Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Entire DC Network
Genetic Rescue Of Isolated Cutthroat Trout, Donovan Alexander Bell
Genetic Rescue Of Isolated Cutthroat Trout, Donovan Alexander Bell
Graduate Student Theses, Dissertations, & Professional Papers
Anthropogenic habitat destruction has isolated innumerable populations that now face increased extinction risk due to demographic and genetic factors. Although often the best strategy, restoring connectivity can be challenging or even harmful. Such is the case for westslope cutthroat trout (Oncorhynchus clarkii lewisi; WCT) in the Missouri River basin, which are limited to completely isolated populations. Nonnative species threaten WCT in connected watersheds and barrier removal could be detrimental. My dissertation examines trade-offs and strategies for the management of isolated WCT. I first examined how nonnative trout species and climate change influence the distribution of WCT using a multispecies, dynamic …
Biological Control: Effects Of Tyria Jacobaeae On The Population Dynamics Of Senecio Jacobaea In Northwest Montana, Kimberly Kay Crider
Biological Control: Effects Of Tyria Jacobaeae On The Population Dynamics Of Senecio Jacobaea In Northwest Montana, Kimberly Kay Crider
Graduate Student Theses, Dissertations, & Professional Papers
Biological control, using introduced, specialist insects is a common strategy for controlling plant invasions. However, the efficacy of biological control agents in controlling their host plants is rarely quantified population level. I quantified the impact of a specialist biological control agent, the cinnabar moth (Tyria jacobaeae) on its host plant, tansy ragwort (Senecio jacobaea) in northwest Montana. Cinnabar moth damage and its effects on important plant vital rates were tested with and without specialist herbivores. The presence of moth larvae corresponded to a reduction in population growth rates to less than one, compared to herbivore-free controls, indicating the potential for …
The Biogeography Of Ageratina Adenophora: A Mexican Trans-Global Invader, Heather Marie Evans
The Biogeography Of Ageratina Adenophora: A Mexican Trans-Global Invader, Heather Marie Evans
Graduate Student Theses, Dissertations, & Professional Papers
Evans, Heather, Master of Science, May 2010 The Biogeography of Ageratina adenophora: A Mexican Trans-Global Invader Co-Chairman: Dr. Jeffrey Gritzner Co-Chairman: Dr. Ragan Callaway Invasive plants are a global problem often resulting in negative impacts upon populations of native plants and the environments in which they grow. Invasive plants inhibit native species and take over areas where they have been introduced. These invasive species create ecological problems for wildlife foraging, as they often transform the vegetation of native habitats resulting in conditions unsuitable for grazing. In addition, invasive plant species pose problems for humans in the areas of health, economics, …
An Experimental Demographic Approach To Exotic Plant Success: Cynoglossum Officinale In Its Native And Introduced Ranges, Jennifer Lynn Williams
An Experimental Demographic Approach To Exotic Plant Success: Cynoglossum Officinale In Its Native And Introduced Ranges, Jennifer Lynn Williams
Graduate Student Theses, Dissertations, & Professional Papers
Invasive species often face novel abiotic and biotic environments with different selective regimes where they are introduced. How these changed conditions influence individual life-history traits, and what particular factors spur increases in population abundance in the introduced versus native range, are not well understood. I conducted parallel experiments in both the native and introduced ranges of a widespread plant invader in North America, houndstongue (Cynoglossum officinale). I combined these experimental results with demographic monitoring in each range, and population modeling, to explore how introduction has affected houndstongue demography and life-history evolution, and to determine the role of specialist …
Monitoring Program And Assessment Of Coyote Predation For Olympic Marmots, Julia Judyta Witczuk
Monitoring Program And Assessment Of Coyote Predation For Olympic Marmots, Julia Judyta Witczuk
Graduate Student Theses, Dissertations, & Professional Papers
Witczuk, Julia J. M.S., Summer2007 Wildlife Biology MONITORING PROGRAM AND ASSESSMENT OF COYOTE PREDATION FOR OLYMPIC MARMOTS Chairperson: L. Scott Mills The Olympic marmot (Marmota olympus) is an endemic species to the Olympic Peninsula, Washington State. Although nearly all of its range is enclosed within Olympic National Park, declines and local extirpations of the species have been documented. The most plausible driver of the decline appears to be an increase in predator pressure. My thesis had two main objectives. First, I investigated the role of non-native coyotes (Canis latrans) in causing marmot mortality. Through park-wide carnivore scat analysis I determined …
Predicting Spotted Knapweed (Centaurea Maculosa) Range Expansion Near Missoula Montana Using Localized Climate And Elevation Data, William Frank Preston Cumming
Predicting Spotted Knapweed (Centaurea Maculosa) Range Expansion Near Missoula Montana Using Localized Climate And Elevation Data, William Frank Preston Cumming
Graduate Student Theses, Dissertations, & Professional Papers
Since the 1920s spotted knapweed (Centaurea maculosa) has adapted to a variety of habitats, including pastureland, rangeland, hay land, open forests, road sides, and ditches. In 2003 this plant species dominated more than five million acres in Montana, half of the total infestation of noxious weeds in the state. This project demonstrates the utility of using downscaled Parameter-elevation Regressions on Independent Slopes Model (PRISM) data for predicting vegetation movement within a 2°×2° geographical area surrounding Missoula County, Montana. This localized climate change data was correlated against current knapweed range using validation data from the Volunteer for Wilderness Program at the …