Gregory H. Aplet

Charcoal and carbon storage in forest soils of the Rocky Mountain West

Charcoal represents a super-passive form of carbon (C) that is generated during fire events and is one of the few legacies of fire recorded in the soil profile; however, the importance of this material as a form of C storage has received only limited scientific attention. Here, we review the formation of charcoal in temperate and boreal forest ecosystems, discuss some of its desirable properties, and estimate the potential contribution charcoal to long-term C sequestration in forest ecosystems. Charcoal deposition over the course of several mil lennia probably accounts for a substantial proportion of the total soil C pool in fire-maintained forest ecosystems. Forest management processes that interfere with natural fire processes eliminate the formation of this passive form of C. We recommend that charcoal be considered in C storage budgets and modeling of forest ecosystems, especially in light of climate change and increasing occurrence of wildfire.

Patterns of Community Dynamics in Colorado Engelmann Spruce‐Subalpine Fir Forests

A five-stand chronosequence spanning > 500 yr is used to characterize changes in age structure, overstory mortality, recruitment, and understory growth in developing Colorado Engelmann spruce (Picea engelmannii)-subalpine fir (Abies lasiocarpa) forests. Stand development follows a postdisturbance sequence of colonization, spruce exclusion, spruce reinitiation, and second-generation forest. This model of spruce-fir forest devel- opment reflects a range of disturbance intensities from large conflagrations to small-scale tree deaths. Catastrophic disturbance initiates stand development, and canopy gap replace- ments occur at predictable times during stand development as the life-spans of the two species are expressed. Previously, spruce-fir forests have been described as either equilib- rium or nonequilibrium systems. In the equilibrium coexistence model, spruce and fir constitute a stable, climax community through balanced life history strategies. Nonequi- librium coexistence relies on periodic catastrophic disturbance to disrupt competitive ex- clusion of spruce by fir. Neither of these models, taken alone, adequately explains the range of stand behavior observed in Colorado spruce-fir forests. Instead, stand development appears to involve processes from both models. The stands we investigated are undergoing postfire development and, therefore, support the nonequilibrium model, but a successful spruce cohort late in stand development insures the continued presence of both species, as predicted by the equilibrium model.

Reform forest fire management

Agency incentives undermine policy effectiveness Globally, wildfire size, severity, and frequency have been increasing, as have related fatalities and taxpayer-funded firefighting costs (1). In most accessible forests, wildfire response prioritizes suppression because fires are easier and cheaper to contain when small (2). In the United States, for example, 98% of wildfires are suppressed before reaching 120 ha in size (3). But the 2% of wildfires that escape containment often burn under extreme weather conditions in fuel-loaded forests and account for 97% of fire-fighting costs and total area burned (3). Changing climate and decades of fuel accumulation make efforts to suppress every fire dangerous, expensive, and ill advised (4). These trends are attracting congressional scrutiny for a new approach to wildfire management (5). The recent release of the National Cohesive Wildland Fire Management Strategy (NCWFMS) (6) and the U.S. Forest Services (USFSs) current effort to revise national forest (NF) plans provide openings to incentivize change. Although we largely focus on the USFS, which incurs 70% of national firefighting costs (7), similar wildfire policies and needed management reforms are relevant throughout the United States and fire-prone areas worldwide.

Guiding concepts for park and wilderness stewardship in an era of global environmental change.

The major challenge to stewardship of protected areas is to decide where, when, and how to intervene in physical and biological processes, to conserve what we value in these places. To make such decisions, planners and managers must articulate more clearly the purposes of parks, what is valued, and what needs to be sustained. A key aim for conservation today is the maintenance and restoration of biodiversity, but a broader range of values are also likely to be considered important, including ecological integrity, resilience, historical fidelity (ie the ecosystem appears and functions much as it did in the past), and autonomy of nature. Until recently, the concept of “naturalness” was the guiding principle when making conservation-related decisions in park and wilderness ecosystems. However, this concept is multifaceted and often means different things to different people, including notions of historical fidelity and autonomy from human influence. Achieving the goal of nature conservation intended for such...

Restoring fire-prone Inland Pacific landscapes: seven core principles

ContextMore than a century of forest and fire management of Inland Pacific landscapes has transformed their successional and disturbance dynamics. Regional connectivity of many terrestrial and aquatic habitats is fragmented, flows of some ecological and physical processes have been altered in space and time, and the frequency, size and intensity of many disturbances that configure these habitats have been altered. Current efforts to address these impacts yield a small footprint in comparison to wildfires and insect outbreaks. Moreover, many current projects emphasize thinning and fuels reduction within individual forest stands, while overlooking large-scale habitat connectivity and disturbance flow issues.MethodsWe provide a framework for landscape restoration, offering seven principles. We discuss their implication for management, and illustrate their application with examples.ResultsHistorical forests were spatially heterogeneous at multiple scales. Heterogeneity was the result of variability and interactions among native ecological patterns and processes, including successional and disturbance processes regulated by climatic and topographic drivers. Native flora and fauna were adapted to these conditions, which conferred a measure of resilience to variability in climate and recurrent contagious disturbances.ConclusionsTo restore key characteristics of this resilience to current landscapes, planning and management are needed at ecoregion, local landscape, successional patch, and tree neighborhood scales. Restoration that works effectively across ownerships and allocations will require active thinking about landscapes as socio-ecological systems that provide services to people within the finite capacities of ecosystems. We focus attention on landscape-level prescriptions as foundational to restoration planning and execution.

Identifying Corridors among Large Protected Areas in the United States

Conservation scientists emphasize the importance of maintaining a connected network of protected areas to prevent ecosystems and populations from becoming isolated, reduce the risk of extinction, and ultimately sustain biodiversity. Keeping protected areas connected in a network is increasingly recognized as a conservation priority in the current era of rapid climate change. Models that identify suitable linkages between core areas have been used to prioritize potentially important corridors for maintaining functional connectivity. Here, we identify the most “natural” (i.e., least human-modified) corridors between large protected areas in the contiguous Unites States. We aggregated results from multiple connectivity models to develop a composite map of corridors reflecting agreement of models run under different assumptions about how human modification of land may influence connectivity. To identify which land units are most important for sustaining structural connectivity, we used the composite map of corridors to evaluate connectivity priorities in two ways: (1) among land units outside of our pool of large core protected areas and (2) among units administratively protected as Inventoried Roadless (IRAs) or Wilderness Study Areas (WSAs). Corridor values varied substantially among classes of “unprotected” non-core land units, and land units of high connectivity value and priority represent diverse ownerships and existing levels of protections. We provide a ranking of IRAs and WSAs that should be prioritized for additional protection to maintain minimal human modification. Our results provide a coarse-scale assessment of connectivity priorities for maintaining a connected network of protected areas.

Wild, connected, and diverse: building a more resilient system of protected areas

Current systems of conservation reserves may be insufficient to sustain biodiversity in the face of climate change and habitat losses. Consequently, calls have been made to protect Earths remaining wildlands and complete the system of protected areas by establishing conservation reserves that (1) better represent ecosystems, (2) increase connectivity to facilitate biota movement in response to stressors including climate change, and (3) promote species persistence within intact landscapes. Using geospatial data, we conducted an assessment for expanding protected areas within the contiguous United States to include the least human-modified wildlands, establish a connected network, and better represent ecosystem diversity and hotspots of biodiversity. Our composite map highlights areas of high value to achieve these goals in the western United States, where existing protected areas and lands with high ecological integrity are concentrated. We also identified important areas in the East rich in species and containing ecosystems that are poorly represented in the existing protected area system. Expanding protection to these priority areas is ultimately expected to create a more resilient system for protecting the nations biological heritage. This expectation should be subject to rigorous testing prior to implementation, and regional monitoring will ensure areas and actions are adjusted over time.

Reform forest fire management: Agency incentives undermine policy effectiveness

Agency incentives undermine policy effectiveness Globally, wildfire size, severity, and frequency have been increasing, as have related fatalities and taxpayer-funded firefighting costs (1). In most accessible forests, wildfire response prioritizes suppression because fires are easier and cheaper to contain when small (2). In the United States, for example, 98% of wildfires are suppressed before reaching 120 ha in size (3). But the 2% of wildfires that escape containment often burn under extreme weather conditions in fuel-loaded forests and account for 97% of fire-fighting costs and total area burned (3). Changing climate and decades of fuel accumulation make efforts to suppress every fire dangerous, expensive, and ill advised (4). These trends are attracting congressional scrutiny for a new approach to wildfire management (5). The recent release of the National Cohesive Wildland Fire Management Strategy (NCWFMS) (6) and the U.S. Forest Services (USFSs) current effort to revise national forest (NF) plans provide openings to incentivize change. Although we largely focus on the USFS, which incurs 70% of national firefighting costs (7), similar wildfire policies and needed management reforms are relevant throughout the United States and fire-prone areas worldwide.

A portfolio approach to managing ecological risks of global change

Abstract The stressors of global environmental change make it impossible over the long term for natural systems to maintain their historical composition. Conservations new objective must be to maintain the building blocks of future systems (e.g., species, genes, soil types, and landforms) as they continuously rearrange. Because of the certainty of change, some biologists and managers question continued use of retrospective conservation strategies (e.g., reserves and restoration) informed by the historical range of variability. Prospective strategies that manage toward anticipated conditions have joined the conservation toolbox alongside retrospective conservation. We argue that high uncertainty around the rates and trajectories of climate and ecological change dictate the need to spread ecological risk using prospective and retrospective strategies across conservation networks in a systematic and adaptively managed approach. We term this a portfolio approach drawing comparisons to financial portfolio risk management as a means to maximize conservation benefit and learning. As with a financial portfolio, the portfolio approach requires that management allocations receive minimum temporal commitments to realize longer‐term benefits. Our approach requires segregation of the strategies into three landscape zones to avoid counterproductive interactions. The zones will be managed to (1) observe change, (2) resist change, and (3) facilitate change. We offer guidelines for zone allocation based on ecological integrity. All zones should follow principles of conservation design traditionally applied to reserves. Comparable to financial portfolios, zone performance is monitored to facilitate learning and potential reallocation for long‐term net minimization of risk to the building blocks of future ecosystems.

Land protection and timber harvesting along productivity and diversity gradients in the Northern Rocky Mountains

Understanding the complex and reciprocal ways in which ecosystem functions (such as productivity) and biodiversity interact may provide important insights into sustaining ecosystem services and protecting species diversity. Despite years of research, observed relationships between productivity and biodiversity have been varied and hypotheses explaining patterns are diverse and equivocal. The ways in which patterns of productivity-biodiversity relationships can inform conservation may depend on understanding how gradients in human land use map onto gradients of productivity and biodiversity. Here, we used diverse publicly available spatial datasets on ecosystem productivity, tree diversity, climate, and land cover to explore two broad questions in ecoregions of Montana: (1) what is the relationship between productivity and tree diversity and (2) are land use gradients (from timber harvesting to wilderness protection) related to gradients of productivity and diversity? We also investigated the possible climatic and topographic drivers of these ecological and anthropogenic patterns. We found the most productive ecoregions support greater numbers of tree species, which appears to be influenced by precipitation but not temperature gradients. The most productive and diverse ecoregions included greater amounts of timber harvesting disturbance and associated road densities. The amount of protected area within ecoregions was highest at intermediate levels of productivity and diversity and was strongly related to mean elevation of ecoregions. Our results suggest that climate-influenced productivity gradients may influence patterns of biodiversity and are related to patterns in human land use. Further, given the existing conditions and current distribution of protected areas, we recommend that the most altered productive and diverse ecoregions may offer opportunities both for additional protection and for holistic restoration programs.