PNNL

Abstract

Forest landscapes offer resources and ecosystem services that are vital to the social, economic, and cultural well-being of human communities, but capturing and maintaining these provisions can lead to socially and ecologically relevant trade-offs. We designed a spatial decision support model to reveal trade-offs and synergies in management of a large eastern Cascade Mountain landscape in Washington State, USA. We used process-based forest landscape (LANDIS-II) and hydrology (DHSVM) models to compare outcomes associated with 100 yr of simulated forest and wildfire dynamics for two management scenarios, Wildfire only and Wildfire + Treatments. We then examined the amounts and spatial distributions of potential treatment effects and trends in a set of resources and ecosystem services over the simulation period. Wildfire area burned increased over time, but some impacts could be mitigated by adaptation treatments. Treatment benefits were not limited to treated areas; instead, we observed neighborhood benefits, where fire spread and severity were reduced not only in treated patches but in adjacent patches and landscapes. Furthermore, neighborhood effects on nearby untreated areas allowed for synergies among some resource benefits and services. Ordinations provided further evidence for two main kinds of outcomes. Positive ecological effects of treatments were greatest in upper elevation moist and cold forests, while positive benefits to human communities were aligned with drier, low and mid-elevation forests closer to the wildland urban interface (WUI). Our results contribute to improved understanding of synergies and tradeoffs linked to adaptation and restoration efforts in fire-prone forests and can be used to inform management aimed at rebuilding resilient, climate-adapted landscapes.