Ian Pearse, Ph.D.
Ian Pearse is an ecologist in the invasive species branch of the Fort Collins Science Center.
Biography
Ian Pearse is a research ecologist at the Fort Collins Science Center. Ian received a Ph.D. in Entomology from U.C. Davis in 2011. He has conducted research on plant-insect interactions and community ecology, focusing on ways to predict new interactions between introduced species such as plants and herbivorous insects. As part of the invasive species branch, Ian is applying that work to anticipate the impacts of destructive plant and insect invasions.
Education
- Ph.D. University of California, Davis, 2011
- B.S. University of Illinois, 2004
Professional Experience
- 2016 Postdoctoral work, University of California, Davis
- 2014-2015 Postdoctoral work, Illinois Natural History Survey
- 2012-2013 Postdoctoral work, Cornell University
Science and Products
Greenhouse observations of plant herbivore interactions on Lepidium draba to test effects of ontogenic variability
Data were collected from an experimental greenhouse study in which Lepidium draba plants were grown from root cuttings to create plants at different ontogenic stages. Plants were arranged in mixed-age and single-age stands and exposed to the Lepidopteran herbivore, diamondback moth caterpillars. The success (biomass gain and surivival) of herbivores, the amount of feeding, and the gro
Californian crop pests, pesticide applications, and phylogenetic information of crops
Information on pesticide applications, crop pests, and phylogenetic affinities between Californian crops and regional native plants were compiled. Data was collected to inform models of pesticide applications and host use of pests among California's 93 major crops. Pesticide data was assembled from California Department of Pesticide Regulation records, pest information was assembled fro
Long-term Trends in Midwestern Milkweeds and their Relevance for Monarchs
This is the dataset used in the BioScience publication of the same name.
Direct and indirect effects of a keystone engineer on a shrubland-prairie food web
Keystone engineers are critical drivers of biodiversity throughout ecosystems worldwide. Within the North American Great Plains, the black‐tailed prairie dog is an imperiled ecosystem engineer and keystone species with well‐documented impacts on the flora and fauna of rangeland systems. However, because this species affects ecosystem structure and...
Duchardt, Courtney; Porensky, Lauren M.; Pearse, IanNegative 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, SusanPhylogenetic escape from pests reduces pesticides on some crop plants
Pesticides are a ubiquitous component of conventional crop production but come with considerable economic and ecological costs. We tested the hypothesis that variation in pesticide use among crop species is a function of crop economics and the phylogenetic relationship of a crop to native plants because unrelated crops accrue fewer herbivores and...
Pearse, Ian; Rosenheim, JayAssociational effects of plant ontogeny on damage by a specialist insect herbivore
Intraspecific variation in plant traits is a major cause of variation in herbivore feeding and performance. Plant defensive traits change as a plant grows, such that ontogeny may account for a substantial portion of intraspecific trait variation. We tested how the ontogenic stage of an individual plant, of an individual in the context of its...
Cope, Olivia; Becker, Zoe; Ode, Paul J.; Ryan, Paul; Pearse, IanGeneralizing indirect defense and resistance of plants
Indirect defence, the adaptive top‐down control of herbivores by plant traits that enhance predation, is a central component of plant–herbivore interactions. However, the scope of interactions that comprise indirect defence and associated ecological and evolutionary processes has not been clearly defined. We argue that the range of plant traits...
Pearse, Ian; LoPresti, Eric; Schaeffer, Robert N.; Wetzel, William C.; Mooney, Kailen A.; Ali, Jared G.; Ode, Paul J.; Eubanks, Micky D.; Bronstein, Judith L.; Weber, Marjorie G.Mast seeding patterns are asynchronous at a continental scale
Resource pulses are short duration, high magnitude, rare events that drive the dynamics of both plant and animal populations and communities1. Mast seeding is perhaps the most common type of resource pulse occurring in terrestrial ecosystems2, is characterized by the synchronous and highly variable production of seed crops by a population of...
LaMontagne, J. M.; Pearse, Ian; Greene, David A.; Koenig, W. D.Biogeography and phylogeny of masting: Do global patterns fit functional hypotheses?
1) Interannual variability of seed crops (CVp) has profound consequences for plant populations and food webs, where high CVp is termed ‘masting’. Here we ask: is global variation in CVp better predicted by plant or habitat differences consistent with adaptive economies of scale, in which flower and seed benefits increase disproportionately during...
Pearse, Ian; LaMontagne, Jalene; Lordon, Michael; Hipp, Andrew; Koenig, Walter D.Life-history plasticity and water-use trade-offs associated with drought resistance in a clade of California jewelflowers
Water limitation is a primary driver of plant geographic distributions and individual plant fitness. Drought resistance is the ability to survive and reproduce despite limited water, and numerous studies have explored its physiological basis in plants. However, it is unclear how drought resistance and trade-offs associated with drought resistance...
Pearse, Ian S.; Aguilar, Jessica; Strauss, SharonA 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.Population ecology and spatial synchrony in abundance within and among populations of valley oak (Quercus lobata) leaf gall wasps
What factors drive population variability through space and time? Here we assess patterns of abundance of seven species of gall wasps in three genera occurring on the leaves of valley oaks (Quercus lobata ) at 10 sites throughout this species' statewide range in California, from 2000 to 2006. Our primary goals were to understand the factors...
Barringer, Brian; Koenig, Walter D.; Pearse, Ian; Knops, JeanFrom theory to experiments for testing the proximate mechanisms of mast seeding: An agenda for an experimental ecology
Highly variable and synchronised production of seeds by plant populations is called masting and is implicated in many important ecological processes, but how it arises remains poorly understood. The lack of experimental studies prevents underlying mechanisms from being explicitly tested, and thereby precludes meaningful predictions on the...
Bogdziewicz, M.; Ascoli, Davide; Hacket-Pain, Andrew; Koenig, W. D.; Pearse, Ian; Pesendorfer, Mario B.; Satake, A.; Thomas, P.; Vacchiano, Giorgio; Wohlgemuth, T.; Tanentzap, A.Climate teleconnections synchronize Picea glauca masting and fire disturbance: Evidence for a fire‐related form of environmental prediction
Synchronous pulses of seed masting and natural disturbance have positive feedbacks on the reproduction of masting species in disturbance‐prone ecosystems. We test the hypotheses that disturbances and proximate causes of masting are correlated, and that their large‐scale synchrony is driven by similar climate teleconnection patterns at both inter‐...
Ascoli, Davide; Hacket-Pain, Andrew; LaMontagne, Jalene M.; Cardil, Adrian; Conedera, Marco; Maringer, Janet; Motta, Renzo; Pearse, Ian; Vacchiano, GiorgioPre-USGS Publications
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 at the upcoming Society for Range Management Annual Meeting.