Matching Items (2)
Description
Amsonia kearneyana is an endangered herbaceous plant endemic to a small area of the Baboquivari Mountains in southern Arizona. It exists in two distinct habitat types: 1) along the banks of a lower elevation ephemeral stream in a xeroriparian community, and 2) a higher elevation Madrean oak woodland on steep mountain slopes. Half of the largest known montane population (Upper Brown Canyon) was burned in a large fire in 2009 raising questions of the species capacity to recover after fire. This research sought to understand how the effects of fire will impact A. kearneyana's ability to recruit and survive in the burned versus unburned areas and in the montane versus xeroriparian habitat.
I compared population size, abiotic habitat characteristics, leaf traits, plant size, and reproductive output for plants in each habitat area for three years. Plants in the more shaded unburned montane area, the most populated population, presented with the most clonal establishment but produced the least amount of seeds per plant. The unshaded burned area produced more seeds per plant than in the unburned area. Lower Brown Canyon, the xeroriparian area, had the fewest plants, but produced the most seeds per plant while experiencing higher soil temperature, soil moisture, photosynthetically active radiation, and canopy cover than the montane plants. This could indicate conditions in Lower Brown Canyon are more favorable for seed production.
Despite ample seed production, recruitment is rare in wild plants. This study establishes germination requirements testing soil type, seed burial depth, temperature regimes, and shade treatments. Trials indicate that A. kearneyana can germinate and grow in varied light levels, and that soil type and seed burial depth are better predictors of growth than the degree of shade.
Finally, this study examined the law, regulation, policy, and physiological risks and benefits of a new management strategy and suggests that "conservation by dissemination" is appropriate for A. kearneyana. Conservation by dissemination is the idea that a protected plant species can be conserved by allowing and promoting the propagation and sale of plants in the commercial market with contingent collection of data on the fate of the sold individuals.
I compared population size, abiotic habitat characteristics, leaf traits, plant size, and reproductive output for plants in each habitat area for three years. Plants in the more shaded unburned montane area, the most populated population, presented with the most clonal establishment but produced the least amount of seeds per plant. The unshaded burned area produced more seeds per plant than in the unburned area. Lower Brown Canyon, the xeroriparian area, had the fewest plants, but produced the most seeds per plant while experiencing higher soil temperature, soil moisture, photosynthetically active radiation, and canopy cover than the montane plants. This could indicate conditions in Lower Brown Canyon are more favorable for seed production.
Despite ample seed production, recruitment is rare in wild plants. This study establishes germination requirements testing soil type, seed burial depth, temperature regimes, and shade treatments. Trials indicate that A. kearneyana can germinate and grow in varied light levels, and that soil type and seed burial depth are better predictors of growth than the degree of shade.
Finally, this study examined the law, regulation, policy, and physiological risks and benefits of a new management strategy and suggests that "conservation by dissemination" is appropriate for A. kearneyana. Conservation by dissemination is the idea that a protected plant species can be conserved by allowing and promoting the propagation and sale of plants in the commercial market with contingent collection of data on the fate of the sold individuals.
ContributorsYost, Tyna (Author) / Stromberg, Juliet (Thesis advisor) / McCue, Kimberlie (Committee member) / Bradshaw-Schulz, Karen (Committee member) / Arizona State University (Publisher)
Created2015
Description
The National Wilderness Preservation System (NWPS) is a collection of more than 800 areas designated as wilderness under the Wilderness Act of 1964. The Act defines wilderness as an “area where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain.” Wilderness lands are supposed to be pristine examples of nature where the overseeing agency has not allowed any post-designation development. The language of the act describes land designated as wilderness as “untrammeled” by people, discounting thousands of years of human influence. It also discounts the potential effect of surrounding lands and visitors on the wilderness. The management of these lands falls to all four federal land management agencies, and they each had – and still have – their own organizational perspectives on the Wilderness Act and their agency’s role in its implementation. Although the Act provided criteria for designating and managing wilderness, concrete guidance is lacking. This ambiguity has allowed a rift to emerge between those who believe that wilderness should be actively managed and those who believe that wilderness should be preserved and left alone as much as possible. The diversity of views and agency approaches have created administrative divides between wilderness lands and other land types. In parallel, the introduction of subsequent environmental laws have placed additional legal boundaries on the land, creating parcels next to and within wilderness that are subject to different uses and requirements. This study, which marshals dozens of expert interviews and explores a series of wilderness cases across the United States, focuses on several unanticipated challenges of stewarding the NWPS in the 21st Century. These include: the impacts of public land parceling due to legal obligations; how statuary ossification affects current interpretations of the various laws bearing on wilderness lands; and ultimately how land managers and agencies – who are looking toward a future of increased anthropogenic impacts on wildlife biodiversity and endangered/threatened species on wilderness lands – approach these challenges.
ContributorsFacemire, Challie Renee (Author) / Minteer, Ben A (Thesis advisor) / Ellison, Karin (Thesis advisor) / Bradshaw, Karen (Committee member) / Hahn, Beth (Committee member) / Budruk, Megha (Committee member) / Arizona State University (Publisher)
Created2022