Treesearch

Over the past several decades, the management of historically frequent-fire forests in the western United States has received significant attention due to the linked ecological and social risks posed by the increased occurrence of large, contiguous patches of high-severity fire. As a result, efforts are underway to simultaneously reduce potential fire and fuel hazards and restore characteristics indicative of historical forest structures and ecological processes that enhance the diversity and quality of wildlife habitat across landscapes. Despite widespread agreement on the need for...

Adverse effects of wildfires can be mitigated within fuel treatments, but empirical evidence of their effectiveness across large areas is needed to guide design and implementation at the landscape level. We conducted a systematic literature review of empirically based studies that tested the influence of landscape-level fuel treatments on subsequent wildfires in North America over the past 30 years to evaluate how treatment type and configuration affect subsequent wildfire behavior or enable more effective wildfire response.

Accurately predicting pedestrian travel times is critically valuable in emergency response, wildland firefighting, disaster management, law enforcement, and urban planning. However, the relationship between pedestrian movement and landscape conditions is highly variable between individuals, making it difficult to estimate how long it will take broad populations to get from one location to another on foot. Although functions exist for predicting travel rates, they typically oversimplify the inherent variability of pedestrian travel by assuming the effects of landscapes on movement are...

Whitebark pine (Pinus albicaulis Engelm.) is an ecologically important subalpine and treeline forest tree of the western U.S. and Canada. It is categorized as endangered by the IUCN and by Canada under the Species at Risk Act and was recently proposed for listing in the U.S. as threatened under the Endangered Species Act. Whitebark pine populations are declining nearly rangewide primarily from the spread and intensification of Cronartium ribicola J.C. Fisch., the exotic, invasive pathogen that causes white pine blister rust (WPBR); recent, large-scale outbreaks of mountain pine beetles...

Westslope Cutthroat Trout Oncorhynchus clarkii lewisi (WCT), the dominant nonanadromous salmonid in central and northern Idaho, historically were extremely abundant and widely distributed. Despite restricted harvest methods and limits since 1899, many WCT populations declined and by the 1960s, populations in several major drainages were on the brink of collapse. In response, fisheries biologists began investigating WCT population dynamics, life histories, and habitat requirements and developed evidence-based regulations and habitat restoration alternatives. Here we describe fluvial WCT...

Restoring wide areas of fire excluded western US landscapes to fuel limited, fire resilient systems where fires self-regulate and burn with low or mixed severity will require expanded use of both prescribed and natural fire, coupled with strategic mechanical fuels management. However, optimal admixtures of fire and fuel management to set landscapes on trajectories to improve fire resilience and conserve carbon are not well understood.

The National Predictive Services (NPS) asked the USFS Rocky Mountain Center for Fire-Weather Intelligence (RMC) as a part of the Fire, Fuel, and Smoke Science Program (FFS) at the USFS Rocky Mountain Research Station (RMRS) to assist with the development of a system of statistical models for predicting the ignition probability (chance of start) & growth potential of wildfires on a national grid using NWS meteorological forecast data as input. The development of this gridded system of predictive equations was envisioned to proceed in 3 stages (phases).

Reintroducing native carnivores risks creating conflict with people and consequently reducing support for coexistence and conservation efforts. Determining the interface between areas of ecological suitability and conflict risk can help enhance success of carnivore restoration, but this is often difficult because accurate data on risks and tolerance are lacking. Gray wolves (Canis lupus), a focus of reintroduction efforts in the US, require tolerance to persist in human-dominated landscapes but also catalyze societal-level conflicts throughout their global range. Via an unprecedented...

Plants resist herbivores and pathogens by using constitutive (baseline) and inducible (change in defense after an attack) defenses. Inducibility has long been predicted to trade off with constitutive defense, reflecting the economic use of resources. However, empirical evidence for such tradeoffs is variable, and we still lack understanding about when and where defense trade-offs occur. We tested for tradeoffs between constitutive and induced defenses in natural populations of three species of long-lived pines (Pinus balfouriana, P. flexilis, P. longaeva) that differ greatly in constitutive...

Trade-offs between plant defense investment and fitness traits, including growth, are often invoked to explain evolutionary strategies targeted at resisting herbivores. Many Pinus species have specialized herbivores, including the mountain pine beetle (MPB), Dendroctonus ponderosae, and have historically been a focus of defense investigations. We compared defense traits of two high-elevation Pinus species, P. aristata and P. flexilis, that are hosts to MPB and hypothesized to have different growth and defense traits and potential trade-offs. Interspecific differences were assessed by...