Treesearch

An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR)...

The burning rate of unconfined cribs has long been identified to occur in two regimes: the densely-packed regime where the burning rate is proportional to the crib porosity and the loosely-packed regime where the burning rate is independent of porosity. Though the cribs used to define these burning regimes were primarily cubic in dimension, there are seemingly endless possible ways to build a crib with a given porosity. This work explores the burning rate of cribs with a wide variety of geometries to determine whether the porosity-burning rate relation in the literature holds. One set of...

Policy makers face complex situations involving the analysis and weighting of multiple incentives that complicate the design of natural resource and environmental policy. The objective of this dissertation is to characterize policy makers’ incentives, and to investigate the consequences of those incentives on environmental and economic outcomes in the context of wildfire management and environmental policy.

Recent surveys of belowground fungal biodiversity in Mexico and USA have revealed many undescribed truffle species, including many in the genus Tuber. Here we describe seven new species: Tuber beyerlei, T. castilloi, T. guevarai, T. lauryi, T. mexiusanum, T. miquihuanense and T. walkeri. Phylogenetic analyses place these species within the Maculatum group, an understudied clade of small truffles with little apparent economic value. These species are among the more taxonomically challenging in the genus. We collected Tuber castilloi, T. mexiusanum and T. guevarai as fruit bodies and...

Fungal mitospores may function as dispersal units and/ or spermatia and thus play a role in distribution and/or mating of species that produce them. Mitospore production in ectomycorrhizal (EcM) Pezizales is rarely reported, but here we document mitospore production by a high diversity of EcM Pezizales on three continents, in both hemispheres. We sequenced the internal transcribed spacer (ITS) and partial large subunit (LSU) nuclear rDNA from 292 spore mats (visible mitospore clumps) collected in Argentina, Chile, China, Mexico and the USA between 2009 and 2012. We collated spore mat ITS...

We examine challenges and opportunities involved in applying ecosystem services to public land management with an emphasis on national forests in the United States. We review historical forest management paradigms and related economic approaches, outline a conceptual framework defining the informational needs of forest managers, and consider the feasibility of its application given the types of ecological information typically available and the expanding set of services considered in management decisions. Economists can make their work more relevant to managers by broadening their focus to...

The Wildland Fire Decision Support System (WFDSS) web-based application leverages geospatial data to inform strategic decisions on wildland fires. A specialized data team, working within the Wildland Fire Management Research Development and Application group (WFM RD&A), assembles authoritative national-level data sets defining values to be protected. The use of such high-quality trusted data ensures that critical resources, infrastructure and firefighter risk exposure are considered in both the planning and implementation phases of incident management (Figure 3 and Table 1).

The loss of homes to wildfires is an important issue in the USA and other countries. Yet many homeowners living in fire-prone areas do not undertake mitigating actions, such as clearing vegetation, to decrease the risk of losing their home. To better understand the complexity of wildfire risk-mitigation decisions and the role of perceived risk, we conducted a survey of homeowners in a fire-prone area of the front range of the Rocky Mountains in Colorado. We examine the relationship between perceived wildfire risk ratings and risk-mitigating behaviours in two ways. First, we model wildfire...

Forests need a lot of water to produce the goods (e.g., timber) and services (e.g., carbon sequestration and climate moderation) that benefit humans. Forests grow naturally in water-rich regions where precipitation is abundant or where groundwater is available, such as riparian areas in arid regions. For example, loblolly pine (Pinus taeda L.) forests are found in areas where mean annual precipitation normally exceeds 1,000 mm/yr (40 inches/yr). However, under climate change scenarios, water availability is projected to decrease and become more variable in the future, potentially impacting...

Understanding the habitat relationships of rare species is critical to conserving populations and habitats of those species. Nesting habitat is suspected to limit distribution of the threatened Mexican spotted owl (Strix occidentalis lucida), and may vary among geographic regions. We studied selection of nesting habitat by Mexican spotted owls within their home ranges in the Sacramento Mountains, New Mexico. We compared characteristics of owl nest trees and nest sites to characteristics of randomly located trees and sites at 2 spatial scales: the general nest vicinity and within activity...