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  • Effects of Thinning on Forest Structure important to the recovery of ESA-listed species


Northwest Fisheries Science Center (NWFSC) Fish Ecology FE - Watershed


Forest thinning
Effects of Thinning on Forest Structure important to the recovery of ESA-listed species
This study evaluates the effects of thinning regimes designed to accelerate the development of late-successional forest structure for the benefit of salmon and other ESA-listed species. The focus is to ensure that proposed thinning activities (primarily by federal agencies such as BLM and USFS) do not delay the recovery of habitat important to these ESA-listed species. Currently thinning actions undertaken by BLM and USFS have resulted in the substantial delay in the recovery of instream habitat. The results from this study are intended to be provided to these agencies so that they can make management decisions consistent with the restoration and recovery of habitat important to ESA-listed species, in particular, instream habitat.

Research Themes

Habitats to support sustainable fisheries and recovered populations
Healthy oceans, coastal waters, and riverine habitats provide the foundation for aquatic resources used by a diversity of species and society. Protecting marine, estuarine and freshwater ecosystems that support these species relies on science to link habitat condition/processes and the biological effects of restoration actions. The NWFSC provides the habitat science behind many management actions taken by NOAA Fisheries and other natural resource agencies to protect and recover aquatic ecosystems and living marine resources. The NWFSC also maintains a longstanding focus on toxic chemical contaminants, as a foundation for regional and national research on pollution threats to fisheries and protected resources.

Research Foci

Characterize relationships between habitat and ecosystem processes, climate variation, and the viability of organisms
Developing effective conservation and restoration strategies for species or populations requires a clear understanding of how ecosystem processes and climate change will influence the viability of organisms in the future. Key research needs include (1) evaluating the vulnerability of organisms and ecosystems to climate change and human impacts (e.g., fishing, pollution, land use), and (2) devising adaptation strategies that will help achieve conservation goals despite climate change and increasing human pressures. Understanding how climate change or trends in human impacts might influence organisms is based on an understanding of linkages between ecosystem processes, habitat conditions, and abundance, survival or demographics of organisms. This necessitates modeling influences of ecosystem processes on habitats and species, or developing models to examine influences of human pressures on population or ecosystem dynamics. With this foundation, vulnerability assessments can focus on understanding how interactions between climate change and human impacts influence vulnerability of species or populations. Adaptation strategies require knowledge of current conservation needs, predictions of how those needs might change as a result of climate change or future human impacts, and assessments of the robustness of alternative conservation strategies or techniques to climate trends.
Develop effective and efficient habitat restoration and conservation techniques
Maintaining and re-establishing viability and sustainability of living marine resources requires conservation and rehabilitation or restoration of habitats upon which species depend. Common habitat restoration approaches and tech-niques often presume that habitats are static features of the environment, and that creation of stable habitats is a desirable restoration strategy. However, riverine, nearshore, and marine habitats are created and sustained by dynamic landscape, climatic, and oceanographic processes and biota are adapted to changing habitats that are within the range of natural variability. Hence, current restoration strategies often have limited success, in part because they fail to recognize larger scale processes that drive habitat change, and in part because they fail to recognize intrinsic habitat potential of individual restoration sites. The main goals of this research focus are to: improve understanding of how large-scale processes create diverse and dynamic habitats that support marine and anadromous species, better understand how human activities alter habitat-forming processes and habitats, develop new restoration techniques that are compatible with sustainable habitat-forming processes, and understand the variety of actions needed to adequately conserve intact critical habitats. In addition, NWFSC’s research will improve understanding of how new and existing habitat restoration and protection techniques affect fish and habitat at multiple scales (i.e., reach, watershed, Evolutionarily Significant Unit).


regulatory law
forest thinning
selective removal of trees, primarily undertaken to improve the growth rate or health of the remaining trees
all salmonids


None associated


Pseudotsuga menziesii
Thuja plicata
Tsuga heterophylla
Genus Oncorhynchus
Genus Salvelinus
Kingdom Plantae


Michael Pollock
Principal Investigator