Chicago Botanic Garden

Plant Science — OUR SCIENTISTS

SkogenKrissa Skogen, Ph.D.

Conservation Scientist
Manager, Conservation and Land Management Internship Program

Ph.D., University of Connecticut, 2008 

Graduate Faculty Membership
Northwestern University, Plant Biology and Conservation


phone (847) 835-6919

 

Research Interests

  • Reproductive and pollination biology
  • Demography
  • Population genetics
  • Large-scale anthropogenic threats to biodiversity
  • Understanding the causes and consequences of plant population and species decline


Statement

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Because plants face a multitude of threats, using a combination of scientific methodologies is often necessary to identify the causes and consequences of population and species decline. A synthetic approach allows for a more complete understanding of how anthropogenic activities may negatively impact sensitive species — including endangered, threatened, and endemic plant species. My research combines a variety of different scientific approaches to answer broad-scale conservation questions to ultimately guide policy and management decisions. In particular, my research integrates data on population genetics, demography, reproductive biology, and threats imposed by anthropogenic activities, including nitrogen deposition and habitat fragmentation.
 
Long-Distance Pollinator Movement – Oenothera harringtonii

This project investigates pollination, reproduction, and gene flow in the Colorado Springs evening primrose (Oenothera harringtonii, Onagraceae), a species endemic to southeastern Colorado. The flowers of Oenothera harringtonii open soon after sunset and are pollinated primarily by hawkmoths. Hawkmoths can travel up to 20 miles in just one night, and may therefore contribute significantly to long-distance gene flow among populations. These moths feed on the nectar of Oenothera flowers, which they locate by the strong fragrance produced by the flowers. This species is found in an increasingly fragmented landscape; however, little is known of the impacts that fragmentation and light pollution may have on the community of pollinators upon which it relies for reproduction and long-term population persistence. Studying populations in both fragmented/developed and unfragmented areas will allow me to determine the extent to which habitat fragmentation and light pollution may be negatively impacting both hawkmoth populations as well as populations of Oenothera harringtonii. A combination of field, greenhouse, and molecular tools are being used to understand which pollinators visit flowers, to what they are attracted (floral scent, size, nectar sugar concentration, etc.), whether plants are successfully reproducing (demographic data, hand pollinations), and to examine patterns of gene flow (microsatellite markers).

Conservation and Restoration in Changing Environments – Colorado Plateau

Together with Drs. Jeremie Fant and Dan Larkin, I am investigating plant genetic, demographic, and community dynamics in intact and restored habitats designed to guide effective and efficient restoration in the western United States. This is a region with great need for research to help guide restoration practices and policies, as demonstrated by the Great Basin Native Plant Initiative and the Colorado Plateau Native Plant Initiative. These initiatives, comprising governmental, academic and private agencies and institutions, focus on developing an adequate supply of appropriate native plant materials to facilitate the enhancement, recovery, and/or restoration of landscapes throughout the region, as well as on developing scientifically rigorous methodologies that ensure successful establishment and persistence of restored native plant habitats.

In the summer of 2010, two teams of students will assess plant and pollinator communities and phenological changes over a six-week flowering period in and around Springdale, Utah, and Montrose, Colorado, working with the Bureau of Land Management and the National Park Service (Zion National Park) to provide a baseline data for use in future projects.

Understanding Causes and Consequences of Species Decline – Desmodium cuspidatum

My previous research on the perennial legume, Desmodium cuspidatum (large-bracted tick-trefoil, Fabaceae), explored whether nitrogen deposition (acid rain) may contribute to the decline of a nitrogen-fixing plant species. This species has experienced a dramatic decline in the northeastern portion of its range in the last 30 years, from approximately 28 populations in the mid-1970s to just nine populations as of 2007. However, populations elsewhere in the species range have not declined. Interestingly, the pattern of decline in Desmodium cuspidatum is consistent with the pattern of nitrogen deposition in the United States: the highest, for the longest period of time, in the northeast. Studies of demography and reproductive biology revealed that extremely low reproductive success and recruitment (birth) rates might be limiting population growth. Furthermore, patterns of genetic diversity suggest that current populations harbor high levels of genetic diversity but might be threatened in the future if gene flow is restricted among existing populations.


Graduate Students

Rebecca Barak (2011)

Emily Booth (2011)  Effects  of climate change on plant-pollinator relationships in Mirabilis multiflora and Oenothera caespitosa subspecies marginata at Zion National  Park, Utah, USA.

Melissa Gray (2011) Effects of community density on reproductive output.


Publications

Skogen, K., K. H. Holsinger, and Z. G. Cardon. In revision. Nitrogen deposition and the decline of a regionally threatened legume, Desmodium cuspidatum. Oecologia.

Skogen, K., L. Senack, and K. Holsinger. In revision. Dormancy, small seed size and low germination rates contribute to low recruitment in Desmodium cuspidatum (Fabaceae).  Journal of the Torrey Botanical Society.


Guest Lectures and Seminars

Does fragmentation negatively impact plant species pollinated by long-distance dispersers? Variation in floral advertisements, rewards and neutral genetic markers in Oenothera harringtonii. April 2010. The Field Museum, Chicago.

Evening primroses, pollinators and practicality. July 2008. NSF Research Experience for Undergraduates Seminar, Chicago Botanic Garden.
  
Declining Desmodium: Multiple approaches to solving a unique conservation problem. February 2008.
Biology Departmental Seminar, Central Connecticut State University, New Britain, Conn.

Using scientific data to inform plant conservation decisions. February 2008. Guest Lecturer, Biology 327, Vascular Plants. Instructor: T. Mione. Central Connecticut State University, New Britain, Conn.


Selected Published Abstracts

(Oral presentations unless otherwise noted; * indicates presenting author.)

Skogen, K*, R. Raguso, J. Fant, E. Hilpman*, S. Kelso, and Q. Roberts. 2010. Fragmented fragrances: habitat modification, population structure and reproductive ecology in a rare prairie endemic, Oenothera harringtonii. Botanical Society of America, Snowbird, Utah.

Skogen, K.* and K. Havens. 2008. Demand for botanists on federal lands: Partnerships between botanic gardens and land management agencies. Botanical Society of America, Vancouver, British Columbia.

Skogen, K.* 2007. Does atmospheric nitrogen deposition contribute to the decline of a native nitrogen-fixing species, Desmodium cuspidatum? Botanical Society of America, Chicago, Ill.

Skogen, K.* 2006. Atmospheric nitrogen deposition and the decline of a nitrogen-fixing plant species. Environmental Protection Agency Science to Achieve Results Conference, Washington, D.C. Poster presentation.

Skogen, K.* and K. Holsinger. 2006. Does size matter? Genetic diversity in declining and secure populations of Desmodium cuspidatum. Botanical Society of America, Chico, Calif.

Holsinger, K.*, and K. Skogen. 2005. Plant genetic consequences of pollinator declines. National Research Council Workshop on the Status of Pollinators in North America. National Academy of Sciences, Washington, D.C.

Skogen, K.* 2005. Demography and reproductive biology of threatened populations of Desmodium cuspidatum (Fabaceae). Botanical Society of America, Austin, Tex.

Skogen, K.* 2003. Exploring causes of decline in the large-bracted tick-trefoil, Desmodium cuspidatum, (Fabaceae). 2003 National Science Foundation/New England Wildflower Society Fellowship in Conservation Biology Symposium, New England Wildflower Society, Framingham, Mass. Oral and poster presentations.

Skogen, K.* 2003. Exploring causes of decline in rare plant species. Northeast Ecology and Evolution Conference, Rutgers University, New Brunswick, N.J.