Yvette K. Ortega
Ecologist
Wildlife and Terrestrial Ecosystems
800 East Beckwith Avenue
Missoula, MT 59801-5801
United States
Missoula, MT 59801-5801
United States
Phone
406-542-3246
Current Research
* Evaluate invader impacts at population and community levels, including underlying mechanisms. * Examine interactive impacts of drought and herbivory by biological control agents on the competitive dominance of a notorious weed. * Assess a new technique for assessing habitat quality for songbirds based on local song structure. * Measure effects of invasive plant control treatments on plants and animals and evaluate degree to which such methods mitigate target invader impacts.
Past Research
My past research includes examination of disturbance effects on harbor seals, edge effects of forest roads on songbirds, and habitat use of Canada lynx.
Research Interest
My primary interest lies in building understandings of ecological patterns and processes in order to improve the management of natural systems. Current applications include evaluating impacts of exotic plants on native plants, cascading effects on consumers, and efficacy of weed control efforts in mitigating these impacts. Studies consider population and community level attributes, and organisms from plants and invertebrate to birds and their predators.
Why This Research Is Important
My work aims to develop and apply ecological principles to solve real-world problems facing managers of natural systems.
Education
- University of California, Berkeley, B.A., Environmental Science, 1992
- University of Vermont, M.S., Wildlife and Fisheries Biology, 1998
Featured Publications
- Pearson, Dean E.; Ortega, Yvette K.; Runyon, Justin B.; Butler, Jack L.. 2016. Secondary invasion: The bane of weed management
- Pearson, Dean E.; Ortega, Yvette K.; Eren, Ozkan; Hierro, Jose L.. 2015. Quantifying "apparent" impact and distinguishing impact from invasiveness in multispecies plant invasions
- Ortega, Yvette K.; Benson, Aubree; Greene, Erick. 2014. Invasive plant erodes local song diversity in a migratory passerine
- Ortega, Yvette K.; Greenwood, Leigh F.; Callaway, Ragan M.; Pearson, Dean E.. 2014. Different responses of congeneric consumers to an exotic food resource: Who gets the novel resource prize?
- Ortega, Yvette K.; Pearson, Dean E.; Waller, Lauren P.; Sturdevant, Nancy J.; Maron, John L.. 2012. Population-level compensation impedes biological control of an invasive forb and indirect release of a native grass
- Ortega, Yvette K.; Pearson, Dean E.. 2011. Long-term effects of weed control with picloram along a gradient of spotted knapweed invasion
- Ortega, Yvette K.; Pearson, Dean E.. 2005. Weak vs. strong invaders of natural plant communities: Assessing invasibility and impact
- Ortega, Yvette K.; Pearson, Dean E.; McKelvey, Kevin S.. 2004. Effects of biological control agents and exotic plant invasion on deer mouse populations
Other Publications
- Pearson, Dean E.; Ortega, Yvette K.; Cimino, Hillary E.; Mummy, Daniel L.; Ramsey, Philip W.. 2022. Does active plant restoration passively restore native fauna community structure and function?
- Jang, Woongsoon ; Crotteau, Justin S.; Ortega, Yvette K.; Hood, Sharon M.; Keyes, Christopher R.; Pearson, Dean E.; Lutes, Duncan C.; Sala, Anna. 2021. Native and non-native understory vegetation responses to restoration treatments in a dry conifer forest over 23 years
- Zhong, Zhiwei ; Li, Xiaofei ; Sanders, Dirk ; Liu, Yiming ; Wang, Ling ; Ortega, Yvette K.; Pearson, Dean E.; Wang, Deli. 2021. Soil engineering by ants facilitates plant compensation for large herbivore removal of aboveground biomass
- Dylewski, Lukasz ; Ortega, Yvette K.; Bogdziewicz, Michal ; Pearson, Dean E.. 2021. Seed predator effects on plants: Moving beyond time-corrected proxies
- Dylewski, Lukasz ; Ortega, Yvette K.; Bogdziewics, Michal ; Pearson, Dean E.. 2020. Seed size predicts global effects of small mammal seed predation on plant recruitment
- Pearson, Dean E.; Valliant, Morgan ; Carlson, Chris ; Thelen, Giles C.; Ortega, Yvette K.; Orrock, John L.; Madsen, Matthew D.. 2019. Spicing up restoration: Can chili peppers improve restoration seeding by reducing seed predation?
- Ortega, Yvette K.; Valliant, Morgan T.; Pearson, Dean E.. 2019. To list or not to list: Using time since invasion to refine impact assessment for an exotic plant proposed as noxious
- Pearson, Dean E.; Eren, Ozkan ; Ortega, Yvette K.; Villarreal, Diego ; Senturk, Muhyettin ; Miguel, M. Florencia; Weinzettel, C. Miguel; Prina, Anibal ; Hierro, Jose L.. 2018. Are invasive plants more abundant in the introduced versus native range?
- Pearson, Dean E.; Ortega, Yvette K.; Villarreal, Diego ; Lekberg, Ylva ; Cock, Marina C.; Eren, Ozkan ; Hierro, Jose L.. 2018. The fluctuating resource hypothesis explains invasibility, but not exotic advantage following disturbance
- Pearson, Dean E.; Ortega, Yvette K.; Runyon, Justin ; Butler, Jack L.. 2018. Secondary invasion re-redefined: The distinction between invader-facilitated and invader-contingent invasions as subclasses of secondary invasion
- Pearson, Dean E.; Ortega, Yvette K.; Eren, Ozkan ; Hierro, Jose L.. 2018. Community assembly theory as a framework for biological invasions
- Pearson, Dean E.; Ortega, Yvette K.; Maron, John L.. 2017. The tortoise and the hare: Reducing resource availability shifts competitive balance between plant species
- Maron, John L.; Smith, Alyssa Laney; Ortega, Yvette K.; Pearson, Dean E.; Callaway, Ragan M.. 2016. Negative plant-soil feedbacks increase with plant abundance, and are unchanged by competition
- Pinto, Sarah M.; Ortega, Yvette K.. 2016. Native species richness buffers invader impact in undisturbed but not disturbed grassland assemblages
- Waller, Lauren P.; Callaway, Ragan M.; Klironomos, John N.; Ortega, Yvette K.; Maron, John L.. 2016. Reduced mycorrhizal responsiveness leads to increased competitive tolerance in an invasive exotic plant
- Pearson, Dean; Ortega, Yvette; Butler, Jack. 2015. Invasive Species Science Update (No. 8)
- Pearson, Dean; Ortega, Yvette; Butler, Jack. 2014. Invasive Species Science Update (No. 7)
- Pearson, Dean; Ortega, Yvette. 2013. Biogeography of plant invasions
- Ortega, Yvette; Pearson, Dean. 2013. Spotted knapweed: Effects of climate change on the invasiveness and biological control
- Zwolak, R.; Pearson, D. E.; Ortega, Y. K.; Crone, E. E.. 2012. Mechanisms driving postfire abundance of a generalist mammal
- Pearson, Dean E.; Ortega, Yvette K.; Sears, Samantha J.. 2012. Darwin's naturalization hypothesis up-close: Intermountain grassland invaders differ morphologically and phenologically from native community dominants
- Maron, John L.; Pearson, Dean E.; Potter, Teal; Ortega, Yvette K.. 2012. Seed size and provenance mediate the joint effects of disturbance and seed predation on community assembly
- Pearson, Dean; Ortega, Yvette. 2011. Invasive Species Science Update (No. 5)
- Zwolak, Rafal; Pearson, Dean E.; Ortega, Yvette K.; Crone, Elizabeth E.. 2010. Fire and mice: Seed predation moderates fire's influence on conifer recruitment
- Ortega, Yvete K.; Pearson, Dean E.. 2010. Effects of picloram application on community dominants vary with initial levels of spotted knapweed (Centaurea stoebe) invasion
- Pearson, Dean; Ortega, Yvette. 2009. Managing invasive plants in natural areas: Moving beyond weed control
- Ortega, Yvette; Pearson, Dean. 2009. Factors influencing plant invasiveness
- Hansen, Allison K.; Ortega, Yvette K.; Six, Diana L.. 2009. Comparison of ground beetle (Coleoptera: Carabidae) assemblages in Rocky Mountain savannas invaded and un-invaded by an exotic forb, spotted knapweed
- Ritter, Sharon; Jones, Greg; Watson, Alan; McCaughey, Ward; Harrington, Mick; Zwolak, Rafal; Foresman, Kerry; Crone, Elizabeth; Pearson, Dean; Ortega, Yvette; Loeffler, Dan. 2008. ECO-Report - Finding common ground: Montana Forest Restoration Committee
- Zwolak, Rafal; Foresman, Kerry; Crone, Elizabeth; Pearson, Dean; Ortega, Yvette. 2008. Are mice eating up all the pine seeds?
- Ortega, Yvette. 2007. Impacts of invasive plants on songbirds: Using song structure as an indicator of habitat quality
- Ritter, Sharon; Canton-Thompson, Janie; Ruggiero, Leonard F.; Jones, Greg; Sullivan, Janet; McCaughey, Ward; Ortega, Yvette; Christensen, Neal; Harrington, Mick; Page-Dumroese, Deborah. 2007. ECO-Report - Scientific independence: A key to credibility
- Ortega, Yvette Katina; McKelvey, Kevin Scot; Six, Diana Lee. 2006. Invasion of an exotic forb impacts reproductive success and site fidelity of a migratory songbird
- Sturdevant, Nancy; Kegley, Sandy; Ortega, Yvette; Pearson, Dean. 2006. Evaluation of establishment of Cyphocleonus achates and its potential impact on spotted knapweed
- Canton-Thompson, Janie; Saveland, Jim; Ritter, Sharon; Ortega, Yvette K; Pearson, Dean F.; Harrington, Mick; Sutherland, Elaine Kennedy; Cook, Clint; Jones, Greg. 2004. ECO-Report - Great issues, great diversions
- Canton-Thompson, Janie; Patton-Mallory, Marcia; Heald, Sue; Ritter, Sharon; Pfister, Robert D.; Pearson, Dean E.; Ortega, Yvette K.; Watson, Alan; Sutherland, Elaine Kennedy; Jones, Greg. 2003. ECO-Report - The case for research: How it makes a difference to managers
- Pearson, Dean E.; Ortega, Yvette K.; Ruggiero, Leonard F.. 2003. Trap-induced mass declines in small mammals: Mass as a population index
- Schwartz, M. K.; Mills, L. S.; Ortega, Y.; Ruggiero, L. F.; Allendorf, F. W.. 2003. Landscape location affects genetic variation of Canada lynx (Lynx canadensis)
- Ortega, Yvette K.; Capen, David E.. 2002. Roads as edges: Effects on birds in forested landscapes
- Canton-Thompson, Janie; Ritter, Sharon; Campbell, Dave; Schreck, Julie; Kolb, Peter; Thompson, Brooke; Zuuring, Hans; Watson, Alan; Ortega, Yvette; McKelvey, Kevin; Sutherland, Elaine Kennedy; Jones, Greg. 2002. ECO-Report - Fire recovery in the Bitterroot: "It’s a lot of work!"
- Pearson, Dean E.; Ortega, Yvette K.; McKelvey, Kevin S.; Ruggiero, Leonard F.. 2001. Small mammal communities and habitat selection in Northern Rocky Mountain bunchgrass: Implications for exotic plant invasions
- Pearson, Dean E.; Ortega, Yvette K.. 2001. An indirect dispersal pathway for spotted knapweed seeds via deer mice and great-horned owls
- Ortega, Yvette K.; Pearson, Dean E.. 2001. Occurrences of the western skink (Eumeces skiltonianus) in grasslands of western Montana
- Canton-Thompson, Janie; Jones, Greg; Smith, Jane Kapler; Rice, Peter; Harrington, Mick; Sutherland, Elaine Kennedy; McKelvey, Kevin; Ortega, Yvette; McCaughey, Ward; Pfister, Robert; Jones, Greg; Swanson, Larry; Wright, Vita. 2001. ECO-Report - One ranger's experience in summer 2000
- Ortega, Yvette K.; Capen, David E.. 1999. Effects of forest roads on habitat quality for Ovenbirds in a forested landscape
- McKelvey, Kevin S.; Ortega, Yvette K.; Koehler, Gary M.; Aubry, Keith B.; Brittell, J. David. 1999. Canada lynx habitat and topographic use patterns in north central Washington: A reanalysis [Chapter 10]
- Canton-Thompson, Janie; Smith, Jane Kapler; Jones, Greg; Brown, Perry J.; Arno, Stephen F.; Daniels, Orville L.; Burk, Dale A.; Hardy, Colin C.; Silvieus, Dave; Pflug, Kristi D.; Winhorst, Bruce; Thompson, Brooke; Ortega, Yvette K.; McKelvey, Kevin S.; Thompson, Tom; Pearson, Dean E.; Stewart, Cathy; Sullivan, Janet. 1999. ECO-Report - 1999 Symposium highlights five years of learning
Research Highlights
An herbicide solution to knapweed
Year: 2011
Station researchers evaluated the effects of a common herbicide treatment on grassland plants in western Montana to determine if and when suppression of spotted knapweed may relieve impacts of this notorious invader
Invasive Plant Erodes Bird Song Diversity via Food Chain Effects
Year: 2015
Although plant invaders are known for their negative effects on natural systems, the extent of these impacts is often unknown. Forest Service scientists studied how invasion of spotted knapweed (Centaurea stoebe) into grasslands of western Montana impacted native species from plants to insects to b...
The Bane of Weed Management: Secondary Invasions
Year: 2016
Weed management can result in unintentional secondary invasion: an increase in non-target exotics following efforts to suppress targeted invasive plants. Meta-analysis showed that management efforts strongly reduced target invader abundance overall; however, secondary invaders increased following co...
The tortoise and the hare: Can the slow native plant win?
Year: 2017
It has been suggested that exotic plants will be more successful than native plant species as a result of climate change. This is because exotics often exhibit stronger responses to disturbance, faster growth rates, and greater plasticity. In this study, we show that climate change can actually shif...
Invasiveness and Impact of 48 Exotic Plant Species in Native Grasslands
Year: 2015
This study quantified and ranked invasiveness and impact for 48 exotic plant species based on surveys over 20,000 square kilometers (12,427 square miles) of grasslands in western Montana. These data provide a valuable tool for managers to determine the relative impacts of invaders for prioritizing e...