Helen Sofaer, Ph.D.
Biography
Helen Sofaer is a USGS Mendenhall Research Fellow at the Fort Collins Science Center.
Science and Products
Webinar: Projecting Climate Change Impacts on Wetland-Dependent Birds in the Prairie Pothole Region
View this webinar to learn how scientists are projecting the impacts of climate change on birds in the Prairie Pothole Region.
Documenting, Mapping, and Predicting Invasive Species Using the Fort Collins Science Center's RAM (Resource for Advanced Modeling)
The Resource for Advanced Modeling room provides a collaborative working environment for up to 20 scientists, supported with networked, wireless computing capability for running and testing various scientific models (e.g., Maxent, Boosted Regression Trees, Logistic Regression, MARS, Random Forest) at a variety of spatial scales, from county to global levels. Models use various predictor layers...
Data associated with Sofaer and Jarnevich 'Accounting for sampling patterns reverses the relative importance of trade and climate for the global sharing of exotic plants'
These data were analyzed for the publication 'Accounting for sampling patterns reverses the relative importance of trade and climate for the global sharing of exotic plants'
Data used to estimate and project the effects of climate and land use change on wetland densities in the Prairie Pothole Region
These data were used to estimate models relating climate and land cover to wetland densities and develop projections under climate and land use change.
Non-native plants have greater impacts because of differing per-capita effects and non-linear abundance-impact curves
Invasive, non-native species can have tremendous impacts on biotic communities, where they reduce the abundance and diversity of local species. However, it remains unclear whether impacts of non-native species arise from their high abundance or whether each non-native individual has a disproportionate impact – i.e., a higher per-capita effect – on...
Pearse, Ian; Sofaer, Helen; Zaya, David N.; Spyreas, Greg Clustering and ensembling approaches to support surrogate-based species management
AimSurrogate species can provide an efficient mechanism for biodiversity conservation if they encompass the needs or indicate the status of a broader set of species. When species that are the focus of ongoing management efforts act as effective surrogates for other species, these incidental surrogacy benefits lead to additional efficiency....
Sofaer, Helen; Flather, Curtis H.; Skagen, Susan K.; Steen, Valerie; Noon, Barry R. The area under the precision‐recall curve as a performance metric for rare binary events
Species distribution models are used to study biogeographic patterns and guide decision‐making. The variable quality of these models makes it critical to assess whether a model's outputs are suitable for the intended use, but commonly used evaluation approaches are inappropriate for many ecological contexts. In particular, unrealistically high...
Sofaer, Helen R.; Hoeting, Jennifer A.; Jarnevich, Catherine S. Integrating landscape simulation models with economic and decision tools for invasive species control
In managing invasive species, land managers and policy makers need information to help allocate scarce resources as efficiently and effectively as possible. Decisions regarding treatment methods, locations, effort, and timing can be informed by the integration of landscape simulation models with economic tools. State and transition simulation...
Cullinane Thomas, Catherine; Sofaer, Helen R.; Cline, Sarah A.; Jarnevich, Catherine S. The relationship between invader abundance and impact
The impacts of invasive species generally increase with their abundance, but the form of invader abundance–impact relationships remain poorly described. We highlight the utility of abundance–impact curves for three questions. First, abundance–impact relationships can clarify whether prevention and management should focus on the species likely to...
Sofaer, Helen R.; Jarnevich, Catherine S.; Pearse, Ian S. Misleading prioritizations from modelling range shifts under climate change
AimConservation planning requires the prioritization of a subset of taxa and geographical locations to focus monitoring and management efforts. Integration of the threats and opportunities posed by climate change often relies on predictions from species distribution models, particularly for assessments of vulnerability or invasion risk for...
Sofaer, Helen R.; Jarnevich, Catherine S.; Flather, Curtis H. Projecting species’ vulnerability to climate change: Which uncertainty sources matter most and extrapolate best?
Species distribution models (SDMs) are commonly used to assess potential climate change impacts on biodiversity, but several critical methodological decisions are often made arbitrarily. We compare variability arising from these decisions to the uncertainty in future climate change itself. We also test whether certain choices offer improved skill...
Steen, Valerie; Sofaer, Helen R.; Skagen, Susan K.; Ray, Andrea J.; Noon, Barry R. The relationship between female brooding and male nestling provisioning: does climate underlie geographic variation in sex roles?
Comparative studies of populations occupying different environments can provide insights into the ecological conditions affecting differences in parental strategies, including the relative contributions of males and females. Male and female parental strategies reflect the interplay between ecological conditions, the contributions of the social...
Yoon, Jongmin; Sofaer, Helen R.; Sillett, T. Scott; Morrison, Scott A.; Ghalambor, Cameron K. Accounting for sampling patterns reverses the relative importance of trade and climate for the global sharing of exotic plants
AimThe distributions of exotic species reflect patterns of human-mediated dispersal, species climatic tolerances and a suite of other biotic and abiotic factors. The relative importance of each of these factors will shape how the spread of exotic species is affected by ongoing economic globalization and climate change. However, patterns of trade...
Sofaer, Helen R.; Jarnevich, Catherine S. Designing ecological climate change impact assessments to reflect key climatic drivers
Identifying the climatic drivers of an ecological system is a key step in assessing its vulnerability to climate change. The climatic dimensions to which a species or system is most sensitive – such as means or extremes – can guide methodological decisions for projections of ecological impacts and vulnerabilities. However, scientific workflows for...
Sofaer, Helen R.; Barsugli, Joseph J.; Jarnevich, Catherine S.; Abatzoglou, John T.; Talbert, Marian; Miller, Brian W.; Morisette, Jeffrey T. Projected wetland densities under climate change: Habitat loss but little geographic shift in conservation strategy
Climate change poses major challenges for conservation and management because it alters the area, quality, and spatial distribution of habitat for natural populations. To assess species’ vulnerability to climate change and target ongoing conservation investments, researchers and managers often consider the effects of projected changes in climate...
Sofaer, Helen R.; Skagen, Susan K.; Barsugli, Joseph J.; Rashford, Benjamin S.; Reese, Gordon C.; Hoeting, Jennifer A.; Wood, Andrew W.; Noon, Barry R.