Search Results:
View article.
We hypothesized that linear projects were more efficient at intercepting individual fire events over larger spatial domains, whereas radial projects conferred a higher level of network redundancy in terms of the length of the fuel break exposed to fires. We simulated implementation of the alternative project geometries and then examined fuel break-wildfire spatial interactions using a library of simulated fires developed in prior work. The results supported the hypothesis, with linear projects exhibiting substantially greater efficiency in terms of intercepting fires over larger areas, whereas radial projects had a higher interception length given a fire encountered a project. Adding economic objectives made it more difficult to obtain alternative project geometries, but substantially increased net revenue from harvested trees. We discuss how the model and results can be used to further understand decision tradeoffs and optimize the implementation of planned fuel break networks in conjunction with landscape conservation, protection, and restoration management in fire prone regions.
View article.
Widespread, rapid aspen (Populus tremuloides) mortality since the beginning of the 21st century, sometimes called sudden aspen decline (SAD), has been documented in many locations across North America, but it has been particularly pronounced in the southwestern U.S. We investigated the relationship between aspen growth, mortality, and climate across three forest types in northern Arizona using crossdated tree-ring samples from 126 live and 132 dead aspen. Aspen growth was negatively correlated with warm temperatures and positively associated with higher precipitation. Using survival analysis techniques to investigate the links between aspen mortality, tree traits, and climatic conditions, we found that tree traits played a larger role in mortality risk than climate factors. Trees with larger diameters, older trees, and trees with faster growth rates over the past 50 years had a reduced risk of mortality. Management actions aimed at maintaining the most vigorous, fastest growing aspen in the region could help mitigate the impacts of a warmer, drier future.
View paper.
This paper defines the term ecological drought as an episodic deficit in water availability that drives ecosystems beyond thresholds of vulnerability, impacts ecosystem services, and triggers feedbacks in natural and/or human systems. We support this definition with a novel, integrated framework for ecological drought that is organized along two dimensions—the components of vulnerability (exposure + sensitivity/adaptive capacity) and a continuum from human to natural factors. The purpose of this framework is to help guide drought researchers and decision-makers to understand 1) the roles that both people and nature play as drivers of ecosystem vulnerability, 2) that ecological drought’s impacts are transferred to human communities via ecosystem services, and 3) these ecological and ecosystem service impacts will feed back to both natural and human systems. In addition, our framework will help identify important trade-offs and strategies for reducing the ecological drought risks facing both human and natural systems in the 21st century.
The book, Exotic brome-grasses in arid and semiarid ecosystems of the western US: causes, consequences, and management implications, is presented in several chapters.
Access is provided for the following chapters -
Chapter 1 - Introduction: Exotic annual Bromus in the western USA
Chapter 2 - Exotic annual Bromus invasions: comparisons among species and ecoregions in the western US
Chapter 3 - Ecosystem impacts of exotic annual invaders in the genus Bromus
Chapter 7 - Community ecology of fungal pathogens on Bromus tectorum
Chapter 8 - Soil moisture and biogeochemical factors influence the distribution of annual Bromus species
Chapter 9 - Bromus response to climate and projected changes with climate change
Chapter 10 - Plant community resistance to invasion by Bromus species: The roles of community attributes, Bromus interactions with plant communities, and Bromus traits
Chapter 11 - Land uses, fire, and invasion: Exotic annual Bromus and human dimensions
Chapter 12 - Assessing restoration and management needs for ecosystems invaded by exotic annual Bromus species
View guide.
In this study, researchers modeled the climatic envelope for subspecies wyomingensis for contemporary and future climates (decade 2050). Comparison of the contemporary and decade 2050 models shows a predicted 39% loss of suitable climate. Much of this loss will occur in the Great Basin where impacts from increasing fire frequency and encroaching weeds have been eroding the A. tridentata landscape dominance and ecological functions. The goal of this study is to provide a management tool to promote successful restoration by predicting the geographic areas where climate is suitable for this subspecies.
View guide.
This tool is designed to rapidly assess and manage perennial and intermittent lotic (flowing) water systems. Lentic, or still-water, systems, such as wet meadows, swales, seeps and marshes, are inherently different.
This guide is not an instruction manual but a decision-support tool for understanding how riparian areas such as creeks, rivers and streams should function. This guide helps managers determine whether a riparian area is functioning properly and how to restore or maintain proper function. A wide variety of natural resource professionals or land managers will find this guide helpful because it provides a framework for land managers to identify, discuss and address threats to riparian resources.
The goals of this tool are:
- Facilitate communication about riparian conditions across a broad audience of stakeholders.
- Provide an assessment that easily integrates with existing protocols and programs.
- Help users identify factors impacting stream resilience.
- Help users assess and prioritize areas that may require more detailed investigation.
View paper.
Of the approximately 25,000 vascular plant taxa native to the United States, 26% are sold commercially, with growth form, conservation status, distribution, and taxonomy significantly predicting availability. In contrast, only 0.07% of approximately 3,000 native nonvascular taxa are sold commercially. We also investigated how demand for germplasm to support high‐quality restoration efforts is met by vendors in the Midwestern tallgrass prairie region, which has been targeted extensively by restoration efforts for decades. In this well‐developed native plant market, 74% of more than 1,000 target species are commercially available, often from vendors that advertise genetically diverse, locally sourced germplasm. We make recommendations to build on the successes of regional markets like the tallgrass prairie region, and to fill identified gaps, including investing in research to support production, ensuring more consistent and clear demand, and fostering regional collaboration.
View article.
Overall, findings highlight the role of different seasonal ranges on mule deer genetic connectivity, and show that anthropogenic features hinder connectivity. This study demonstrates the value of combining a large, genome-wide marker set with recent advances in landscape genomics to evaluate functional connectivity in a wide-ranging migratory species.
View article.
Researchers developed landscape-directed dispersal simulations and tested a series of replicates that emulate independent empirical datasets for greater sage-grouse and eastern fox snake. The study helps establish methods for using liner mixed models to identify the features underlying patterns of dispersal across a variety of landscapes.