Skip to main content
U.S. flag

An official website of the United States government

Ian Pearse, PhD

Ian is an ecologist who works on plants and insects.

Ian conducts research at the individual, population, community, and ecosystem level scales. His work focuses on plant-insect interactions and involves work on endangered insects such as bumble bees, strategies to map and control invasive plants, the chemical ecology and behaviors that affect herbivory, and the boom and bust seed production dynamics of many trees (i.e. mast seeding). His work informs management decisions made by the US Fish and Wildlife Service, National Parks, and a variety of other groups. Ian is especially fond of oak trees and spends a considerable amount of time staring up into them with the vague excuse of counting acorns, gall wasps, or rates of herbivory.

Professional Experience

  • 2016 Postdoctoral work, University of California, Davis

  • 2014-2015 Postdoctoral work, Illinois Natural History Survey

  • 2012-2013 Postdoctoral work, Cornell University

Education and Certifications

  • PhD Entomology, University of California, Davis, 2011

  • BS Plant Biology, University of Illinois, Urbana-Champaign 2004

Affiliations and Memberships*

  • International Oak Society

  • Ecological Society of America

  • Entomological Society of America

Science and Products

USGS

Scaling-up phenological date matching for invasive species mapping: a free opensource workflow

Matching imagery dates to phenological events across large geographic regions for invasive species mapping.
By
Community for Data Integration (CDI)
Scaling-up phenological date matching for invasive species mapping: a free opensource workflow

Scaling-up phenological date matching for invasive species mapping: a free opensource workflow

Matching imagery dates to phenological events across large geographic regions for invasive species mapping.
Learn More
a website with sidebar on the left and buttons, a map of the united states, and a color key

INHABIT: A web tool for invasive plant management across the contiguous United States

INHABIT is a desktop-optimized web application and decision support tool with mapped and tabular summaries of habitat suitability models for over two hundred fifty terrestrial invasive plant species of management concern across the contiguous United States. It is the product of a scientist-practitioner partnership and is designed to facilitate enhanced invasive species management actions...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
INHABIT: A web tool for invasive plant management across the contiguous United States

INHABIT: A web tool for invasive plant management across the contiguous United States

INHABIT is a desktop-optimized web application and decision support tool with mapped and tabular summaries of habitat suitability models for over two hundred fifty terrestrial invasive plant species of management concern across the contiguous United States. It is the product of a scientist-practitioner partnership and is designed to facilitate enhanced invasive species management actions...
Learn More
photo of dry grasses

Predicting risk of annual grass invasion following fire in sagebrush steppe and rangeland ecosystems

This project analyzes on-the-ground plant monitoring data across sagebrush and rangeland ecosystems to examine how fire, climate, topography, and plant communities influence the success of invasive annual grasses after fires.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Land Management Research Program, Fort Collins Science Center, Wildland Fire Science
Predicting risk of annual grass invasion following fire in sagebrush steppe and rangeland ecosystems

Predicting risk of annual grass invasion following fire in sagebrush steppe and rangeland ecosystems

This project analyzes on-the-ground plant monitoring data across sagebrush and rangeland ecosystems to examine how fire, climate, topography, and plant communities influence the success of invasive annual grasses after fires.
Learn More
close-up of cheatgrass stalk in a field of cheatgrass

Predicting the phenology of invasive grasses under a changing climate to inform mapping and management

Cheatgrass, an invasive annual grass, reduces ecosystem productivity, negatively impacts biodiversity, and is increasingly problematic in higher elevation ecosystems with climate change. Cheatgrass phenology (that is, the timing of yearly growth and lifespan) varies greatly with elevation, climate, and weather from year to year, which can make management planning difficult and reduce the ability...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
Predicting the phenology of invasive grasses under a changing climate to inform mapping and management

Predicting the phenology of invasive grasses under a changing climate to inform mapping and management

Cheatgrass, an invasive annual grass, reduces ecosystem productivity, negatively impacts biodiversity, and is increasingly problematic in higher elevation ecosystems with climate change. Cheatgrass phenology (that is, the timing of yearly growth and lifespan) varies greatly with elevation, climate, and weather from year to year, which can make management planning difficult and reduce the ability...
Learn More
Image Collage of Landsat, pollinator, and volcanologist

Developing a macroecological understanding of invasive plant impacts based on abundance and trait data

Understanding invasive plant impacts can provide insight into community assembly and inform the development of successful management strategies. The impacts of invasive species depend on how they alter patterns of abundance within recipient communities and on the characteristics of the invaders and the affected species. Research has suggested that common species may be more impacted by...
By
John Wesley Powell Center for Analysis and Synthesis
Developing a macroecological understanding of invasive plant impacts based on abundance and trait data

Developing a macroecological understanding of invasive plant impacts based on abundance and trait data

Understanding invasive plant impacts can provide insight into community assembly and inform the development of successful management strategies. The impacts of invasive species depend on how they alter patterns of abundance within recipient communities and on the characteristics of the invaders and the affected species. Research has suggested that common species may be more impacted by invasions,
Learn More
Filter Total Items: 28

Data to fit habitat suitability models at different invasion stages and their results to evaluate model decisions Data to fit habitat suitability models at different invasion stages and their results to evaluate model decisions

This is a dataset containing the input and output data used in the analysis of best practices of invasive plant species distribution modeling (Young et al. 2024). We developed habitat suitability models for 13 invasive plant species at a variety of geographic ranges and different invasion stages and modeling strategies to assess the impact of predictor quality, thinning resolution, and...
By
Fort Collins Science Center

Community level traits of invaded plant communities in the United States Community level traits of invaded plant communities in the United States

Data were compiled from large trait databases for functional above and belowground traits (e.g. specific leaf area, specific root length, etc) of plants in communities across the United States along with information about the degree to which invasive species dominate those communities.
By
Fort Collins Science Center

INHABIT species potential distribution across the contiguous United States (ver. 4.0, June 2024) INHABIT species potential distribution across the contiguous United States (ver. 4.0, June 2024)

This is a dataset containing the potential distribution of 259 invasive terrestrial plant species. We developed habitat suitability models for invasive plant species selected by Department of Interior land management agencies and other managers. We applied the modeling workflow developed in Young et al. (2020, https://doi.org/10.1371/journal.pone.0229253) and adapted by Jarnevich et al....
By
Fort Collins Science Center

Projections of post-fire cover of non-native short-lived grasses and forbs under current and future climate conditions Projections of post-fire cover of non-native short-lived grasses and forbs under current and future climate conditions

These data provide current and future projected post-fire invasion risk by non-native short-lived grasses and forbs based on vegetation cover data from 26,729 plots in the western United States that burned prior to being sampled. Projected post-fire invasion risk was calculated using random forests with gridded climate, soil, and topographic predictor variables following Prevéy et al....
By
Fort Collins Science Center

Population genetic analysis of the rusty patched bumble bee in extant locations in 2022 Population genetic analysis of the rusty patched bumble bee in extant locations in 2022

This is a dataset of locations and population genetic information based on microsatellite analysis of rusty patched bumble bee (Bombus affinis). Data were collected over the course of two years (2020 and 2021), and genetic analysis took place in 2022.
By
Fort Collins Science Center

Potential distribution of Japanese brome (Bromus japonicus) across the contiguous United States (October 2023) Potential distribution of Japanese brome (Bromus japonicus) across the contiguous United States (October 2023)

This is a dataset containing the potential distribution of Japanese brome (Bromus japonicus). We developed habitat suitability models for Japanese brome, as suggested by Department of Interior land management agencies. We applied the modeling workflow developed in Young et al. 2020 to species not included in the original case studies. Our methodology balanced trade-offs between...
By
Fort Collins Science Center

Management summary table for INHABIT species potential distribution across the contiguous United States: additional management units Management summary table for INHABIT species potential distribution across the contiguous United States: additional management units

We developed habitat suitability models for invasive plant species selected by Department of Interior land management agencies. We applied the modeling workflow developed in Young et al. 2020 to species not included in the original case studies. Our methodology balanced trade-offs between developing highly customized models for a few species versus fitting non-specific and generic models...
By
Fort Collins Science Center

Thresholded abundance models for three invasive plant species in the United States Thresholded abundance models for three invasive plant species in the United States

We developed habitat suitability models for three invasive plant species: stiltgrass (Microstegium vimineum), sericea lespedeza (Lespedeza cuneata), and privet (Ligustrum sinense). We applied the modeling workflow developed in Young et al. 2020, developing similar models for occurrence data, but also models trained using species locations with percent cover ≥10%, ≥25%, and ≥50%. We chose...
By
Fort Collins Science Center

INHABIT species potential distribution across the contiguous United States (ver. 3.0, February 2023) INHABIT species potential distribution across the contiguous United States (ver. 3.0, February 2023)

We developed habitat suitability models for invasive plant species selected by Department of Interior land management agencies. We applied the modeling workflow developed in Young et al. 2020 to species not included in the original case studies. Our methodology balanced trade-offs between developing highly customized models for a few species versus fitting non-specific and generic models...
By
Fort Collins Science Center

Data on how Lepidium draba responds to damage of clones Data on how Lepidium draba responds to damage of clones

A greenhouse experiment was conducted to test the ability of the invasive clonal plant, Lepidium draba, to cope with damage to local and different ramets. The experiment was arranged in a fully factorial split-pot design that was blocked by bench position and provenance population of the plant. Plants were grown in 'split pots', where two adjoining pots were glued together with a small...
By
Fort Collins Science Center

Data on grasshopper composition in the Thunder Basin National Grassland, Wyoming, USA Data on grasshopper composition in the Thunder Basin National Grassland, Wyoming, USA

Grasshopper biomass and species-level diversity was recorded at locations on and off prairie dog colonies in the Thunder Basin National Grassland, Wyoming, USA. Data were collected in order to record the association between grasshopper communities and prairie dog colonies.
By
Fort Collins Science Center

Data for a lab study of the effects of diet variability on the interactions between a Lepidopteran herbivore and its parasitoid Data for a lab study of the effects of diet variability on the interactions between a Lepidopteran herbivore and its parasitoid

Data were collected from two laboratory rearing experiments conducted in 2018 of Trichoplusia ni caterpillars that had been parasitized by Copidosoma floridanum parasitoids. In the first experiment, parasitized caterpillars were fed artificial diets spiked with increasing concentrations of the phytochemical xanthotoxin in order to assess the effect of xanthotoxin on parasitoid success...
By
Fort Collins Science Center
three spiny yellow balls attached to the underside of an oak tree leaf
Hedgehog galls on a chinquapin oak tree leaf
Hedgehog galls on a chinquapin oak tree leaf
three spiny yellow balls attached to the underside of an oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls (Acraspis prinoides) on the underside of a chinquapin oak. Photo by Ian Pearse (USGS).

By
Fort Collins Science Center
three spiny yellow balls attached to the underside of an oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls (Acraspis prinoides) on the underside of a chinquapin oak. Photo by Ian Pearse (USGS).

By
Fort Collins Science Center
brown fuzzy balls growing on the underside of an oak tree leaf, leaf held by a thumb and finger
Oak flake galls on an oak tree leaf
Oak flake galls on an oak tree leaf
brown fuzzy balls growing on the underside of an oak tree leaf, leaf held by a thumb and finger

Oak flake galls on an oak tree leaf

Oak flake galls on an oak tree leaf

Oak flake gall wasp (Neuroterus quercusverrucarum) galls on the underside of an oak tree leaf. Photo by Ian Pearse (USGS)

By
Fort Collins Science Center
brown fuzzy balls growing on the underside of an oak tree leaf, leaf held by a thumb and finger

Oak flake galls on an oak tree leaf

Oak flake galls on an oak tree leaf

Oak flake gall wasp (Neuroterus quercusverrucarum) galls on the underside of an oak tree leaf. Photo by Ian Pearse (USGS)

By
Fort Collins Science Center
two brown balls growing on top of a stem
Bullet galls on a bur oak stem
Bullet galls on a bur oak stem
two brown balls growing on top of a stem

Bullet galls on a bur oak stem

Bullet galls on a bur oak stem

A bullet gall (Discholcaspis quercusmamma) on a bur oak stem. Photo by Ian Pearse (USGS). 

By
Fort Collins Science Center
two brown balls growing on top of a stem

Bullet galls on a bur oak stem

Bullet galls on a bur oak stem

A bullet gall (Discholcaspis quercusmamma) on a bur oak stem. Photo by Ian Pearse (USGS). 

By
Fort Collins Science Center
Filter Total Items: 74

U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward

This “U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward” (“Pollinator Science Strategy”) describes the science vision of the U.S. Geological Survey (USGS) to support management, conservation, and policy decisions on animal pollinators and their habitats. As the science arm of the Department of the Interior, the USGS has a primary role in providing...
Authors
Clint R.V. Otto, Tabitha A. Graves, Desi Robertson-Thompson, Ian Pearse, Wayne E. Thogmartin, Caroline Murphy, Lisa Webb, Sam Droege, Melanie Steinkamp, Ralph Grundel
By
Ecosystems Mission Area, Cooperative Research Units, Species Management Research Program, Eastern Ecological Science Center, Fort Collins Science Center, Great Lakes Science Center, Northern Prairie Wildlife Research Center, Northern Rocky Mountain Science Center, Upper Midwest Environmental Sciences Center, National Geospatial Technical Operations Center

A quantitative classification of the geography of non-native flora in the United States A quantitative classification of the geography of non-native flora in the United States

AimNon-native plants have the potential to harm ecosystems. Harm is classically related to their distribution and abundance, but this geographical information is often unknown. Here, we assess geographical commonness as a potential indicator of invasive status for non-native flora in the United States. Geographical commonness could inform invasion risk assessments across species and...
Authors
Bethany A. Bradley, Annette Evans, Helen Sofaer, Montserrat Vilà, David Barnett, Evelyn M. Beaury, Dana M. Blumenthal, Jeffrey Corbin, Jeffrey Dukes, Regan Early, Ines Ibanez, Ian Pearse, Lais Petri, Cascade J.B. Sorte
By
Ecosystems Mission Area, John Wesley Powell Center for Analysis and Synthesis, Pacific Island Ecosystems Research Center

Using plant invasions to compare occurrence- and abundance-based calculations of biotic homogenisation: Are results complementary or contradictory? Using plant invasions to compare occurrence- and abundance-based calculations of biotic homogenisation: Are results complementary or contradictory?

AimBeta diversity quantifies the similarity of ecological assemblages. Its increase, known as biotic homogenisation, can be a consequence of biological invasions. However, species occurrence (presence/absence) and abundance-based analyses can produce contradictory assessments of the magnitude and direction of changes in beta diversity. Previous work indicates these contradictions should...
Authors
D.M. Buonaiuto, David Barnett, Dana M. Blumenthal, Andrea N. Nebhut, Ian Pearse, Helen Sofaer, Cascade J. B. Sorte, Jeffrey D. Corbin, Regan Early, Magda Garbowski, Ines Ibanez, Daniel C. Laughlin, Laís Petri, Montserrat Vilà, Bethany A. Bradley
By
Ecosystems Mission Area, Climate Adaptation Science Centers, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis, Pacific Island Ecosystems Research Center

How to model a new invader? US-invaded range models outperform global or combined range models after 100 occurrences How to model a new invader? US-invaded range models outperform global or combined range models after 100 occurrences

Invasive species are an economic and ecological burden, and efforts to limit their impact are greatly improved with reliable maps based on species distribution models (SDMs). However, the potential distribution of new invaders is difficult to anticipate because they are still spreading with few observations in their invaded habitat. Therefore, an accepted practice in predicting the...
Authors
Nicholas E. Young, Demetra A. Williams, Keana S. Shadwell, Ian Pearse, Catherine S. Jarnevich
By
Ecosystems Mission Area, Fort Collins Science Center

First records distribution models to guide biosurveillance for non-native species First records distribution models to guide biosurveillance for non-native species

Quickly locating new populations of non-native species can reduce the ecological and economic costs of species invasions. However, the difficulty of predicting which new non-native species will establish, and where, has limited active post-border biosurveillance efforts. Because pathways of introduction underlie spatial patterns of establishment risk, an intuitive approach is to search...
Authors
Helen Sofaer, Demetra A. Williams, Catherine S. Jarnevich, Keana S. Shadwell, Caroline Kittle, Ian Pearse, Lucas Fortini, Kelsey C. Brock
By
Ecosystems Mission Area, Fort Collins Science Center, Pacific Island Ecosystems Research Center

Predicted occurrence and abundance habitat suitability of invasive plants in the contiguous United States: Updates for the INHABIT web tool. Predicted occurrence and abundance habitat suitability of invasive plants in the contiguous United States: Updates for the INHABIT web tool.

Invasive plant species have substantial negative ecological and economic impacts. Geographic information on the potential and actual distributions of invasive plants is critical for their effective management. For many regions, numerous sources of predictive geographic information exist for invasive plants, often in the form of outputs from species distribution models (SDMs). The...
Authors
Catherine S. Jarnevich, Peder Engelstad, Demetra A. Williams, Keana S. Shadwell, Cameron J. Reimer, Grace Henderson, Janet S. Prevey, Ian Pearse
By
Ecosystems Mission Area, Fort Collins Science Center

Defining the pathobiomes associated with drippy blight in Colorado and drippy nut in California Defining the pathobiomes associated with drippy blight in Colorado and drippy nut in California

Drippy blight, an emergent bacterial disease of oaks, was described recently from urban oaks in the Front Range of Colorado, U.S.A. This disease, which causes branch dieback and oozing of bacterial exudates from cankers, is caused by Lonsdalea quercina and primarily affects red oaks, with northern red oak (Quercus rubra) being the most susceptible. Drippy nut is a similar, less acute...
Authors
Hope Raymond, Rachael Sitz, Ian Pearse, Jorge Caballero Ibarra, Brad Lalande, Jane Stewart
By
Ecosystems Mission Area, Fort Collins Science Center

Phenology forecasting models for detection and management of invasive annual grasses Phenology forecasting models for detection and management of invasive annual grasses

Non-native annual grasses can dramatically alter fire frequency and reduce forage quality and biodiversity in the ecosystems they invade. Effective management techniques are needed to reduce these undesirable invasive species and maintain ecosystem services. Well-timed management strategies, such as grazing, that are applied when invasive grasses are active prior to native plants can...
Authors
Janet S. Prevey, Ian Pearse, Dana M. Blumenthal, Armin J. Howell, Julie A. Kray, Sasha C. Reed, Mitchell B. Stephenson, Catherine S. Jarnevich
By
Ecosystems Mission Area, Fort Collins Science Center, Southwest Biological Science Center

The relationship between maturation size and maximum tree size from tropical to boreal climates The relationship between maturation size and maximum tree size from tropical to boreal climates

The fundamental trade-off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a proportionately larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain unavailable and we lack a global view on the generality and the shape of this trade-off...
Authors
Valentin Journé, Michał Bogdziewicz, Benoit Courbaud, Georges Kunstler, Tong Qiu, Marie-Claire Aravena Acuña, Davide Ascoli, Yves Bergeron, Daniel Berveiller, Thomas Boivin, Raul Bonal, Thomas Caignard, Maxime Cailleret, Rafael Calama, J. Julio Camarero, Chia-Hao Chang-Yang, Jerome Chave, Francesco Chianucci, Thomas Curt, Andrea Cutini, Adrian Das, Evangelia Daskalakou, Hendrik Davi, Nicolas Delpierre, Sylvain Delzon, Michael Dietze, Sergio Donoso Calderon, Laurent Dormont, Josep Maria Espelta, William Farfan-Rios, Michael Fenner, Jerry F. Franklin, Catherine A. Gehring, Gregory S. Gilbert, Georg Gratzer, Cathryn H. Greenberg, Arthur Guignabert, Qinfeng Guo, Andrew Hacket-Pain, Arndt Hampe, Qingmin Han, Mick E. Hanley, Janneke Hille Ris Lambers, Jan Holík, Kazuhiko Hoshizaki, Ines Ibanez, Jill F. Johnstone, Johannes M. H. Knops, Richard K. Kobe, Hiroko Kurokawa, Jonathan G. A. Lageard, Jalene LaMontagne, Mateusz Ledwon, François Lefèvre, Theodor Leininger, Jean-Marc Limousin, James A. Lutz, Diana Macias, Anders Mårell, Eliot J. B. McIntire, Emily V. Moran, Renzo Motta, Jonathan A. Myers, Thomas A. Nagel, Shoji Naoe, Mahoko Noguchi, Julian Norghauer, Michio Oguro, Jean-Marc Ourcival, Robert Parmenter, Ian Pearse, Ignacio M. Pérez-Ramos, Łukasz Piechnik, Tomasz Podgórski, John Poulsen, Miranda D. Redmond, Chantal D. Reid, Pavel Samonil, C. Lane Scher, William H. Schlesinger, Barbara Seget, Shubhi Sharma, Mitsue Shibata, Miles Silman, Michael A. Steele, Nathan L. Stephenson, Jacob N. Straub, Samantha Sutton, Jennifer J. Swenson, Margaret Swift, Peter A. Thomas, Maria Uriarte, Giorgio Vacchiano, Amy V. Whipple, Thomas G. Whitham, S. Joseph Wright, Kai Zhu, Jess K. Zimmerman, Magdalena Zywiec, James S. Clark
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Predictor importance in habitat suitability models for invasive terrestrial plants Predictor importance in habitat suitability models for invasive terrestrial plants

AimDue to the socioeconomic and environmental damages caused by invasive species, predicting the distribution of invasive plants is fundamental for effectively targeting management efforts. A habitat suitability model (HSM) is a powerful tool to predict potential habitat of invasive species to help guide the early detection of invasive plants. Despite numerous studies of the predictors...
Authors
Demetra A. Williams, Keana S. Shadwell, Ian Pearse, Janet S. Prevey, Peder Engelstad, Grace Henderson, Catherine S. Jarnevich
By
Ecosystems Mission Area, Fort Collins Science Center

Mast seeding in European beech (Fagus sylvatica L.) is associated with reduced fungal sporocarp production and community diversity Mast seeding in European beech (Fagus sylvatica L.) is associated with reduced fungal sporocarp production and community diversity

Mast seeding is a well-documented phenomenon across diverse forest ecosystems. While its effect on aboveground food webs has been thoroughly studied, how it impacts the soil fungi that drive soil carbon and nutrient cycling has not yet been explored. To evaluate the relationship between mast seeding and fungal resource availability, we paired a Swiss 29-year fungal sporocarp census with...
Authors
Talia Michaud, Ian Pearse, H Kauserud, Carrie Andrews, Peter Kennedy
By
Ecosystems Mission Area, Fort Collins Science Center

Evolutionary ecology of masting: Mechanisms, models, and climate change Evolutionary ecology of masting: Mechanisms, models, and climate change

Many perennial plants show mast seeding, characterized by synchronous and highly variable reproduction across years. We propose a general model of masting, integrating proximate factors (environmental variation, weather cues, and resource budgets) with ultimate drivers (predator satiation and pollination efficiency). This general model shows how the relationships between masting and...
Authors
Michal Bogdziewicz, Dave Kelly, Davide Ascoli, Thomas Caignard, Francesco Chianucci, Elizabeth E. Crone, Emilie Fleurot, Jessie Foest, Georg Gratzer, Tomika Hagiwara, Qingmin Han, Valentin Journé, Léa Keurinck, Katarzyna Kondrat, Ryan McClory, Jalene M. LaMontagne, Ignacio A. Mundo, Anita Nussbaumer, Iris Oberklammer, Misuzu Ohno, Ian Pearse, Mario B. Pesendorfer, Giulia Resente, Akiko Satake, Mitsue Shibata, Rebecca Snell, Jakub Szymkowiak, Laura Touzot, Rafał Zwolak, Magdalena Żywiec, Andrew Hacket-Pain
By
Ecosystems Mission Area, Fort Collins Science Center

Non-USGS Publications**

Pearse, I.S., Koenig, W.D., Kelly, D. 2016. Mechanisms of mast seeding: resources, weather, cues, and selection. The New Phytologist 212: 546-562
http://onlinelibrary.wiley.com/doi/10.1111/nph.14114/full
Mescher, M.C. and Pearse, I.S. 2016. Communicative interactions involving plants: information, evolution, and ecology Current Opinion in Plant Biology 32: 69-76. http://www.sciencedirect.com/science/article/pii/S136952661630098X
Krimmel, B.A., Pearse, I.S. 2016. Tolerance and phenological avoidance of herbivory in tarweed species. Ecology 97: 1357-1363. http://onlinelibrary.wiley.com/doi/10.1890/15-1454.1/full
Pesendorfer, M., Koenig, W.D., Pearse, I.S., Knops, J.M.H., Funk, K. 2016. Individual resource limitation combined with population-wide pollen availability drives masting in the valley oak (Quercus lobata). Journal of Ecology 104: 637-645.
http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12554/pdf
Moriera, X., Sampedro, L., Zas, R., Pearse, I.S. 2016. Defensive Traits in Young Pine Trees Cluster into Two Divergent Syndromes Related to Early Growth Rate. PlosOne. 0152537.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152537
Koenig, W.D., Alejano, R., Dolores Carbonero, M., Fernández-Rebollo, P., Knops, J.M.H, Maranon, T., Padilla-Diaz, C.M., Pearse, I.S., Perez-Ramon, I.M., Pesendorfer, M.B. 2016. Is the relationship between mast‐seeding and weather in oaks related to their life‐history or phylogeny? Ecology 97: 2603-2615. http://onlinelibrary.wiley.com/doi/10.1002/ecy.1490/full
Yguel, B., Jactel, H., Pearse, I.S., Moen, D., Winter, M., Hortal, J., Helmus, M., Kühn, I., Pavoine, S., Purschke, O., Weiher, E., Violle, C., Ozinga, W., Braendle M., Bartish I., Prinzing, A. 2016. The Evolutionary Legacy of Diversification Predicts Ecosystem Function. The American Naturalist. http://www.journals.uchicago.edu/doi/abs/10.1086/687964
Pearse, I.S., Koenig, W.D., Funk, K.A., Presendorfer, M.B. 2015. Pollen limitation and flower abortion in a wind-pollinated, masting tree. Ecology 96: 587-593
http://onlinelibrary.wiley.com/doi/10.1890/14-0297.1/ful
Koenig, W.D., Knops, J.M.H., Carmen, W.J., Pearse, I.S. 2015. What drives masting? The phenological synchrony hypothesis. Ecology 96: 184-192. http://onlinelibrary.wiley.com/doi/10.1890/14-0819.1/full
McMahon, D., Pearse, I.S., Koenig, W.D., Walters, E.L. 2015. Oak community shift and woodpecker population increase over three decades in California woodland. Canadian Journal of Forest Research. http://www.nrcresearchpress.com/doi/abs/10.1139/cjfr-2015-0035#.V__Zq_krJ9M
LoPresti, E.F., Pearse, I.S., Charles, G.K. 2015. A plant siren song: columbines provision mutualist arthropods by attracting and killing passerby insects. Ecology (featured in Science and Discover Magazine)
http://onlinelibrary.wiley.com/doi/10.1890/15-0342.1/full
Pearse, I.S., Altermatt, F. 2015. Out of sample predictions from plant-insect food webs: robustness to missing and erroneous trophic interaction records. Ecological Applications. http://onlinelibrary.wiley.com/doi/10.1890/14-1463.1/full
Pearse, I.S., Baty, J.H., Herrmann, D.L., Sage, R., Koenig, W.D. 2015. Leaf phenology mediates provenance differences in herbivore populations on valley oaks in a common garden. Ecological Entomology. http://onlinelibrary.wiley.com/doi/10.1111/een.12219/full
Hughes, K.A., Pearse, I.S., Gof-Tizsa, P., Karban, R. 2015. Individual-level differences in generalist caterpillar responses to a plant-plant signal. Ecological Entomology. http://onlinelibrary.wiley.com/doi/10.1111/een.12224/full
Pearse, I.S., Funk, K.A., Kraft, T.S., Koenig, W.D. 2015. Lagged effects of early‑season herbivores on valley oak fecundity. Oecologia 178: 361-368. http://link.springer.com/article/10.1007/s00442-014-3193-2
Petchey, O.L., Pontarp, M., Massie, T.N., Kéfi, S., Ozgul, A., Weilenmann, M., Palamara, G.C., Altermatt, F., Matthews, B.J., Levine, J.M., Childs, D.Z., McGill, B.J., Schaepman, M.E., Schmid, B., Spaak, P., Beckerman, A.P., Pennekamp, F., Pearse, I.S. 2015. The Ecological Forecast Horizon, and examples of its uses and determinants. Ecology Letters. http://onlinelibrary.wiley.com/doi/10.1111/ele.12443/full
Pearse, I.S., Hipp, A.L. 2014. Native plant diversity increases herbivory to non-natives. Proceedings of the Royal Society – B 281: 20141841. http://rspb.royalsocietypublishing.org/content/281/1794/20141841.short
Desurmont, G., Pearse, I.S. Alien plants versus alien herbivores: does it matter who is non-native in a novel trophic interaction? Current Opinion in Insect Science 2: 20-25. http://www.sciencedirect.com/science/article/pii/S221457451400035
Krimmel, B.A., Pearse, I.S. 2014. Generalist and sticky plant specialist predators suppress herbivores on a sticky plant. Arthropod Plant Interactions 8: 403-410. http://link.springer.com/article/10.1007/s11829-014-9318-z
Pearse, I.S., Cobb, R.C., Karban, R. 2014. The phenology substrate match hypothesis explains decomposition rates of evergreen and deciduous oak leaves. Journal of Ecology 102: 28-35. http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12182/full
Koenig, W.D., Walters, E.L., Pearse, I.S., Knops, J.M.H. 2014. Serotiny in California oaks. Madroño 61(2): 151-158. http://www.bioone.org/doi/full/10.3120/0024-9637-61.2.151
Pearse, IS, Koenig, WD, Knops, JMH. 2014. Cues versus proximate drivers: testing the mechanism behind masting behavior. Oikos 123: 179-184 http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0706.2013.00608.x/full
Karban, R., Huntzinger, M., Pearse, I.S. 2014. How to Do Ecology: A Concise Handbook, 2nd edition. Princeton University Press, Princeton. http://press.princeton.edu/titles/10284.html
Pearse, I.S., Bastow, J.L., Tsang, A. 2014. Radish introduction affects soil biota but has a positive impact on the growth of a native plant. Oecologia 174: 471-478. http://link.springer.com/article/10.1007/s00442-013-2779-4
Pearse, I.S., Griswold, S., Pizarro, D., Koenig, W.D. 2014. Stage and size structure of three species of oaks in central coastal California. Madroño 61(1): 1-8. http://www.bioone.org/doi/abs/10.3120/0024-9637-61.1.1
Pearse, I.S., Gee, W.S., Beck, J.J. 2013. Headspace volatiles from 52 oak species advertise induction, species identity, and evolution, but not defense. Journal of Chemical Ecology 39: 90-100. http://link.springer.com/article/10.1007/s10886-012-0224-5
Pearse, I.S. and Altermatt, F. 2013. Extinction cascades partially estimate observed herbivore losses in a Lepidoptera-plant food web. Ecology 94(8): 1785-1794 (Cover article). http://onlinelibrary.wiley.com/doi/10.1890/12-1075.1/full
Pearse, I.S., Hughes, K., Shiojiri, K., Ishizaki, S., Karban, R. 2013. Interplant volatile signaling in willows: revisiting the original talking trees. Oecologia 172: 869-875 (Cover article). http://link.springer.com/article/10.1007/s00442-013-2610-2
Pearse, I.S. and Karban, R. 2013. Leaf drop affects herbivory in oaks. Oecologia 173: 925-932. http://link.springer.com/article/10.1007/s00442-013-2689-5
Pearse, I.S., Harris, D.J., Karban, R., Sih, A. 2013.Predicting novel herbivore-plant interactions. Oikos 122: 1554-1564. http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0706.2013.00527.x/full
Pearse, I.S. and Altermatt F. 2013. Predicting novel trophic interactions in a non-native world. Ecology Letters 16: 1088-1094. http://onlinelibrary.wiley.com/doi/10.1111/ele.12143/full
Krimmel, B.A. and Pearse, I.S. 2013. Sticky plants trap invertebrate carrion to enhance indirect defense. Ecology Letters. 16: 219-224 (featured in Nature). http://onlinelibrary.wiley.com/doi/10.1111/ele.12032/full
Savchenko, T., Pearse, I.S., Karban, R., DeHesh, K. 2013. Insect feeding habits determine the composition of hydroperoxide lyase-derived metabolites. The Plant Journal 73: 653-662. http://onlinelibrary.wiley.com/doi/10.1111/tpj.12064/full
Pearse, I.S., Karban, R. 2013. Do plant-plant signals mediate herbivory consistently in multiple taxa and ecological contexts? Journal of Plant Interactions 8(3): 203-206. http://www.tandfonline.com/doi/abs/10.1080/17429145.2013.765511
Pearse, I.S. and Hipp, A.L. 2012. Global patterns of leaf defenses in oak species. Evolution. 66(7): 2272-2286. http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2012.01591.x/full
Herrmann, D.L., Pearse, I.S., Baty, J.H. 2012. Drivers of specialist herbivore diversity across 10 cities. Landscape and Urban Planning 108: 123-130. http://www.sciencedirect.com/science/article/pii/S0169204612002617
Pearse, I.S., Parensky, L.M., Yang, L.H., Stanton, M.L., Karban, R., Bhattacharyya, L., Dove, K., Higgins, A., Kamaroff, C., Kirk, T., Knight, C., Koch, R., Rollins, H., Tanner, K., Cox, R. 2012. Complex consequences of herbivory and interplant cues in three annual plants. PlosOne 7(5): e38105. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0038105
Pearse, I.S. and Baty, J.H. 2012. The predictability of traits and ecological interactions on 17 different crosses of hybrid oaks. Oecologia 169: 489-497. http://link.springer.com/article/10.1007/s00442-011-2216-5
Pearse, I.S. 2012. The role of leaf defensive traits in oaks on the preference and performance of a polyphagous herbivore, Orgyia vetusta. Ecological Entomology 36(5): 635-642. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2311.2011.01308.x/full
Altermatt, F., Pearse, I.S. 2011. Similarity and specialization of the larval versus adult diets of European butterflies and moths. The American Naturalist 178(3): 372-378. http://www.jstor.org/stable/10.1086/661248?seq=1#page_scan_tab_contents
Joseph, M., Gentles, M., Pearse, I.S. 2011. The parasitoid community of Andricus quercuscalifornicus (Hymenoptera: Cynipidae) is associated with gall size and host phenology. Biodiversity and Conservation 20: 203-216.
http://link.springer.com/article/10.1007/s10531-010-9956-0
Pearse I.S. 2011. Novel herbivore-plant interactions: Evidence from non-native oaks (Dissertation) U. California – Davis. http://gradworks.umi.com/34/99/3499479.html
Pearse, I.S. 2010. Bird rookeries have different effects on different feeding guilds of herbivores and alter the feeding behavior of a common caterpillar. Arthropod Plant Interactions 4: 189-195. http://link.springer.com/article/10.1007/s11829-010-9098-z
Karban, R., C. Karban, Huntzinger, M., Pearse, I., Crutsinger, G. 2010. Diet mixing enhances the performance of a generalist caterpillar, Platyprepia virginalis. Ecological Entomology 35(1): 92-99. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2311.2009.01162.x/full
Pearse, I.S. and A.L. Hipp. 2009. Phylogenetic and trait similarity to a native species predict herbivory on non-native oaks. Proceedings of the National Academy of Sciences of the United States of America 106(43): 18097-18102. (Cover article)
http://www.pnas.org/content/106/43/18097.short
Pearse, I, Zhu, Y, Murray, E, Dudeja, P, Ramaswamy, K, Malakooti, J. 2007. Sp1 and Sp3 control constitutive expression of the human NHE2 promoter by interactions with the proximal promoter and the transcription initiation site. Biochemical Journal 407: 101-111. http://www.biochemj.org/content/407/1/101.abstract
Pearse, IS, Krügel, T, Baldwin, IS. 2006. Innovation in anti-herbivore defense systems during neopolyploidy - the functional consequences of instantaneous speciation. The Plant Journal 47: 196-210. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2006.02776.x/full
Pearse, I.S., Heath, K.D., Cheeseman, J.M. 2006. Biochemical and ecological characterization of two peroxidase isoenzymes from the mangrove, Rhizophora mangle. Plant, Cell and Environment 28: 612-622 (Cover article).
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2005.01307.x/full

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward

U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward

This report describes the science vision of the USGS from 2025 to 2035 to support management, conservation, and decisions on animal pollinators and...

Read Article
Gall watching is the new bird watching

Gall watching is the new bird watching

Looking for a new hobby? When plants are infested by certain organisms, they produce abnormal plant tissue growths known as galls. But how do you know...

Read Article
Mapping hotspots of first detections of non-native species

Mapping hotspots of first detections of non-native species

Every non-native species has a first record – the first place it was reported to occur in the wild in its non-native range. By analyzing the...

Read Article
Stopping invaders at the doorstep: FORT researchers launch version 4.0 of the Invasive Species Habitat Tool

Stopping invaders at the doorstep: FORT researchers launch version 4.0 of the Invasive Species Habitat Tool

In a new version of the Invasive Species Habitat Tool (INHABIT 4.0), USGS scientists worked with resource managers to update the tool with occurrence...

Read Article
Predicting when the grass is greener: new phenological forecasts for invasive annual grasses

Predicting when the grass is greener: new phenological forecasts for invasive annual grasses

Two major hurdles in the effective control of invasive grasses are: (1) Anticipating the timing of key stages that are susceptible to management...

Read Article
Non-native plants consistently drive changes in functional traits of plant communities

Non-native plants consistently drive changes in functional traits of plant communities

Non-native plants have specific traits that cause consistent and predictable changes across ecosystems that can lead to wide-ranging changes in...

Read Article
Scientists discover genetically isolated populations and population-level inbreeding in a range-wide genetic analysis of the endangered rusty patched bumble bee

Scientists discover genetically isolated populations and population-level inbreeding in a range-wide genetic analysis of the endangered rusty patched bumble bee

Range-wide genetic analysis of the endangered rusty patched bumble bee shows surprising levels of inbreeding within populations and genetic divergence...

Read Article
In a recently published study, FORT scientists and collaborators synthesize data from 26,729 post-burn vegetation plots to determine the effects of fire and climate on non-native plant invasion

In a recently published study, FORT scientists and collaborators synthesize data from 26,729 post-burn vegetation plots to determine the effects of fire and climate on non-native plant invasion

This publication examined patterns and predictors of non-native plant invasion following fire across the western United States by synthesizing data...

Read Article
FORT ecologist Ian Pearse organizes workshop to support monitoring of an endangered bumble bee.

FORT ecologist Ian Pearse organizes workshop to support monitoring of an endangered bumble bee.

FORT ecologist Ian Pearse organized a workshop with the US Fish and Wildlife Service (Jan 9-11) to develop a monitoring program for the endangered...

Read Article
FORT Scientists Discuss Research at the 2023 Ecological Society of America Meeting

FORT Scientists Discuss Research at the 2023 Ecological Society of America Meeting

FORT researchers will be presenting at the 2023 Ecological Society of America (ESA) Conference in Portland, OR from August 6-11. The theme of this...

Read Article
Field Research for the Benefit of Bees

Field Research for the Benefit of Bees

USGS scientists take on the task of surveying native bee populations to understand what may put native bees at risk, and how to help them.  

Read Article
Fort Collins Science Center Scientists Share Expertise at Society for Range Management Meeting

Fort Collins Science Center Scientists Share Expertise at Society for Range Management Meeting

Scientists from the US Geological Survey Fort Collins Science Center will be presenting on topics ranging from sage-grouse to invasive plant species...

Read Article

Science and Products

USGS

Scaling-up phenological date matching for invasive species mapping: a free opensource workflow

Matching imagery dates to phenological events across large geographic regions for invasive species mapping.
By
Community for Data Integration (CDI)
Scaling-up phenological date matching for invasive species mapping: a free opensource workflow

Scaling-up phenological date matching for invasive species mapping: a free opensource workflow

Matching imagery dates to phenological events across large geographic regions for invasive species mapping.
Learn More
a website with sidebar on the left and buttons, a map of the united states, and a color key

INHABIT: A web tool for invasive plant management across the contiguous United States

INHABIT is a desktop-optimized web application and decision support tool with mapped and tabular summaries of habitat suitability models for over two hundred fifty terrestrial invasive plant species of management concern across the contiguous United States. It is the product of a scientist-practitioner partnership and is designed to facilitate enhanced invasive species management actions...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
INHABIT: A web tool for invasive plant management across the contiguous United States

INHABIT: A web tool for invasive plant management across the contiguous United States

INHABIT is a desktop-optimized web application and decision support tool with mapped and tabular summaries of habitat suitability models for over two hundred fifty terrestrial invasive plant species of management concern across the contiguous United States. It is the product of a scientist-practitioner partnership and is designed to facilitate enhanced invasive species management actions...
Learn More
photo of dry grasses

Predicting risk of annual grass invasion following fire in sagebrush steppe and rangeland ecosystems

This project analyzes on-the-ground plant monitoring data across sagebrush and rangeland ecosystems to examine how fire, climate, topography, and plant communities influence the success of invasive annual grasses after fires.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Land Management Research Program, Fort Collins Science Center, Wildland Fire Science
Predicting risk of annual grass invasion following fire in sagebrush steppe and rangeland ecosystems

Predicting risk of annual grass invasion following fire in sagebrush steppe and rangeland ecosystems

This project analyzes on-the-ground plant monitoring data across sagebrush and rangeland ecosystems to examine how fire, climate, topography, and plant communities influence the success of invasive annual grasses after fires.
Learn More
close-up of cheatgrass stalk in a field of cheatgrass

Predicting the phenology of invasive grasses under a changing climate to inform mapping and management

Cheatgrass, an invasive annual grass, reduces ecosystem productivity, negatively impacts biodiversity, and is increasingly problematic in higher elevation ecosystems with climate change. Cheatgrass phenology (that is, the timing of yearly growth and lifespan) varies greatly with elevation, climate, and weather from year to year, which can make management planning difficult and reduce the ability...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
Predicting the phenology of invasive grasses under a changing climate to inform mapping and management

Predicting the phenology of invasive grasses under a changing climate to inform mapping and management

Cheatgrass, an invasive annual grass, reduces ecosystem productivity, negatively impacts biodiversity, and is increasingly problematic in higher elevation ecosystems with climate change. Cheatgrass phenology (that is, the timing of yearly growth and lifespan) varies greatly with elevation, climate, and weather from year to year, which can make management planning difficult and reduce the ability...
Learn More
Image Collage of Landsat, pollinator, and volcanologist

Developing a macroecological understanding of invasive plant impacts based on abundance and trait data

Understanding invasive plant impacts can provide insight into community assembly and inform the development of successful management strategies. The impacts of invasive species depend on how they alter patterns of abundance within recipient communities and on the characteristics of the invaders and the affected species. Research has suggested that common species may be more impacted by...
By
John Wesley Powell Center for Analysis and Synthesis
Developing a macroecological understanding of invasive plant impacts based on abundance and trait data

Developing a macroecological understanding of invasive plant impacts based on abundance and trait data

Understanding invasive plant impacts can provide insight into community assembly and inform the development of successful management strategies. The impacts of invasive species depend on how they alter patterns of abundance within recipient communities and on the characteristics of the invaders and the affected species. Research has suggested that common species may be more impacted by invasions,
Learn More
Filter Total Items: 28

Data to fit habitat suitability models at different invasion stages and their results to evaluate model decisions Data to fit habitat suitability models at different invasion stages and their results to evaluate model decisions

This is a dataset containing the input and output data used in the analysis of best practices of invasive plant species distribution modeling (Young et al. 2024). We developed habitat suitability models for 13 invasive plant species at a variety of geographic ranges and different invasion stages and modeling strategies to assess the impact of predictor quality, thinning resolution, and...
By
Fort Collins Science Center

Community level traits of invaded plant communities in the United States Community level traits of invaded plant communities in the United States

Data were compiled from large trait databases for functional above and belowground traits (e.g. specific leaf area, specific root length, etc) of plants in communities across the United States along with information about the degree to which invasive species dominate those communities.
By
Fort Collins Science Center

INHABIT species potential distribution across the contiguous United States (ver. 4.0, June 2024) INHABIT species potential distribution across the contiguous United States (ver. 4.0, June 2024)

This is a dataset containing the potential distribution of 259 invasive terrestrial plant species. We developed habitat suitability models for invasive plant species selected by Department of Interior land management agencies and other managers. We applied the modeling workflow developed in Young et al. (2020, https://doi.org/10.1371/journal.pone.0229253) and adapted by Jarnevich et al....
By
Fort Collins Science Center

Projections of post-fire cover of non-native short-lived grasses and forbs under current and future climate conditions Projections of post-fire cover of non-native short-lived grasses and forbs under current and future climate conditions

These data provide current and future projected post-fire invasion risk by non-native short-lived grasses and forbs based on vegetation cover data from 26,729 plots in the western United States that burned prior to being sampled. Projected post-fire invasion risk was calculated using random forests with gridded climate, soil, and topographic predictor variables following Prevéy et al....
By
Fort Collins Science Center

Population genetic analysis of the rusty patched bumble bee in extant locations in 2022 Population genetic analysis of the rusty patched bumble bee in extant locations in 2022

This is a dataset of locations and population genetic information based on microsatellite analysis of rusty patched bumble bee (Bombus affinis). Data were collected over the course of two years (2020 and 2021), and genetic analysis took place in 2022.
By
Fort Collins Science Center

Potential distribution of Japanese brome (Bromus japonicus) across the contiguous United States (October 2023) Potential distribution of Japanese brome (Bromus japonicus) across the contiguous United States (October 2023)

This is a dataset containing the potential distribution of Japanese brome (Bromus japonicus). We developed habitat suitability models for Japanese brome, as suggested by Department of Interior land management agencies. We applied the modeling workflow developed in Young et al. 2020 to species not included in the original case studies. Our methodology balanced trade-offs between...
By
Fort Collins Science Center

Management summary table for INHABIT species potential distribution across the contiguous United States: additional management units Management summary table for INHABIT species potential distribution across the contiguous United States: additional management units

We developed habitat suitability models for invasive plant species selected by Department of Interior land management agencies. We applied the modeling workflow developed in Young et al. 2020 to species not included in the original case studies. Our methodology balanced trade-offs between developing highly customized models for a few species versus fitting non-specific and generic models...
By
Fort Collins Science Center

Thresholded abundance models for three invasive plant species in the United States Thresholded abundance models for three invasive plant species in the United States

We developed habitat suitability models for three invasive plant species: stiltgrass (Microstegium vimineum), sericea lespedeza (Lespedeza cuneata), and privet (Ligustrum sinense). We applied the modeling workflow developed in Young et al. 2020, developing similar models for occurrence data, but also models trained using species locations with percent cover ≥10%, ≥25%, and ≥50%. We chose...
By
Fort Collins Science Center

INHABIT species potential distribution across the contiguous United States (ver. 3.0, February 2023) INHABIT species potential distribution across the contiguous United States (ver. 3.0, February 2023)

We developed habitat suitability models for invasive plant species selected by Department of Interior land management agencies. We applied the modeling workflow developed in Young et al. 2020 to species not included in the original case studies. Our methodology balanced trade-offs between developing highly customized models for a few species versus fitting non-specific and generic models...
By
Fort Collins Science Center

Data on how Lepidium draba responds to damage of clones Data on how Lepidium draba responds to damage of clones

A greenhouse experiment was conducted to test the ability of the invasive clonal plant, Lepidium draba, to cope with damage to local and different ramets. The experiment was arranged in a fully factorial split-pot design that was blocked by bench position and provenance population of the plant. Plants were grown in 'split pots', where two adjoining pots were glued together with a small...
By
Fort Collins Science Center

Data on grasshopper composition in the Thunder Basin National Grassland, Wyoming, USA Data on grasshopper composition in the Thunder Basin National Grassland, Wyoming, USA

Grasshopper biomass and species-level diversity was recorded at locations on and off prairie dog colonies in the Thunder Basin National Grassland, Wyoming, USA. Data were collected in order to record the association between grasshopper communities and prairie dog colonies.
By
Fort Collins Science Center

Data for a lab study of the effects of diet variability on the interactions between a Lepidopteran herbivore and its parasitoid Data for a lab study of the effects of diet variability on the interactions between a Lepidopteran herbivore and its parasitoid

Data were collected from two laboratory rearing experiments conducted in 2018 of Trichoplusia ni caterpillars that had been parasitized by Copidosoma floridanum parasitoids. In the first experiment, parasitized caterpillars were fed artificial diets spiked with increasing concentrations of the phytochemical xanthotoxin in order to assess the effect of xanthotoxin on parasitoid success...
By
Fort Collins Science Center
three spiny yellow balls attached to the underside of an oak tree leaf
Hedgehog galls on a chinquapin oak tree leaf
Hedgehog galls on a chinquapin oak tree leaf
three spiny yellow balls attached to the underside of an oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls (Acraspis prinoides) on the underside of a chinquapin oak. Photo by Ian Pearse (USGS).

By
Fort Collins Science Center
three spiny yellow balls attached to the underside of an oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls on a chinquapin oak tree leaf

Hedgehog galls (Acraspis prinoides) on the underside of a chinquapin oak. Photo by Ian Pearse (USGS).

By
Fort Collins Science Center
brown fuzzy balls growing on the underside of an oak tree leaf, leaf held by a thumb and finger
Oak flake galls on an oak tree leaf
Oak flake galls on an oak tree leaf
brown fuzzy balls growing on the underside of an oak tree leaf, leaf held by a thumb and finger

Oak flake galls on an oak tree leaf

Oak flake galls on an oak tree leaf

Oak flake gall wasp (Neuroterus quercusverrucarum) galls on the underside of an oak tree leaf. Photo by Ian Pearse (USGS)

By
Fort Collins Science Center
brown fuzzy balls growing on the underside of an oak tree leaf, leaf held by a thumb and finger

Oak flake galls on an oak tree leaf

Oak flake galls on an oak tree leaf

Oak flake gall wasp (Neuroterus quercusverrucarum) galls on the underside of an oak tree leaf. Photo by Ian Pearse (USGS)

By
Fort Collins Science Center
two brown balls growing on top of a stem
Bullet galls on a bur oak stem
Bullet galls on a bur oak stem
two brown balls growing on top of a stem

Bullet galls on a bur oak stem

Bullet galls on a bur oak stem

A bullet gall (Discholcaspis quercusmamma) on a bur oak stem. Photo by Ian Pearse (USGS). 

By
Fort Collins Science Center
two brown balls growing on top of a stem

Bullet galls on a bur oak stem

Bullet galls on a bur oak stem

A bullet gall (Discholcaspis quercusmamma) on a bur oak stem. Photo by Ian Pearse (USGS). 

By
Fort Collins Science Center
Filter Total Items: 74

U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward

This “U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward” (“Pollinator Science Strategy”) describes the science vision of the U.S. Geological Survey (USGS) to support management, conservation, and policy decisions on animal pollinators and their habitats. As the science arm of the Department of the Interior, the USGS has a primary role in providing...
Authors
Clint R.V. Otto, Tabitha A. Graves, Desi Robertson-Thompson, Ian Pearse, Wayne E. Thogmartin, Caroline Murphy, Lisa Webb, Sam Droege, Melanie Steinkamp, Ralph Grundel
By
Ecosystems Mission Area, Cooperative Research Units, Species Management Research Program, Eastern Ecological Science Center, Fort Collins Science Center, Great Lakes Science Center, Northern Prairie Wildlife Research Center, Northern Rocky Mountain Science Center, Upper Midwest Environmental Sciences Center, National Geospatial Technical Operations Center

A quantitative classification of the geography of non-native flora in the United States A quantitative classification of the geography of non-native flora in the United States

AimNon-native plants have the potential to harm ecosystems. Harm is classically related to their distribution and abundance, but this geographical information is often unknown. Here, we assess geographical commonness as a potential indicator of invasive status for non-native flora in the United States. Geographical commonness could inform invasion risk assessments across species and...
Authors
Bethany A. Bradley, Annette Evans, Helen Sofaer, Montserrat Vilà, David Barnett, Evelyn M. Beaury, Dana M. Blumenthal, Jeffrey Corbin, Jeffrey Dukes, Regan Early, Ines Ibanez, Ian Pearse, Lais Petri, Cascade J.B. Sorte
By
Ecosystems Mission Area, John Wesley Powell Center for Analysis and Synthesis, Pacific Island Ecosystems Research Center

Using plant invasions to compare occurrence- and abundance-based calculations of biotic homogenisation: Are results complementary or contradictory? Using plant invasions to compare occurrence- and abundance-based calculations of biotic homogenisation: Are results complementary or contradictory?

AimBeta diversity quantifies the similarity of ecological assemblages. Its increase, known as biotic homogenisation, can be a consequence of biological invasions. However, species occurrence (presence/absence) and abundance-based analyses can produce contradictory assessments of the magnitude and direction of changes in beta diversity. Previous work indicates these contradictions should...
Authors
D.M. Buonaiuto, David Barnett, Dana M. Blumenthal, Andrea N. Nebhut, Ian Pearse, Helen Sofaer, Cascade J. B. Sorte, Jeffrey D. Corbin, Regan Early, Magda Garbowski, Ines Ibanez, Daniel C. Laughlin, Laís Petri, Montserrat Vilà, Bethany A. Bradley
By
Ecosystems Mission Area, Climate Adaptation Science Centers, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis, Pacific Island Ecosystems Research Center

How to model a new invader? US-invaded range models outperform global or combined range models after 100 occurrences How to model a new invader? US-invaded range models outperform global or combined range models after 100 occurrences

Invasive species are an economic and ecological burden, and efforts to limit their impact are greatly improved with reliable maps based on species distribution models (SDMs). However, the potential distribution of new invaders is difficult to anticipate because they are still spreading with few observations in their invaded habitat. Therefore, an accepted practice in predicting the...
Authors
Nicholas E. Young, Demetra A. Williams, Keana S. Shadwell, Ian Pearse, Catherine S. Jarnevich
By
Ecosystems Mission Area, Fort Collins Science Center

First records distribution models to guide biosurveillance for non-native species First records distribution models to guide biosurveillance for non-native species

Quickly locating new populations of non-native species can reduce the ecological and economic costs of species invasions. However, the difficulty of predicting which new non-native species will establish, and where, has limited active post-border biosurveillance efforts. Because pathways of introduction underlie spatial patterns of establishment risk, an intuitive approach is to search...
Authors
Helen Sofaer, Demetra A. Williams, Catherine S. Jarnevich, Keana S. Shadwell, Caroline Kittle, Ian Pearse, Lucas Fortini, Kelsey C. Brock
By
Ecosystems Mission Area, Fort Collins Science Center, Pacific Island Ecosystems Research Center

Predicted occurrence and abundance habitat suitability of invasive plants in the contiguous United States: Updates for the INHABIT web tool. Predicted occurrence and abundance habitat suitability of invasive plants in the contiguous United States: Updates for the INHABIT web tool.

Invasive plant species have substantial negative ecological and economic impacts. Geographic information on the potential and actual distributions of invasive plants is critical for their effective management. For many regions, numerous sources of predictive geographic information exist for invasive plants, often in the form of outputs from species distribution models (SDMs). The...
Authors
Catherine S. Jarnevich, Peder Engelstad, Demetra A. Williams, Keana S. Shadwell, Cameron J. Reimer, Grace Henderson, Janet S. Prevey, Ian Pearse
By
Ecosystems Mission Area, Fort Collins Science Center

Defining the pathobiomes associated with drippy blight in Colorado and drippy nut in California Defining the pathobiomes associated with drippy blight in Colorado and drippy nut in California

Drippy blight, an emergent bacterial disease of oaks, was described recently from urban oaks in the Front Range of Colorado, U.S.A. This disease, which causes branch dieback and oozing of bacterial exudates from cankers, is caused by Lonsdalea quercina and primarily affects red oaks, with northern red oak (Quercus rubra) being the most susceptible. Drippy nut is a similar, less acute...
Authors
Hope Raymond, Rachael Sitz, Ian Pearse, Jorge Caballero Ibarra, Brad Lalande, Jane Stewart
By
Ecosystems Mission Area, Fort Collins Science Center

Phenology forecasting models for detection and management of invasive annual grasses Phenology forecasting models for detection and management of invasive annual grasses

Non-native annual grasses can dramatically alter fire frequency and reduce forage quality and biodiversity in the ecosystems they invade. Effective management techniques are needed to reduce these undesirable invasive species and maintain ecosystem services. Well-timed management strategies, such as grazing, that are applied when invasive grasses are active prior to native plants can...
Authors
Janet S. Prevey, Ian Pearse, Dana M. Blumenthal, Armin J. Howell, Julie A. Kray, Sasha C. Reed, Mitchell B. Stephenson, Catherine S. Jarnevich
By
Ecosystems Mission Area, Fort Collins Science Center, Southwest Biological Science Center

The relationship between maturation size and maximum tree size from tropical to boreal climates The relationship between maturation size and maximum tree size from tropical to boreal climates

The fundamental trade-off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a proportionately larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain unavailable and we lack a global view on the generality and the shape of this trade-off...
Authors
Valentin Journé, Michał Bogdziewicz, Benoit Courbaud, Georges Kunstler, Tong Qiu, Marie-Claire Aravena Acuña, Davide Ascoli, Yves Bergeron, Daniel Berveiller, Thomas Boivin, Raul Bonal, Thomas Caignard, Maxime Cailleret, Rafael Calama, J. Julio Camarero, Chia-Hao Chang-Yang, Jerome Chave, Francesco Chianucci, Thomas Curt, Andrea Cutini, Adrian Das, Evangelia Daskalakou, Hendrik Davi, Nicolas Delpierre, Sylvain Delzon, Michael Dietze, Sergio Donoso Calderon, Laurent Dormont, Josep Maria Espelta, William Farfan-Rios, Michael Fenner, Jerry F. Franklin, Catherine A. Gehring, Gregory S. Gilbert, Georg Gratzer, Cathryn H. Greenberg, Arthur Guignabert, Qinfeng Guo, Andrew Hacket-Pain, Arndt Hampe, Qingmin Han, Mick E. Hanley, Janneke Hille Ris Lambers, Jan Holík, Kazuhiko Hoshizaki, Ines Ibanez, Jill F. Johnstone, Johannes M. H. Knops, Richard K. Kobe, Hiroko Kurokawa, Jonathan G. A. Lageard, Jalene LaMontagne, Mateusz Ledwon, François Lefèvre, Theodor Leininger, Jean-Marc Limousin, James A. Lutz, Diana Macias, Anders Mårell, Eliot J. B. McIntire, Emily V. Moran, Renzo Motta, Jonathan A. Myers, Thomas A. Nagel, Shoji Naoe, Mahoko Noguchi, Julian Norghauer, Michio Oguro, Jean-Marc Ourcival, Robert Parmenter, Ian Pearse, Ignacio M. Pérez-Ramos, Łukasz Piechnik, Tomasz Podgórski, John Poulsen, Miranda D. Redmond, Chantal D. Reid, Pavel Samonil, C. Lane Scher, William H. Schlesinger, Barbara Seget, Shubhi Sharma, Mitsue Shibata, Miles Silman, Michael A. Steele, Nathan L. Stephenson, Jacob N. Straub, Samantha Sutton, Jennifer J. Swenson, Margaret Swift, Peter A. Thomas, Maria Uriarte, Giorgio Vacchiano, Amy V. Whipple, Thomas G. Whitham, S. Joseph Wright, Kai Zhu, Jess K. Zimmerman, Magdalena Zywiec, James S. Clark
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Predictor importance in habitat suitability models for invasive terrestrial plants Predictor importance in habitat suitability models for invasive terrestrial plants

AimDue to the socioeconomic and environmental damages caused by invasive species, predicting the distribution of invasive plants is fundamental for effectively targeting management efforts. A habitat suitability model (HSM) is a powerful tool to predict potential habitat of invasive species to help guide the early detection of invasive plants. Despite numerous studies of the predictors...
Authors
Demetra A. Williams, Keana S. Shadwell, Ian Pearse, Janet S. Prevey, Peder Engelstad, Grace Henderson, Catherine S. Jarnevich
By
Ecosystems Mission Area, Fort Collins Science Center

Mast seeding in European beech (Fagus sylvatica L.) is associated with reduced fungal sporocarp production and community diversity Mast seeding in European beech (Fagus sylvatica L.) is associated with reduced fungal sporocarp production and community diversity

Mast seeding is a well-documented phenomenon across diverse forest ecosystems. While its effect on aboveground food webs has been thoroughly studied, how it impacts the soil fungi that drive soil carbon and nutrient cycling has not yet been explored. To evaluate the relationship between mast seeding and fungal resource availability, we paired a Swiss 29-year fungal sporocarp census with...
Authors
Talia Michaud, Ian Pearse, H Kauserud, Carrie Andrews, Peter Kennedy
By
Ecosystems Mission Area, Fort Collins Science Center

Evolutionary ecology of masting: Mechanisms, models, and climate change Evolutionary ecology of masting: Mechanisms, models, and climate change

Many perennial plants show mast seeding, characterized by synchronous and highly variable reproduction across years. We propose a general model of masting, integrating proximate factors (environmental variation, weather cues, and resource budgets) with ultimate drivers (predator satiation and pollination efficiency). This general model shows how the relationships between masting and...
Authors
Michal Bogdziewicz, Dave Kelly, Davide Ascoli, Thomas Caignard, Francesco Chianucci, Elizabeth E. Crone, Emilie Fleurot, Jessie Foest, Georg Gratzer, Tomika Hagiwara, Qingmin Han, Valentin Journé, Léa Keurinck, Katarzyna Kondrat, Ryan McClory, Jalene M. LaMontagne, Ignacio A. Mundo, Anita Nussbaumer, Iris Oberklammer, Misuzu Ohno, Ian Pearse, Mario B. Pesendorfer, Giulia Resente, Akiko Satake, Mitsue Shibata, Rebecca Snell, Jakub Szymkowiak, Laura Touzot, Rafał Zwolak, Magdalena Żywiec, Andrew Hacket-Pain
By
Ecosystems Mission Area, Fort Collins Science Center

Non-USGS Publications**

Pearse, I.S., Koenig, W.D., Kelly, D. 2016. Mechanisms of mast seeding: resources, weather, cues, and selection. The New Phytologist 212: 546-562
http://onlinelibrary.wiley.com/doi/10.1111/nph.14114/full
Mescher, M.C. and Pearse, I.S. 2016. Communicative interactions involving plants: information, evolution, and ecology Current Opinion in Plant Biology 32: 69-76. http://www.sciencedirect.com/science/article/pii/S136952661630098X
Krimmel, B.A., Pearse, I.S. 2016. Tolerance and phenological avoidance of herbivory in tarweed species. Ecology 97: 1357-1363. http://onlinelibrary.wiley.com/doi/10.1890/15-1454.1/full
Pesendorfer, M., Koenig, W.D., Pearse, I.S., Knops, J.M.H., Funk, K. 2016. Individual resource limitation combined with population-wide pollen availability drives masting in the valley oak (Quercus lobata). Journal of Ecology 104: 637-645.
http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12554/pdf
Moriera, X., Sampedro, L., Zas, R., Pearse, I.S. 2016. Defensive Traits in Young Pine Trees Cluster into Two Divergent Syndromes Related to Early Growth Rate. PlosOne. 0152537.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152537
Koenig, W.D., Alejano, R., Dolores Carbonero, M., Fernández-Rebollo, P., Knops, J.M.H, Maranon, T., Padilla-Diaz, C.M., Pearse, I.S., Perez-Ramon, I.M., Pesendorfer, M.B. 2016. Is the relationship between mast‐seeding and weather in oaks related to their life‐history or phylogeny? Ecology 97: 2603-2615. http://onlinelibrary.wiley.com/doi/10.1002/ecy.1490/full
Yguel, B., Jactel, H., Pearse, I.S., Moen, D., Winter, M., Hortal, J., Helmus, M., Kühn, I., Pavoine, S., Purschke, O., Weiher, E., Violle, C., Ozinga, W., Braendle M., Bartish I., Prinzing, A. 2016. The Evolutionary Legacy of Diversification Predicts Ecosystem Function. The American Naturalist. http://www.journals.uchicago.edu/doi/abs/10.1086/687964
Pearse, I.S., Koenig, W.D., Funk, K.A., Presendorfer, M.B. 2015. Pollen limitation and flower abortion in a wind-pollinated, masting tree. Ecology 96: 587-593
http://onlinelibrary.wiley.com/doi/10.1890/14-0297.1/ful
Koenig, W.D., Knops, J.M.H., Carmen, W.J., Pearse, I.S. 2015. What drives masting? The phenological synchrony hypothesis. Ecology 96: 184-192. http://onlinelibrary.wiley.com/doi/10.1890/14-0819.1/full
McMahon, D., Pearse, I.S., Koenig, W.D., Walters, E.L. 2015. Oak community shift and woodpecker population increase over three decades in California woodland. Canadian Journal of Forest Research. http://www.nrcresearchpress.com/doi/abs/10.1139/cjfr-2015-0035#.V__Zq_krJ9M
LoPresti, E.F., Pearse, I.S., Charles, G.K. 2015. A plant siren song: columbines provision mutualist arthropods by attracting and killing passerby insects. Ecology (featured in Science and Discover Magazine)
http://onlinelibrary.wiley.com/doi/10.1890/15-0342.1/full
Pearse, I.S., Altermatt, F. 2015. Out of sample predictions from plant-insect food webs: robustness to missing and erroneous trophic interaction records. Ecological Applications. http://onlinelibrary.wiley.com/doi/10.1890/14-1463.1/full
Pearse, I.S., Baty, J.H., Herrmann, D.L., Sage, R., Koenig, W.D. 2015. Leaf phenology mediates provenance differences in herbivore populations on valley oaks in a common garden. Ecological Entomology. http://onlinelibrary.wiley.com/doi/10.1111/een.12219/full
Hughes, K.A., Pearse, I.S., Gof-Tizsa, P., Karban, R. 2015. Individual-level differences in generalist caterpillar responses to a plant-plant signal. Ecological Entomology. http://onlinelibrary.wiley.com/doi/10.1111/een.12224/full
Pearse, I.S., Funk, K.A., Kraft, T.S., Koenig, W.D. 2015. Lagged effects of early‑season herbivores on valley oak fecundity. Oecologia 178: 361-368. http://link.springer.com/article/10.1007/s00442-014-3193-2
Petchey, O.L., Pontarp, M., Massie, T.N., Kéfi, S., Ozgul, A., Weilenmann, M., Palamara, G.C., Altermatt, F., Matthews, B.J., Levine, J.M., Childs, D.Z., McGill, B.J., Schaepman, M.E., Schmid, B., Spaak, P., Beckerman, A.P., Pennekamp, F., Pearse, I.S. 2015. The Ecological Forecast Horizon, and examples of its uses and determinants. Ecology Letters. http://onlinelibrary.wiley.com/doi/10.1111/ele.12443/full
Pearse, I.S., Hipp, A.L. 2014. Native plant diversity increases herbivory to non-natives. Proceedings of the Royal Society – B 281: 20141841. http://rspb.royalsocietypublishing.org/content/281/1794/20141841.short
Desurmont, G., Pearse, I.S. Alien plants versus alien herbivores: does it matter who is non-native in a novel trophic interaction? Current Opinion in Insect Science 2: 20-25. http://www.sciencedirect.com/science/article/pii/S221457451400035
Krimmel, B.A., Pearse, I.S. 2014. Generalist and sticky plant specialist predators suppress herbivores on a sticky plant. Arthropod Plant Interactions 8: 403-410. http://link.springer.com/article/10.1007/s11829-014-9318-z
Pearse, I.S., Cobb, R.C., Karban, R. 2014. The phenology substrate match hypothesis explains decomposition rates of evergreen and deciduous oak leaves. Journal of Ecology 102: 28-35. http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12182/full
Koenig, W.D., Walters, E.L., Pearse, I.S., Knops, J.M.H. 2014. Serotiny in California oaks. Madroño 61(2): 151-158. http://www.bioone.org/doi/full/10.3120/0024-9637-61.2.151
Pearse, IS, Koenig, WD, Knops, JMH. 2014. Cues versus proximate drivers: testing the mechanism behind masting behavior. Oikos 123: 179-184 http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0706.2013.00608.x/full
Karban, R., Huntzinger, M., Pearse, I.S. 2014. How to Do Ecology: A Concise Handbook, 2nd edition. Princeton University Press, Princeton. http://press.princeton.edu/titles/10284.html
Pearse, I.S., Bastow, J.L., Tsang, A. 2014. Radish introduction affects soil biota but has a positive impact on the growth of a native plant. Oecologia 174: 471-478. http://link.springer.com/article/10.1007/s00442-013-2779-4
Pearse, I.S., Griswold, S., Pizarro, D., Koenig, W.D. 2014. Stage and size structure of three species of oaks in central coastal California. Madroño 61(1): 1-8. http://www.bioone.org/doi/abs/10.3120/0024-9637-61.1.1
Pearse, I.S., Gee, W.S., Beck, J.J. 2013. Headspace volatiles from 52 oak species advertise induction, species identity, and evolution, but not defense. Journal of Chemical Ecology 39: 90-100. http://link.springer.com/article/10.1007/s10886-012-0224-5
Pearse, I.S. and Altermatt, F. 2013. Extinction cascades partially estimate observed herbivore losses in a Lepidoptera-plant food web. Ecology 94(8): 1785-1794 (Cover article). http://onlinelibrary.wiley.com/doi/10.1890/12-1075.1/full
Pearse, I.S., Hughes, K., Shiojiri, K., Ishizaki, S., Karban, R. 2013. Interplant volatile signaling in willows: revisiting the original talking trees. Oecologia 172: 869-875 (Cover article). http://link.springer.com/article/10.1007/s00442-013-2610-2
Pearse, I.S. and Karban, R. 2013. Leaf drop affects herbivory in oaks. Oecologia 173: 925-932. http://link.springer.com/article/10.1007/s00442-013-2689-5
Pearse, I.S., Harris, D.J., Karban, R., Sih, A. 2013.Predicting novel herbivore-plant interactions. Oikos 122: 1554-1564. http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0706.2013.00527.x/full
Pearse, I.S. and Altermatt F. 2013. Predicting novel trophic interactions in a non-native world. Ecology Letters 16: 1088-1094. http://onlinelibrary.wiley.com/doi/10.1111/ele.12143/full
Krimmel, B.A. and Pearse, I.S. 2013. Sticky plants trap invertebrate carrion to enhance indirect defense. Ecology Letters. 16: 219-224 (featured in Nature). http://onlinelibrary.wiley.com/doi/10.1111/ele.12032/full
Savchenko, T., Pearse, I.S., Karban, R., DeHesh, K. 2013. Insect feeding habits determine the composition of hydroperoxide lyase-derived metabolites. The Plant Journal 73: 653-662. http://onlinelibrary.wiley.com/doi/10.1111/tpj.12064/full
Pearse, I.S., Karban, R. 2013. Do plant-plant signals mediate herbivory consistently in multiple taxa and ecological contexts? Journal of Plant Interactions 8(3): 203-206. http://www.tandfonline.com/doi/abs/10.1080/17429145.2013.765511
Pearse, I.S. and Hipp, A.L. 2012. Global patterns of leaf defenses in oak species. Evolution. 66(7): 2272-2286. http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2012.01591.x/full
Herrmann, D.L., Pearse, I.S., Baty, J.H. 2012. Drivers of specialist herbivore diversity across 10 cities. Landscape and Urban Planning 108: 123-130. http://www.sciencedirect.com/science/article/pii/S0169204612002617
Pearse, I.S., Parensky, L.M., Yang, L.H., Stanton, M.L., Karban, R., Bhattacharyya, L., Dove, K., Higgins, A., Kamaroff, C., Kirk, T., Knight, C., Koch, R., Rollins, H., Tanner, K., Cox, R. 2012. Complex consequences of herbivory and interplant cues in three annual plants. PlosOne 7(5): e38105. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0038105
Pearse, I.S. and Baty, J.H. 2012. The predictability of traits and ecological interactions on 17 different crosses of hybrid oaks. Oecologia 169: 489-497. http://link.springer.com/article/10.1007/s00442-011-2216-5
Pearse, I.S. 2012. The role of leaf defensive traits in oaks on the preference and performance of a polyphagous herbivore, Orgyia vetusta. Ecological Entomology 36(5): 635-642. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2311.2011.01308.x/full
Altermatt, F., Pearse, I.S. 2011. Similarity and specialization of the larval versus adult diets of European butterflies and moths. The American Naturalist 178(3): 372-378. http://www.jstor.org/stable/10.1086/661248?seq=1#page_scan_tab_contents
Joseph, M., Gentles, M., Pearse, I.S. 2011. The parasitoid community of Andricus quercuscalifornicus (Hymenoptera: Cynipidae) is associated with gall size and host phenology. Biodiversity and Conservation 20: 203-216.
http://link.springer.com/article/10.1007/s10531-010-9956-0
Pearse I.S. 2011. Novel herbivore-plant interactions: Evidence from non-native oaks (Dissertation) U. California – Davis. http://gradworks.umi.com/34/99/3499479.html
Pearse, I.S. 2010. Bird rookeries have different effects on different feeding guilds of herbivores and alter the feeding behavior of a common caterpillar. Arthropod Plant Interactions 4: 189-195. http://link.springer.com/article/10.1007/s11829-010-9098-z
Karban, R., C. Karban, Huntzinger, M., Pearse, I., Crutsinger, G. 2010. Diet mixing enhances the performance of a generalist caterpillar, Platyprepia virginalis. Ecological Entomology 35(1): 92-99. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2311.2009.01162.x/full
Pearse, I.S. and A.L. Hipp. 2009. Phylogenetic and trait similarity to a native species predict herbivory on non-native oaks. Proceedings of the National Academy of Sciences of the United States of America 106(43): 18097-18102. (Cover article)
http://www.pnas.org/content/106/43/18097.short
Pearse, I, Zhu, Y, Murray, E, Dudeja, P, Ramaswamy, K, Malakooti, J. 2007. Sp1 and Sp3 control constitutive expression of the human NHE2 promoter by interactions with the proximal promoter and the transcription initiation site. Biochemical Journal 407: 101-111. http://www.biochemj.org/content/407/1/101.abstract
Pearse, IS, Krügel, T, Baldwin, IS. 2006. Innovation in anti-herbivore defense systems during neopolyploidy - the functional consequences of instantaneous speciation. The Plant Journal 47: 196-210. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2006.02776.x/full
Pearse, I.S., Heath, K.D., Cheeseman, J.M. 2006. Biochemical and ecological characterization of two peroxidase isoenzymes from the mangrove, Rhizophora mangle. Plant, Cell and Environment 28: 612-622 (Cover article).
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2005.01307.x/full

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward

U.S. Geological Survey Pollinator Science Strategy, 2025–35—A Review and Look Forward

This report describes the science vision of the USGS from 2025 to 2035 to support management, conservation, and decisions on animal pollinators and...

Read Article
Gall watching is the new bird watching

Gall watching is the new bird watching

Looking for a new hobby? When plants are infested by certain organisms, they produce abnormal plant tissue growths known as galls. But how do you know...

Read Article
Mapping hotspots of first detections of non-native species

Mapping hotspots of first detections of non-native species

Every non-native species has a first record – the first place it was reported to occur in the wild in its non-native range. By analyzing the...

Read Article
Stopping invaders at the doorstep: FORT researchers launch version 4.0 of the Invasive Species Habitat Tool

Stopping invaders at the doorstep: FORT researchers launch version 4.0 of the Invasive Species Habitat Tool

In a new version of the Invasive Species Habitat Tool (INHABIT 4.0), USGS scientists worked with resource managers to update the tool with occurrence...

Read Article
Predicting when the grass is greener: new phenological forecasts for invasive annual grasses

Predicting when the grass is greener: new phenological forecasts for invasive annual grasses

Two major hurdles in the effective control of invasive grasses are: (1) Anticipating the timing of key stages that are susceptible to management...

Read Article
Non-native plants consistently drive changes in functional traits of plant communities

Non-native plants consistently drive changes in functional traits of plant communities

Non-native plants have specific traits that cause consistent and predictable changes across ecosystems that can lead to wide-ranging changes in...

Read Article
Scientists discover genetically isolated populations and population-level inbreeding in a range-wide genetic analysis of the endangered rusty patched bumble bee

Scientists discover genetically isolated populations and population-level inbreeding in a range-wide genetic analysis of the endangered rusty patched bumble bee

Range-wide genetic analysis of the endangered rusty patched bumble bee shows surprising levels of inbreeding within populations and genetic divergence...

Read Article
In a recently published study, FORT scientists and collaborators synthesize data from 26,729 post-burn vegetation plots to determine the effects of fire and climate on non-native plant invasion

In a recently published study, FORT scientists and collaborators synthesize data from 26,729 post-burn vegetation plots to determine the effects of fire and climate on non-native plant invasion

This publication examined patterns and predictors of non-native plant invasion following fire across the western United States by synthesizing data...

Read Article
FORT ecologist Ian Pearse organizes workshop to support monitoring of an endangered bumble bee.

FORT ecologist Ian Pearse organizes workshop to support monitoring of an endangered bumble bee.

FORT ecologist Ian Pearse organized a workshop with the US Fish and Wildlife Service (Jan 9-11) to develop a monitoring program for the endangered...

Read Article
FORT Scientists Discuss Research at the 2023 Ecological Society of America Meeting

FORT Scientists Discuss Research at the 2023 Ecological Society of America Meeting

FORT researchers will be presenting at the 2023 Ecological Society of America (ESA) Conference in Portland, OR from August 6-11. The theme of this...

Read Article
Field Research for the Benefit of Bees

Field Research for the Benefit of Bees

USGS scientists take on the task of surveying native bee populations to understand what may put native bees at risk, and how to help them.  

Read Article
Fort Collins Science Center Scientists Share Expertise at Society for Range Management Meeting

Fort Collins Science Center Scientists Share Expertise at Society for Range Management Meeting

Scientists from the US Geological Survey Fort Collins Science Center will be presenting on topics ranging from sage-grouse to invasive plant species...

Read Article

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government

Was this page helpful?