Divergent trends in ecosystem services under different climate-management futures in a fire-prone forest landscape

While ecosystem services and climate change are often examined independently, quantitative assessments integrating these fields are needed to inform future land management decisions. Using climate-informed state-and-transition simulations, we examined projected trends and trade-offs for a suite of ecosystem services under four climate change scenarios and two management scenarios (active management emphasizing fuel treatments and no management other than fire suppression) in a fire-prone landscape of dry and moist mixed-conifer forests in central Oregon, USA. Focal ecosystem services included fire potential (regulating service), timber volume (provisioning service), and potential wildlife habitat (supporting service). Projections without climate change suggested active management in dry mixed-conifer forests would create more open forest structures, reduce crown fire potential, and maintain timber stocks, while in moist mixed-conifer forests, active management would reduce crown fire potential but at the expense of timber stocks. When climate change was considered, however, trends in most ecosystem services changed substantially, with large increases in wildfire area predominating broad-scale trends in outputs, regardless of management approach (e.g., strong declines in timber stocks and habitat for closed-forest wildlife species). Active management still had an influence under a changing climate, but as a moderator of the strong climate-driven trends rather than being a principal driver of ecosystem service outputs. These results suggest projections of future ecosystem services that do not consider climate change may result in unrealistic expectations of benefits

Fire severity and vegetation response to fire in riparian areas of the Biscuit and B&B Complex Fires, Oregon

Fire is the dominant disturbance process in western U.S. forests, and although effects of fire in upland forests are relatively well-studied, there is little information about fire effects on riparian forests, critical areas of the landscape for both habitat and water quality. This dissertation examines different aspects of fire effects in riparian areas of two recent fires in Oregon, the Biscuit Fire in southwestern Oregon and the B&B Complex Fire in the Cascade Mountain Range. In the first of three studies, I compared riparian fire severity to that in uplands and investigated factors influencing riparian fire severity in both fire areas. In a second study, the relationships among ground-based indices of fire severity in riparian areas, and the relationships between ground-based and remotely-sensed indices of fire severity, were examined. In a third study, I investigated patterns in post-fire riparian plant community regeneration in the same areas. I found that understory fire severity was significantly lower in riparian areas compared to adjacent uplands, suggesting a decoupling of understory fire effects in riparian areas versus uplands. However, there were no differences in overstory fire severity between riparian areas and uplands in either fire. Understory and overstory fire severity indices were found to be weakly related, suggesting that there are limitations in the use of both types of fire severity indices. However, both overstory and understory fire severity in riparian areas were most strongly predicted by upland fire severity. Riparian fuel properties were also strong predictors of riparian fire severity. Patterns in post-fire riparian regeneration were influenced, at a coarse spatial scale, by factors associated with position in a watershed (headwater versus main stem channels) in the Biscuit Fire and by elevation/plant association in the B&B Complex Fire. At a finer spatial scale, differences in species composition and microsite conditions between deciduous hardwood- and conifer-dominated communities, and understory fire severity, influenced patterns of post-fire regeneration. Results of these studies suggest that management practices that reduce upland fire severity may also reduce riparian fire severity. Results also suggest that post-fire riparian regeneration efforts be tailored to site-specific vegetation conditions of complex riparian environments

Adapting to the effects of climate change on natural resources in the Blue Mountains, USA

National forests in the Blue Mountains (USA) region have developed adaptation options that address effects identified in a recent climate change vulnerability assessment. Adaptation strategies (general, overarching) and adaptation tactics (specific, on-the-ground) were elicited from resource specialists and stakeholders through a workshop process. For water supply and infrastructure, primary adaptation strategies restore hydrologic function of watersheds, connect floodplains, support groundwater-dependent ecosystems, maximize valley storage, and reduce fire hazard. For fisheries, strategies maintain or restore natural flow regimes and thermal conditions, improve water conservation, decrease fragmentation of stream networks, and develop geospatial data on stream temperature and geologic hazards. For upland vegetation, disturbance-focused strategies reduce severity and patch size of disturbances, protect refugia, increase resilience of native vegetation by reducing non-climate stressors, protect genotypic and phenotypic diversity, and focus on functional systems (not just species). For special habitats (riparian areas, wetlands, groundwater-dependent ecosystems), strategies restore or maintain natural flow regimes, maintain appropriate plant densities, improve soil health and streambank stability, and reduce non-climate stressors. Prominent interactions of resource effects makes coordination critical for implementation and effectiveness of adaptation tactics and restoration projects in the Blue Mountains. Keywords: Adaptation strategies, Adaptation tactics, Climate change, Restoration, Stressor

Climate Change Vulnerabilities and Adaptation Options for Forest Vegetation Management in the Northwestern USA

Recent vulnerability assessments, conducted in diverse regions in the northwestern United States, indicate that many commonalities exist with respect to projected vulnerabilities to climate change. Dry forests are projected to have significant changes in distribution and abundance of species, partially in response to higher temperature and lower soil moisture, but mostly in response to projected increases in extreme events and disturbances—drought, wildfire, and insect outbreaks. Wildfire and mountain pine beetles have caused extensive mortality across millions of hectares in this region during the past decade, and wildfire area burned is projected to increase 200%–300% by mid-21st century. Science–management partnerships associated with recent assessments have identified an extensive list of adaptation options, including both strategies (general planning) and tactics (on-the-ground projects). Most of the options focus on increasing resilience to disturbances and on reducing current stressors to resource conditions. Adaptation options are generally similar across the biogeographically diverse region covered by assessments, suggesting that there may be a limit on the number of feasible responses to climate change. Federal agencies in the northwestern United States are now using these assessments and adaptation approaches to inform sustainable resource management and planning, mostly through fine tuning of existing practices and policies

Data from: Climate change, wildfire, and vegetation shifts in a high-inertia forest landscape: Western Washington, U.S.A.

Future vegetation shifts under changing climate are uncertain for forests with infrequent stand-replacing disturbance regimes. These high-inertia forests may have long persistence even with climate change because disturbance-free periods can span centuries, broad-scale regeneration opportunities are fewer relative to frequent-fire systems, and mature tree species are long-lived with relatively high tolerance for sub-optimal growing conditions. Here, we used a combination of empirical and process-based modeling approaches to examine vegetation projections across high-inertia forests of Washington State, USA, under different climate and wildfire futures. We ran our models without forest management (to assess inherent system behavior/potential) and also with wildfire suppression. Projections suggested relatively stable mid-elevation forests through the end of the century despite anticipated increases in wildfire. The largest changes were projected at the lowest and uppermost forest boundaries, with upward expansion of the driest low-elevation forests and contraction of cold, high-elevation subalpine parklands. While forests were overall relatively stable in simulations, increases in early-seral conditions and decreases in late-seral conditions occurred as wildfire became more frequent. With partial fire suppression, projected changes were dampened or delayed, suggesting a potential tool to forestall change in some (but not all) high-inertia forests, especially since extending fire-free periods does little to alter overall fire regimes in these systems. Model projections also illustrated the importance of fire regime context and projection limitations; the time horizon over which disturbances will eventually allow the system to shift are so long that the prevailing climatic conditions under which many of those shifts will occur are beyond what most climate models can predict with any certainty. This will present a fundamental challenge to setting expectations and managing for long-term change in these systems

US strategy for forest management adaptation to climate change: building a framework for decision making

International audience& Context Recent policy changes in the USA direct agencies managing federal forests to analyze the potential effects of climate change on forest productivity, water resource pro-tection, wildlife habitat, biodiversity, and other values. & Aims This paper describes methods developed to (1) as-sess current risks, vulnerabilities, and gaps in knowledge; (2) engage internal agency resources and external partners in the development of options and solutions; and (3) manage forest resources for resilience, not just in terms of natural ecosystems but in affected human communities as well. & Methods We describe an approach designed to character-ize certain climate change effects on forests, and estimate the effectiveness of response options ranging from resis-tance to a realignment of management objectives. & Results Field testing on a 6,300 km 2 area of conifer forest in the northwestern USA shows this decision model to be useful and cost-effective in identifying the highest sen-sitivities relating to vegetation management, biological diversity, water resources and forest transportation sys-tems, and building consensus for adaptive strategies and actions. & Conclusions Results suggest that this approach is an effec-tive means for guiding management decisions to adapt to the effects of climate change, and provides an empirical basis for setting budgetary and management priorities

Appendix A. Figures showing proportion of (Fig. A1) dry and (Fig. A2) moist conifer forest available to treat and hectares actually treated under the active management scenario and different climate assumptions.

Figures showing proportion of (Fig. A1) dry and (Fig. A2) moist conifer forest available to treat and hectares actually treated under the active management scenario and different climate assumptions

Climate Change Adaptation in United States Federal Natural Resource Science and Management Agencies: A Synthesis

This document helps federal agencies recognize the importance of addressing climate change

Understanding and Managing the Effects of Climate Change on Ecosystem Services in the Rocky Mountains

Public lands in the US Rocky Mountains provide critical ecosystem services, especially to rural communities that rely on these lands for fuel, food, water, and recreation. Climate change will likely affect the ability of these lands to provide ecosystem services. We describe 2 efforts to assess climate change vulnerabilities and develop adaptation options on federal lands in the Rocky Mountains. We specifically focus on aspects that affect community economic security and livelihood security, including water quality and quantity, timber, livestock grazing, and recreation. Headwaters of the Rocky Mountains serve as the primary source of water for large populations, and these headwaters are located primarily on public land. Thus, federal agencies will play a key role in helping to protect water quantity and quality by promoting watershed function and water conservation. Although increased temperatures and atmospheric concentration of CO2 have the potential to increase timber and forage production in the Rocky Mountains, those gains may be offset by wildfires, droughts, insect outbreaks, non-native species, and altered species composition. Our assessment identified ways in which federal land managers can help sustain forest and range productivity, primarily by increasing ecosystem resilience and minimizing current stressors, such as invasive species. Climate change will likely increase recreation participation. However, recreation managers will need more flexibility to adjust practices, provide recreation opportunities, and sustain economic benefits to communities. Federal agencies are now transitioning from the planning phase of climate change adaptation to implementation to ensure that ecosystem services will continue to be provided from federal lands in a changing climate