamin T. Phalan; Joseph M. Northrup; Zhiqiang Yang; Robert L. Deal; Josée S. Rousseau; Thomas A. Spies; Matthew G. Betts
Source: Proceedings of the National Academy of Sciences. 101: 201813072-.
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
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DescriptionThe Northwest Forest Plan (NWFP) initiated one of the most sweeping changes to forest management in the world, affecting 10 million hectares of federal land. The NWFP is a science-based plan incorporating monitoring and adaptive management and provides a unique opportunity to evaluate the influence of policy. We used >25 years of region-wide bird surveys, forest data, and landownership maps to test this policy’s effect on biodiversity. Clearcutting decreased rapidly, and we expected populations of olderforest– associated birds to stabilize on federal land, but to continue declining on private industrial lands where clearcutting continued. In contrast, we expected declines in early-seral–associated species on federal land because of reduced anthropogenic disturbance since the NWFP. Bayesian hierarchical models revealed that bird species’ population trends tracked changes in forest composition. However, against our expectations, declines of birds associated with older forests accelerated. These declines are partly explained by losses of older forests due to fire on federal land and continued clearcutting elsewhere. Indeed, the NWFP anticipated that reversing declines of older forests would take time. Overall, the early-seral ecosystem area was stable, but declined in two ecoregions—the Coast Range and Cascades—along with early-seral bird populations. Although the NWFP halted clearcutting on federal land, this has so far been insufficient to reverse declines in older-forest–associated bird populations. These findings underscore the importance of continuing to prioritize older forests under the NWFP and ensuring that the recently proposed creation of early-seral ecosystems does not impede the conservation and development of older-forest structure.
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CitationPhalan, Benjamin T.; Northrup, Joseph M.; Yang, Zhiqiang; Deal, Robert L.; Rousseau, Josée S.; Spies, Thomas A.; Betts, Matthew G. 2019. Impacts of the northwest forest plan on forest composition and bird populations. Proceedings of the National Academy of Sciences. 101: 201813072-. https://doi.org/10.1073/pnas.1813072116.
KeywordsBird population trends, public policy, avian conservation, old-growth forests, early-successional ecosystems.
- Synthesis of science to inform land management within the Northwest Forest Plan area
- Landscape context for density management: implications of land ownership and ecological gradients
- Northwest Forest Plan–the first 20 years (1994-2013): status and trends of late-successional and old-growth forests
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