Forest restoration and salmon resilience

Salmon populations are in currently in crisis across the West, and environmental conditions are likely to pose even more challenges in the future as climate change warms waters in our streams and oceans. Access to a well-connected mosaic of quality habitat across a range of freshwater, estuarine, and marine ecosystems is necessary for Pacific salmon to complete their life cycles. Understanding the effects of climate change, along with the capacity of land management strategies to mitigate those effects, requires considering the full life cycle of salmon and accounting for changes occurring across these ecosystems simultaneously. In coastal forests of the Pacific Northwest, salmon spawning habitat is embedded within one of the most productive, biomass-rich forest ecosystems in the world. After a century of intensive timber-focused management, however, these coastal forests are in need of restoration to enhance their old-growth structural characteristics, carbon storage potential, and resilience to climate change. Forest management practices that benefit salmon habitat have long been enacted in the Pacific Northwest (e.g., retaining riparian forest buffers). However, we lack an understanding of the relative impact that forest management actions aimed at restoring forest structural complexity can achieve towards the long term population resilience of Pacific salmon populations in the context of climate change. In this project, we are addressing this challenge using an integrated population model for chum salmon (Oncorhynchus keta) in the Willapa basin (southwest Washington, USA). Using this model, we are quantifying (a) how forest management affects salmon populations within the context of climate change, and (b) the potential for land-based restoration strategies to increase the resilience of salmon populations to climate change.