Succession, herbicides, forage nutrition and elk body condition at Mount St. Helens, Washington
Concerns have been voiced over recent reductions in forest cutting, herbicide spraying, and past heavy grazing on nutritional resources for elk (Cervus elaphus) and their body condition in the Pacific Northwest. I evaluated the effects of herbicides and herbivory on elk forage in a paired, retrospective vegetation sampling design for early seral (<13yrs) forests around Mount St. Helens (MSH), Washington. Common herbicide regimes reduced elk forage for <3 years after stand initiation and shortened the period of availability of the most nutritious forages prior to forest canopy closure. Herbicide-treated early seral stands provided higher nutritional resources for elk than mid and late-seral stands. Herbivory reduced biomass, primarily of highly palatable shrub species due to reductions in plant height rather than density. I related elk body fat derived from organs collected from hunter-harvested lactating elk in fall 2011 at MSH (n=55) to the habitat surrounding kill locations. Probability of an elk being pregnant was related to body fat. Lactating females were not thinner than non-lactating female elk, and barren non-lactating individuals had the poorest body condition. The most supported model predicting body fat of lactating elk included harvest date, elevation, and elk density.
Awards:
Queen Elizabeth II Graduate Scholarship (2011)
Alberta Graduate Student Scholarship (2011)
Publications and Reports:
AB Geary. (2012) Mount St. Helen’s Elk Habitat Study. Rocky Mountain Elk Foundation Washington Tracks Newsletter, Volume 7 Spring/Summer 2012
AB Geary, JG Cook, RC Cook, SC McCorquodale, PJ Miller, and EH Merrill. (2012) Habitat Selection and Nutritional Condition of elk at Mount St. Helens: Interim Report. Spring 2012. Progress Report Written for Washington Department of Fish and Wildlife, (10 pages)
AB Geary and EH Merrill. (2011) Habitat Selection and Nutritional Condition of elk at Mount St. Helens: Interim Report. Winter 2011. Progress Report Written for Washington Department of Fish and Wildlife, (12 pages)
AB Geary and EH Merrill (2010) Habitat Selection and Nutritional Condition of elk at Mount St. Helens: Interim Report. Fall 2010 Progress Report Written for Washington Department of Fish and Wildlife, 2010. (9 pages)
Presentations and media:
AB Geary, JG Cook, RC Cook, L Irwin, and EH Merrill. (2011) Testing the Interaction of Ungulate Herbivory and Herbicides on Vegetative Succession. National Council for Air and Stream Improvement, Inc. (NCASI) West Coast Regional Meeting for Forest Management Sessions, Vancouver, Washington.
AB Geary, JG Cook, and EH Merrill. (2011) Herbicide and herbivory study: understanding the true impacts of herbicide use vs. browse on forage quality and elk populations.
Weyerhaeuser Annual Foresters Meeting, Vancouver Washington. The Research and Recovery of Elk at Mount St. Helens. (2011) Oregon Field Guide, Oregon Public Broadcasting Television. Aired September 2011.
AB Geary. (2010) Continuing Elk Research at Mount St. Helens. United States Forest Service Science Pulse Symposium, Mount St. Helens, Washington.
Funders:
Am. Forest Resource Council, National Council of Air and Stream Improvement,
National Science and Engineering Council of Canada, OR Forest Industries Council,
University of Alberta,
WA Forest Protection Association,
WA State Pesticide Commission,
Weyerhaeuser Company ,
Wilbur-Ellis & Dow Chemical.
Cooperators:
Drew’s Grocery,
U.S. Forest Service,
WA Department of Natural Resources,
WA Department Fish and Wildlife