Treesearch

A key assumption of epidemiological models is that population-scale disease spread is driven by close contact between hosts and pathogens. At larger scales, however, mechanisms such as spatial structure in host and pathogen populations and environmental heterogeneity could alter disease spread. The assumption that small-scale transmission mechanisms are sufficient to explain large-scale infection rates, however, is rarely tested. Here, we provide a rigorous test using an insect-baculovirus system. We fit a mathematical model to data from forest-wide epizootics while constraining the model...

Accurate predictions of how weather may affect a wildfire’s behavior are needed to protect crews on the line and efficiently allocate firefighting resources. Since 1988, fire meteorologists have used a tool called the Haines Index to predict days when the weather will exacerbate a wildfire. Although the Haines Index is widely believed to have value, it never received rigorous testing on the line. Even Don Haines, the U.S. Forest Service meteorologist who developed the index, has said the Haines Index needs further refinement.Recognizing that a new fire weather prediction tool was needed, a...

Large wildfires (>50,000 ha) are becoming increasingly common in semiarid landscapes of the western United States. Although fuel reduction treatments are used to mitigate potential wildfire effects, they can be overwhelmed in wind-driven wildfire events with extreme fire behavior. We evaluated drivers of fire severity and fuel treatment effectiveness in the 2014 Carlton Complex, a record-setting complex of wildfires in north-central Washington State. Across varied topography, vegetation, and distinct fire progressions, we used a combination of simultaneous autoregression (SAR) and random...

Streamflow controls many freshwater and marine processes, including salinity profiles, sediment composition, fluxes of nutrients, and the timing of animal migrations. Watersheds that border the Gulf of Alaska (GOA) comprise over 400,000 km2 of largely pristine freshwater habitats and provide ecosystem services such as reliable fisheries for local and global food production. Yet no comprehensive watershed‐scale description of current temporal and spatial patterns of streamflow exists within the coastal GOA. This is an immediate need because the spatial distribution of future streamflow...

Ecologists routinely fit complex models with multiple parameters of interest, where hundreds or more competing models are plausible. To limit the number of fitted models, ecologists often define a model selection strategy composed of a series of stages in which certain features of a model are compared while other features are held constant. Defining these multi-stage strategies requires making a series of decisions, which may potentially impact inferences, but have not been critically evaluated. We begin by identifying key features of strategies, introducing descriptive terms when they did...

Five lichen species were evaluated as element-content pollution bioindicators for a pilot study in Wisconsin and adjacent U.S. states, using data for 20 elements. Goodquality elemental data for aluminum, cobalt, chromium, copper, iron, nitrogen, and sulfur—mostly from nonspecialist U.S. Forest Service Forest Inventory and Analysis staff collections with extensively documented protocols—clearly indicated a site pollution load in the project area. The percentage of nearby land in forest was the strongest predictor for sample collection at study sites of the two most frequent species; such...

An exceptionally powerful storm struck southwestern Washington in December 2007 causing large debris flows in two adjacent streams. The two affected streams had been studied prior to the storm, providing a rare opportunity to examine ecosystem recovery. We monitored the streams and their riparian zones for six years after the disturbances to determine whether recovery rates of biota, physical habitat, and water temperature differed, and if so, what factors affected resilience. Along both streams, the debris flows removed wide swaths of soil, rock, and coniferous riparian forests, widening...

Given the increasing interest in the use of lidar-based remote sensing to support carbon monitoring systems, including those used for measurement, reporting, and verification requirements for REDD+ (reduced emissions from deforestation and degradation) programs in tropical nations, there is a corresponding need for the cost-effective field measurement systems to enable model development and robust assessment of uncertainty in these programs. In this report, we describe an efficient field sampling design and measurement protocol designed to provide field-based estimates of biomass/carbon...

Public lands provide opportunities and settings for people to experience nature and the outdoors. These outdoor experiences are important for human health and well-being and result in visitor spending that benefits local communities. This report shows that new research, tools, and frameworks are needed to help us find new ways to conceptualize outdoor recreation and enhance the ability of public land managers to provide outdoor experiences while protecting natural and cultural resources. The report originated from a set of 17 working papers that were developed as part of an initiative...

Large-scale, high-severity wildfires are a major challenge to the future social-ecological sustainability of fire-adapted forest ecosystems in the American West. Managing forests to mitigate this risk is a collective action problem requiring landowners and stakeholders within multi-ownership landscapes to plan and implement coordinated restoration treatments. Our research question is: how can we promote collective action to reduce wildfire risk and restore fire-resilient forests in the American West? To address this question we draw on collective action theory to produce an environmental...