Helen Sofaer, Ph.D.
Biography
Helen Sofaer is a Research Ecologist at the Pacific Island Ecosystems Research Center in Hawaii.
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.
Negative effects of an allelopathic invader on AM fungal plant species drive community‐level responses
The mechanisms causing invasive species impact are rarely empirically tested, limiting our ability to understand and predict subsequent changes in invaded plant communities. Invader disruption of native mutualistic interactions is a mechanism expected to have negative effects on native plant species. Specifically, disruption of native plant‐fungal...
Roche, Morgan; Pearse, Ian; Bialic-Murphy, Lalasia; Kivlin, Stephanie N; Sofaer, Helen; Kalisz, Susan
Ecological forecasting—21st century science for 21st century management
Natural resource managers are coping with rapid changes in both environmental conditions and ecosystems. Enabled by recent advances in data collection and assimilation, short-term ecological forecasting may be a powerful tool to help resource managers anticipate impending near-term changes in ecosystem conditions or dynamics. Managers may use the...
Bradford, John B.; Weltzin, Jake; Mccormick, Molly; Baron, Jill; Bowen, Zack; Bristol, Sky; Carlisle, Daren; Crimmins, Theresa; Cross, Paul; DeVivo, Joe; Dietze, Mike; Freeman, Mary; Goldberg, Jason; Hooten, Mevin; Hsu, Leslie; Jenni, Karen; Keisman, Jennifer L.; Kennen, Jonathan; Lee, Kathy; Lesmes, David; Loftin, Keith; Miller, Brian W.; Murdoch, Peter S.; Newman, Jana; Prentice, Karen L.; Rangwala, Imtiaz; Read, Jordan; Sieracki, Jennifer; Sofaer, Helen; Thur, Steve; Toevs, Gordon; Werner, Francisco; White, C. LeAnn; White, Timothy; Wiltermuth, Mark A modeling workflow that balances automation and human intervention to inform invasive plant management decisions at multiple spatial scales
Predictions of habitat suitability for invasive plant species can guide risk assessments at regional and national scales and inform early detection and rapid-response strategies at local scales. We present a general approach to invasive species modeling and mapping that meets objectives at multiple scales. Our methodology is designed to balance...
Young, Nicholas E.; Jarnevich, Catherine S.; Sofaer, Helen; Pearse, Ian; Sullivan, Julia; Engelstad, Peder; Stohlgren, Thomas J. Co-occurrence and occupancy dynamics of mourning doves and Eurasian collared-doves
Understanding how land cover and potential competition with invasive species shape patterns of occupancy, extirpation, and colonization of native species across a landscape can help target management for declining native populations. Mourning dove (Zenaida macroura) populations have declined throughout the United States from 1965–2015. The...
Green, Adam W.; Sofaer, Helen; Otis, David L; Van Lanen, Nicholas J The development and delivery of species distribution models to inform decision-making
Information on where species occur is central to conservation and management decisions, but knowledge of distributions can be coarse or incomplete. Species distribution models provide a tool for mapping suitable habitat, and can produce credible, defensible, and repeatable predictive information with which to inform decisions. However, these...
Sofaer, Helen; Jarnevich, Catherine S.; Pearse, Ian; Smyth, Regan L; Auer, Stephanie; Cook Gericke L; Edwards, Thomas C.; Guala, Gerald F.; Howard, Timothy G; Morisette, Jeffrey T; Hamilton, Healy 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; 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; 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; 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; 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; Skagen, Susan K.; Ray, Andrea J.; Noon, Barry R.