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- All Subjects: Biodiversity conservation
- Creators: Hall, Sharon
- Creators: Nyaupane, Gyan
Description
It’s no secret that wetlands have dramatically declined in the arid and semiarid American West, yet the small number of wetlands that persist provide vital ecosystem services. Ciénega is a term that refers to a freshwater arid-land wetland. Today, even in areas where ciénegas are prominent they occupy less than 0.1% of the landscape. This investigation assesses the distribution of vascular plant species within and among ciénegas and address linkages between environmental factors and wetland plant communities. Specifically, I ask: 1) What is the range of variability among ciénegas, with respect to wetland area, soil organic matter, plant species richness, and species composition? 2) How is plant species richness influenced locally by soil moisture, soil salinity, and canopy cover, and regionally by elevation, flow gradient (percent slope), and temporally by season? And 3) Within ciénegas, how do soil moisture, soil salinity, and canopy cover influence plant species community composition? To answer these questions I measured environmental variables and quantified vegetation at six cienegas within the Santa Cruz Watershed in southern Arizona over one spring and two post-monsoon periods. Ciénegas are highly variable with respect to wetland area, soil organic matter, plant species richness, and species composition. Therefore, it is important to conserve the ciénega landscape as opposed to conserving a single ciénega. Plant species richness is influenced negatively by soil moisture, positively by soil salinity, elevation, and flow gradient (percent slope), and is greater during the post-monsoon season. Despite concerns about woody plant encroachment reducing biodiversity, my investigation suggests canopy cover has no significant influence on ciénega species richness. Plant species community composition is structured by water availability at all ciénegas, which is consistent with the key role water availability plays in arid and semiarid regions. Effects of canopy and salinity structuring community composition are site specific. My investigation has laid the groundwork for ciénega conservation by providing baseline information of the ecology of these unique and threatened systems. The high variability of ciénega wetlands and the rare species they harbor combined with the numerous threats against them and their isolated occurrences makes these vanishing communities high priority for conservation.
ContributorsWolkis, Dustin (Author) / Stromberg, Juliet C. (Thesis advisor) / Hall, Sharon (Committee member) / Salywon, Andrew (Committee member) / Makings, Elizabeth (Committee member) / Arizona State University (Publisher)
Created2016
Description
Balancing conservation goals and needs of local residents is always challenging. While some believe protected areas are a safe paradise for wildlife, others suggest that it is shortsighted to ignore the social and economic challenges faced by people who live adjacent to protected areas when addressing conservation objectives. This dissertation explores the link between biodiversity conservation and environmental education programs (EEPs) administered to residents of buffer zones adjacent to three protected areas in the Terai Arc Landscape, Nepal. Using surveys and interviews, this study examined 1) the influence of EEPs on attitudes of local people toward biodiversity conservation; 2) the influence of EEPs on conservation behavior; 3) the responses toward biodiversity conservation of local people residing in buffer zones who have received different levels of EEPs; and 4) the effect of EEPs on wildlife populations within adjacent protected areas. Local people who had participated in EEPs and attended school were more likely to express a positive attitude toward conservation goals than participants who had not participated in EEPs or had the opportunity to attend school. Participation in EEPs and level of education favored expressed behavior toward conservation goals, such as making contributions for conservation or supporting anti-poaching patrols. However, EEP participants and non-participants were equally likely to engage in activities that were at odds with positive conservation behavior, such as collecting fuel wood or killing wildlife to protect their farm or feed their families. A direct comparison of EEPs given by schools versus non-government organizations showed that EEPs were largely ineffective in promoting positive conservation attitudes and behaviors. Despite heavy poaching of charismatic species such as the greater one-horned rhinoceros or tiger over past decades, Nepal recently celebrated ‘zero poaching years’ in 2011 and 2013, largely due to increased anti-poaching enforcement. The relationship between EEPs and the decline in poaching is unclear, although local officials all claimed that EEPs played an important role. These results indicate that current administration of EEPs in Terai buffer zone communities is inadequate, while also providing evidence that properly administrated EEPs may become a valuable investment for these protected areas to achieve long-term success.
ContributorsShrestha, Samridhi (Author) / Smith, Andrew T. (Thesis advisor) / Minteer, Ben (Committee member) / Pearson, David (Committee member) / Nyaupane, Gyan (Committee member) / Budruk, Megha (Committee member) / Arizona State University (Publisher)
Created2015