Jeffrey S Evans

Jeffrey S Evans
The Nature Conservancy · Conservation Lands Science Team

35.7
 · 
PhD

About

85
Publications
24,449
Reads
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5,144
Citations
Introduction
I am a senior landscape ecologist for the Nature Conservancy's Conservation Lands Global Science team and affiliate faculty at University of Wyoming. I bring methodology and rigor from diverse fields such as landscape ecology, spatial statistics, applied mathematics and remote sensing to address ecological and conservation questions.
Research Experience
August 2010 - present
University of Wyoming
Position
  • Affiliate professor
Description
  • Teach graduate level courses in "Methods in quantitative ecology" and "spatial statistics".
October 2008 - August 2015
The Nature Conservancy
Position
  • Senior Landscape Ecologist
September 2008 - September 2016
The Nature Conservancy
Position
  • Senior Landscape Ecologist

Publications

Publications (85)
Article
Full-text available
Growing resource demands are driving rapid development to new frontiers in developing countries with important biological diversity. The mitigation hierarchy is a critical tool to manage the impacts of development projects on biodiversity, embedded into numerous government, lender, and corporate policies. However, implementation faces obstacles, in...
Article
A patchwork of disjunct lidar collections is rapidly developing across the USA, often acquired with different acquisition goals and parameters and without field data for forest inventory. Airborne lidar and coincident field data have been used to estimate forest attributes across individual lidar extents, where forest measurements are collected usi...
Article
Full-text available
The expansion of coniferous trees into sagebrush ecosystems is a major driver of habitat loss and fragmentation, resulting in negative impacts to wildlife. Greater sage-grouse (Centrocercus urophasianus) respond directly to conifer expansion through decreased breeding activity, nesting, and overall survival; thus, small amounts of conifer expansion...
Chapter
Throughout the world, countries are planning how to satisfy growing energy demands and, in the shadow of an increasingly changing climate, how to advance alternatives to fossil fuels. The International Energy Agency’s 2040 forecast predicts renewable energy generation reaching 17,970 terawatt hours (51 percent of global electricity demand), with a...
Chapter
This chapter highlights the challenge of meeting conservation goals in the face of a rapidly expanding human population, and advocates for the conservation community to expand its focus from the siting of protected areas to also include spatial planning for how to achieve development objectives. A framework entitled, Development by Design, is intro...
Article
Full-text available
Understanding how bottom-up and top-down forces affect resource selection can inform restoration efforts. With a global population size of <500 individuals, the hirola Beatragus hunteri is the world's most endangered antelope, with a declining population since the 1970s. While the underlying mechanisms are unclear, some combination of habitat loss...
Article
Full-text available
Wetlands are highly dynamic ecosystem components that fluctuate dramatically in inundation and persistence of water both within and across years. However, these systems are commonly classified in a deterministic, discrete manner that does not reflect inherent spatial and temporal variation. Developing a methodology to identify gradients in water in...
Article
Full-text available
We developed rangewide population and habitat models for Greater Sage-Grouse (Centrocercus urophasianus) that account for regional variation in habitat selection and relative densities of birds for use in conservation planning and risk assessments. We developed a probabilistic model of occupied breeding habitat by statistically linking habitat char...
Article
Full-text available
Designing landscapes that can meet human needs, while maintaining functioning ecosystems, is essential for long-term sustainability. To achieve this goal, we must better understand the trade-offs and thresholds in the provision of ecosystem services and economic returns. To this end, we integrate spatially explicit economic and biophysical models t...
Article
Full-text available
Invasive woody plant expansion is a primary threat driving fragmentation and loss of sagebrush (Artemisia spp.) and prairie habitats across the central and western United States. Expansion of native woody plants, including conifer (primarily Juniperus spp.) and mesquite (Prosopis spp.), over the past century is primarily attributable to wildfire su...
Research
Full-text available
USFWS report on spatial-temporal trends of greater sage grouse. • A Bayesian spatial-temporal model (STM) was used to analyze data from sage grouse management zones (MZ) I-V and VII, of the maximum number of males counted per lek per year. • A STM accounts for both spatial and temporal correlations among lek counts. This may be important when the...
Article
Full-text available
Conversion of native habitats to cropland is a leading cause of biodiversity loss. The northeastern extent of the sagebrush (Artemisia L.) ecosystem of western North America has experienced accelerated rates of cropland conversion resulting in many declining shrubland species including greater sage-grouse (Centrocercus urophasianus). Here we presen...
Article
Full-text available
Background: Forest conservation efforts are increasingly being implemented at the scale of sub-national jurisdictions in order to mitigate global climate change and provide other ecosystem services. We see an urgent need for robust estimates of historic forest carbon emissions at this scale, as the basis for credible measures of climate and other...
Data
Complete carbon flux equation. (DOCX)
Data
Legal logging activity methods, and illegal logging emissions methods and results. (DOCX)
Data
Biomass benchmark map methods, results, and comparison with alternatives. (DOCX)
Data
R-code for Monte Carlo simulation. (DOCX)
Data
Methods and results for accuracy assessment of Hansen forest loss product. (DOCX)
Technical Report
Full-text available
We developed range-wide population and habitat models for Greater Sage-grouse (Centrocercus urophasianus) that account for regional variation in habitat selection and relative densities of birds for use in conservation planning and risk assessments. We developed a probabilistic model of occupied breeding habitat by statistically linking habitat cha...
Article
Full-text available
Rapid expansion of cropland threatens grassland ecosystems across western North America and broad-scale planning can be a catalyst motivating individuals and agencies to accelerate conservation. Sprague's Pipit (Anthus spragueii) is an imperiled grassland songbird whose population has been declining rapidly in recent decades. Here, we present a str...
Article
Full-text available
Predicting the locations of future surface coal mining in Appalachia is challenging for a number of reasons. Economic and regulatory factors impact the coal mining industry and forecasts of future coal production do not specifically predict changes in location of future coal production. With the potential environmental impacts from surface coal min...
Article
Full-text available
We used publically available data on duck breeding distribution and recently compiled geospatial data on upland habitat and environmental conditions to develop a spatially explicit model of breeding duck populations across the entire Prairie Pothole Region (PPR). Our spatial population models were able to identify key areas for duck conservation ac...
Chapter
Full-text available
Rare and endangered species attract attention everywhere; this is certainly true within the Western world. During any inventory work at the stations, questions about rare and endangered species come up quickly. It is a very popular topic and many individuals and organizations are interested in trying to save and study these species, or at least to...
Article
Full-text available
This research provides a comprehensive accuracy assessment of five methods for classifying western juniper (Juniperus occidentalis) canopy cover from 1 m, 4-band National Agriculture Imagery Program (NAIP) imagery. Two object-oriented classification approaches (image segmentation and spatial wavelet analysis, (SWA)) are compared to three pixel base...
Article
Full-text available
A common challenge when comparing forest canopy cover and similar metrics across different ecosystems is that there are many field- and landscape-level measurement methods. This research conducts a cross-comparison and evaluation of forest canopy cover metrics produced using unmixing of reflective spectral satellite data, light detection and rangin...
Article
Full-text available
Global demand for energy has increased by more than 50 percent in the last half-century, and a similar increase is projected by 2030. This demand will increasingly be met with alternative and unconventional energy sources. Development of these resources causes disturbances that strongly impact terrestrial and freshwater ecosystems. The Marcellus Sh...
Article
Full-text available
Increasing energy and housing demands are impacting wildlife populations throughout western North America. Greater sage-grouse (Centrocercus urophasianus), a species known for its sensitivity to landscape-scale disturbance, inhabits the same low elevation sage-steppe in which much of this development is occurring. Wyoming has committed to maintain...
Data
Predictor variables included in Random Forests models of change in housing density. An asterisk indicates that the variable was included in the selected best-fitting model. (DOCX)
Data
Projected number of new rural housing structures for each county for short-term and long-term scenarios and incorporated towns from which projected housing structures were excluded. (DOCX)
Data
Additional methods text on oil and gas, wind and residential development modeling. (DOCX)
Article
Improved technologies are needed to advance our knowledge of the biophysical and human factors influencing tropical dry forests, one of the world's most threatened ecosystems. We evaluated the use of light detection and ranging (LiDAR) data to address two major needs in remote sensing of tropical dry forests, i.e., classification of forest types an...
Chapter
The world is on the cusp of a sea change. World population is projected to grow to more than 9 billion by 2050 with rapid development to meet growing demands for food, water, energy, minerals, and other resources. The importance of economic development for improving human well-being means that society will likely value development over conservation...
Article
Full-text available
Repeated perturbations, both biotic and abiotic, can lead to fundamental changes in the nature of ecosystems, including changes in state. Sagebrush steppe communities provide important habitat for wildlife and grazing for livestock. Fire is an integral part of these systems, but there is concern that increased ignition frequencies and invasive spec...
Chapter
Full-text available
Integrating landscape ecology and population genetics (Manel et al. 2003), landscape genetics1 aims to link observed patterns of genetic variation to underlying landscape process(es) (Storfer et al. 2007). Landscape genetics is a useful, emerging approach with the potential to develop new understanding of ecological theory and improve management de...
Chapter
Full-text available
Although inference is a critical component in ecological modeling, the balance between accurate predictions and inference is the ultimate goal in ecological studies (Peters 1991; De’ath 2007). Practical applications of ecology in conservation planning, ecosystem assessment, and bio-diversity are highly dependent on very accurate spatial predictions...
Article
Full-text available
Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production, making appropriate siting and mitigation particularly important. Species that require large unfragmented...
Article
Full-text available
Background: Biodiversity offsets provide a mechanism to compensate for unavoidable damages from new energy development as the U.S. increases its domestic production. Proponents argue that offsets provide a partial solution for funding conservation while opponents contend the practice is flawed because offsets are negotiated without the science nec...
Chapter
Full-text available
Landscape ecology deals fundamentally with how, when, and why patterns of environmental factors influence the distribution of organisms and ecological processes, and reciprocally, how the actions of organisms and ecological processes influence ecological patterns (Urban et al. 1991; Turner 1989). The landscape ecologist's goal is to determine where...
Chapter
Full-text available
Over the past decade the number of statistical modelling tools available to ecologists to model species' distributions has increased at a rapid pace (e.g. Elith et al. 2006; Austin 2007), as have the number of species distribution models (SDM) published in the literature (e.g. Scott et al. 2002). Ten years ago, basic logistic regression (Hosmer and...
Article
Full-text available
You may order additional copies of this publication by sending your mailing information in label form through one of the following media. Please specify the publication title and series number. AbstrAct The fusion of individualistic community ecology with the Hutchinsonian niche concept enabled a broad integration of ecological theory, spanning all...
Chapter
Full-text available
In the preceding chapters we discussed the central role that spatial and temporal variability play in ecological systems, the importance of addressing these explicitly within ecological analyses and the resulting need to carefully consider spatial and temporal scale and scaling. Landscape ecology is the science of linking patterns and processes acr...
Article
Full-text available
A major objective of ecology is to understand how ecological processes limit population connectivity and species' distributions. By spatially quantifying ecological components driving functional connectivity, we can understand why some locally suitable habitats are unoccupied, resulting in observed discontinuities in distribution. However, estimati...
Article
Full-text available
Burn severity classifications derived from multitemporal Landsat Thematic Mapper images and the Normalised Burn Ratio (NBR) are commonly used to assess the post-fire ecological effects of wildfires. Ongoing efforts to retrospectively map historical burn severity require defensible, objective methods of classifying continuous differenced Normalised...
Article
Full-text available
The lack of maps depicting forest three-dimensional structure, particularly as pertaining to snags and understory shrub species distribution, is a major limitation for managing wildlife habitat in forests. Developing new techniques to remotely map snags and understory shrubs is therefore an important need. To address this, we first evaluated the us...
Article
The resolution of current climate interpolation models limits our ability to adequately account for temperature variability in complex mountainous terrain. We empirically derive 30 meter resolution models of June-October day and nighttime temperature and April nighttime Vapor Pressure Deficit (VPD) using hourly data from 53 Hobo dataloggers stratif...
Article
Full-text available
Recent years have seen the progression of light detection and ranging (lidar) from the realm of research to operational use in natural resource management. Numerous government agencies, private industries, and public/private stakeholder consortiums are planning or have recently acquired large-scale acquisitions, and a national U.S. lidar acquisitio...
Article
Full-text available
Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR acr...
Article
We describe and then model satellite-inferred severe (stand-replacing) fire occurrence relative to topography (elevation, aspect, slope, solar radiation, Heat Load Index, wetness and measures of topographic ruggedness) using data from 114 fires > 40 ha in area that occurred between 1984 and 2004 in the Gila Wilderness and surrounding Gila National...
Conference Paper
Background/Question/Methods The lack of maps depicting three-dimensional forest structure, particularly as pertaining to snags and understory shrub distribution, can be a major limitation for managing wildlife habitat in forests. Developing new techniques to map snags and understory shrubs using remote sensing data is therefore an important need....
Article
Full-text available
Quantifying forest structure is important for sustainable forest management, as it relates to a wide variety of ecosystem processes and services. Lidar data have proven particularly useful for measuring or estimating a suite of forest structural attributes such as canopy height, basal area, and LAI. However, the potential of this technology to char...
Article
Full-text available
Landscape ecology often adopts a patch mosaic model of ecological patterns. However, many ecological attributes are inherently continuous and classification of species composition into vegetation communities and discrete patches provides an overly simplistic view of the landscape. If one adopts a niche-based, individualistic concept of biotic commu...
Article
Full-text available
An increased ability to analyze landscapes in a spatial manner through the use of remote sensing leads to improved capabilities for quantifying human-induced forest fragmentation. Developments of spatially explicit methods in landscape analyses are emerging. In this paper, the image delineation software program eCognition and the spatial pattern an...
Article
Full-text available
The percentage tree canopy cover of a forest stand is an important metric widely used in wildland fire behavior simulation models and for habitat assessment. This study assesses the statistical equivalence of canopy cover estimates derived via both spectral and lidar with field measurements. Results show that each remote measure was a good predicto...
Article
Full-text available
Spatial data about the distribution of snags and understory shrubs is a major need for managing wildlife habitat in forests. We are evaluating the use of discrete return LiDAR data for predicting the distribution (presence/absence) of understory shrubs and different classes (i.e. diameters) of snags, in a managed, mixed-conifer forest in Northern I...