Treesearch

Burn severity maps based on remotely sensed reflectance data provide a useful way for land managers and researchers to represent and compare spatial variation in fire effects among wildfires and prescribed fires. A need exists for an objective and rigorous selection approach that ensures the best possible spatial predictions of burn severity. The aim of this study was to present and test a methodology for selecting the optimal burn severity index from a suite of calculation and validation options that can be used to produce data for more rigorously comparing ecological effects of fire that...

1. Significant research has been devoted to the development of semiochemical repellents for mountain pine beetle Dendroctonus ponderosaeHopkins. Several formulations of the beetle's antiaggregation pheromone verbenone (4,6,6‐trimethylbicyclo[3.1.1]hept‐3‐en‐2‐one) are registered to protect pine trees and stands. 2. We compared the efficacy of verbenone and Verbenone Plus for protecting individual lodgepole pine Pinus contortaDougl. ex Loud. and small stands of P. contortafrom mortality attributed to D. ponderosae. Verbenone Plus is a blend of semiochemicals [(−)‐verbenone, acetophenone,...

The seventh sudden oak death science and management symposium provided a forum for current research concerning sudden oak death caused by the exotic, quarantine pathogen, Phytophthora ramorum. Nearly 50 submissions describing papers or posters on the following sudden oak death/P. ramorum topics are included: ecology, monitoring, and nursery and wildland management. Abstracts are also provided from sessions on Phytophthoras in California native plant nurseries and restoration sites.

The effects of leaf litter on moisture content and fungal decay development in above-ground wood specimens were assessed. Untreated southern pine specimens were exposed with or without leaf litter contact. Two types of leaf litter were evaluated; aged (decomposed) and young (early stages of decomposition). The moisture content of specimens was monitored, and specimens were periodically removed for visual evaluation of decay development. In addition, amplicon-based sequencing analysis of specimens and associated leaf litter was conducted at two time points. Contact with either type of leaf...

Fuels reduction treatments to mitigate fire behavior are common in ponderosa pine ecosystems of the western United States. While initial impacts of fuel treatments have been reported, less is known about treatment longevity as live and dead fuels change with time. We analyzed fuel dynamics in ponderosa pine-Douglas-fir forests 21-23 years following experimental fuel reduction designed as two independent studies of cutting combined with burning: one tested a commercial thinning strategy, while a second tested a retention shelterwood strategy to reduce fuels while also restoring ponderosa...

Fire refugia-locations that burn less severely or less frequently than surrounding areas - support late-successional and old-growth forest structure and function. This study investigates the influence of topography and fuels on the probability of forest fire refugia under varying fire weather conditions. We focused on recent large fires in Oregon and Washington, United States (n = 39 fires > 400 ha, 2004-2014). Our objectives were to (1) map fire refugia as a component of the burn severity gradient, (2) quantify the predictability of fire refugia as a function of prefire fuels and topograph...

Fire-sustained open oak and pine forests were once widespread across eastern North America, but are now comparatively scarce. To regain the goods and services of these open forests, managers are increasingly looking to restore them with the silvicultural systems and tools best suited to meet their objectives. Hence, we syn-thesized a number of research efforts and case studies from open pine, mixedwood, and oak-dominated forests in eastern North America to demonstrate the silvicultural options available and recognized knowledge gaps. The silvicultural treatment options and tools available...

Throughout much of American chestnut's range, the tree co-occurs with various species of oak, commonly northern red and chestnut oak. Oaks benefited from the loss of chestnut, by taking advantage of the increased light and growing space made available when its once abundant cousin was largely extirpated (Wang and Hu 2015). More recent changes in oak-dominated forests, such as increased herbivory and alteration to disturbance regimes, however, threaten the continued dominance of these species (Dey 2014). Because of this, promotion of oak regeneration is now a predominant focus of silvicultur...

The effects of enhanced acid deposition fromthe atmosphere, and associated elevated inputs of N, are widely evident, especially for forests where excess N has led to a variety of deleterious effects. These include declines in biodiversity, a response that will likely require considerable time for recovery. The purpose of this study was to determine responses of plant nutrient availability in surface mineral soil to 25 yr of experimental acidification and N addition in a central Appalachian hardwood forest ecosystem. We hypothesized that chronic additions of (NH4)2SO4 will increase mineral...

Thermal regimes of rivers and streams profoundly affect aquatic ecosystems, but are poorly described and classified in many areas due to the limited availability of annual datasets from extensive and representative monitoring networks. By mining a new temperature database composed of >23,000 site records that spans the western United States (U.S.), we extract annual monitoring records at 578 sites on perennial streams to describe regimes in this diverse region. Records were summarized using 34 metrics that described regime aspects related to magnitude, variation, frequency, duration, and...