Treesearch

Context: Interactions among disturbances, climate, and vegetation influence landscape patterns and ecosystem processes. Climate changes, exotic invasions, beetle outbreaks, altered fire regimes, and human activities may interact to produce landscapes that appear and function beyond historical analogs. Objectives We used the mechanistic ecosystem-fire process model FireBGCv2 to model interactions of wildland fire, mountain pine beetle (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola) under current and future climates, across three diverse study areas. Methods: We...

Forest management in the face of fire risk is a challenging problem because fire spreads across a landscape and because its occurrence is unpredictable. Accounting for the existence of stochastic events that generate spatial interactions in the context of a dynamic decision process is crucial for determining optimal management. This paper demonstrates a method for incorporating spatial information and interactions into management decisions made over time. A machine learning technique called approximate dynamic programming is applied to determine the optimal timing and location of fuel...

Myotis septentrionalis (Northern Long-eared Bat) is a federally threatened insectivorous bat facing devastating population declines due to white-nose syndrome (WNS). Our study provides pre-WNS (2009) capture rates and roosting-behavior data for Northern Long-eared Bats in the southern Appalachians. We conducted mist-net surveys at 37 sites and radio-tracked female Northern Long-eared Bats to their day roosts in eastern Tennessee and western North Carolina. We compared tree and plot characteristics for roosts and corresponding random trees using Wilcoxon rank-sum tests. Our 43 survey nights...

<>Early successional habitat (ESH) is important for many wildlife species. Over the past century, land use changes have caused ESH to decline in hardwood forests of the eastern United States. Because of the decline of ESH and ESH dependent wildlife, ESH has recently received increased attention from land managers and scientists. Bats, which utilize ESH for foraging, are also a conservation concern, however little information is available on how ESH restoration affects bats. Our objective was to determine how ESH opening size, presence of edge, opening shape, prey abundance, vegetation...

Since the introduction of Dutch elm disease (DED) to North America, heritage elm preservation was paramount, but elm restoration is held as the long-term solution. Various elm restoration efforts have been advanced and encouraged over the past half century, and all have inspired the euphoria of the "Return of the American Elm." The changing cast of characters on the public stage of Main and Elm Streets has, however, been met with mixed reviews.

The use of Dutch elm disease-resistant elms as a common replacement tree in municipal planting schedules has amassed a large population of these trees in many cities throughout the eastern half of the United States. Reports from practitioners have suggested that this population is vulnerable to catastrophic losses due to severe canopy failures during wind-loading events and that American elm (Ulmus americana) selections 'Princeton' and 'Valley Forge' are chronically among the most damaged, which is a combination of poor structure and sheer numbers in the landscape. In this study, tree...

The development of disease-tolerant American elm (Ulmus americana) trees has led to a need for reintroduction and restoration methods for the species. Here we review the current state of experimental work to inform reintroduction biology and restoration ecology of American elm. Much of this work is ongoing, and within several years the results will provide guidance for managers to use the species in restoration plantings. We identify additional research needs and opportunities to consider in development of American elm restoration strategies.

Urban forests contribute significantly to human health and environmental quality (Sanesi et al. 2011). As such, maintaining healthy urban forests resilient to pollution (atmospheric and soil), high temperatures, compacted soils, and poor drainage is critical. However, these forests have been hard hit by development, pests, and pathogens, consequently reshaping their diversity, structure, and resilience.

Because wildfire size and frequency are expected to increase in many forested areas in the United States, organizations involved in forest and wildfire management could arguably benefit from working together and sharing information to develop strategies for how to adapt to this increasing risk. Social capital theory suggests that actors in cohesive networks are positioned to build trust and mutual understanding of problems and act collectively to address these problems, and that actors engaged with diverse partners are positioned to access new information and resources that are important...

Restoration of American elm (Ulmus americana L.) in natural and urban landscapes necessitates the development of new selections that not only exhibit Dutch elm disease (DED, caused by the fungal pathogen Ophiostoma novo-ulmi and O. ulmi) tolerance, but also an increase the genetic variability of tolerant elms. Toward this end, our program tests DED tolerance of large survivor American elms, crosses between DED-tolerant American elms, and crosses between large survivor and DED-tolerant elms. Accurate phenotyping is critical to accurately assess DED-tolerance. This study examined 1) the...