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- Genre: Masters Thesis
Description
Since its inception in 1973, the Endangered Species Act has been met with both praise and criticism. More than 40 years later, the Act is still polarizing, with proponents applauding its power to protect species and critics arguing against its perceived ineffectiveness and potential mismanagement. Recovery plans, which were required by the 1988 amendments to the Act, play an important role in organizing efforts to protect and recover species under the Act. In 1999, in an effort to evaluate the process, the Society for Conservation Biology commissioned an independent review of endangered species recovery planning. From these findings, the SCB made key recommendations for how management agencies could improve the recovery planning process, after which the Fish and Wildlife Service and the National Marine Fisheries Service redrafted their recovery planning guidelines. One important recommendation called for recovery plans to make threats a primary focus, including organizing and prioritizing recovery tasks for threat abatement. Here, I seek to determine the extent to which SCB recommendations were incorporated into these new guidelines, and if, in turn, the recommendations regarding threats manifested in recovery plans written under the new guidelines. I found that the guidelines successfully incorporated most SCB recommendations, except those that addressed monitoring. As a result, recent recovery plans have improved in their treatment of threats, but still fail to adequately incorporate threat monitoring. This failure suggests that developing clear guidelines for monitoring should be an important priority in future ESA recovery planning.
ContributorsTroyer, Caitlin (Author) / Gerber, Leah (Thesis advisor) / Minteer, Ben (Committee member) / Guston, David (Committee member) / Arizona State University (Publisher)
Created2014
Description
Aboveground net primary production (ANPP) and belowground net primary production (BNPP) may not be influenced equally by the same factors in arid grasslands. Precipitation is known to affect ANPP and BNPP, while soil fauna such as nematodes affect the BNPP through herbivory and predation. This study on black grama grass (Bouteloua eriopoda) in the Chihuahuan Desert investigates the effects of precipitation and nematode presence or absence on net primary production (NPP) as well as the partitioning between the aboveground and belowground components, in this case, the fraction of total net primary production occurring belowground (fBNPP). I used a factorial experiment to investigate the effects of both precipitation and nematode presence on the components of NPP. I used rainout shelters and an irrigation system to alter precipitation totals, while I used defaunated and re-inoculated soil for the nematode treatments. Precipitation treatment and seasonal soil moisture had no effect on the BNPP and a nonsignificant positive effect on the ANPP. The fBNPP decreased with increasing precipitation and seasonal soil moisture, though without a significant effect. No predator nematodes were found in any of the microcosms at the end of the experiment, though other functional groups of nematodes, including herbivores, were found in the microcosms. Total nematode numbers did not vary significantly between nematode treatments, indicating that the inoculation process did not last for the whole experiment or that nematodes had little plant material to eat and resulted in low population density. Nematode presence did not affect the BNPP, ANPP, or the fBNPP. There were no significant interactions between precipitation and nematode treatment. The results are inconclusive, possibly as a result of ecosystem trends during an unusually high precipitation year, as well as the very low NPP values in the experiment that correlated with low nematode community numbers.
ContributorsWiedenfeld, Amy (Author) / Sala, Osvaldo (Thesis advisor) / Gerber, Leah (Committee member) / Hall, Sharon (Committee member) / Arizona State University (Publisher)
Created2018
Description
Development throughout the course of history has traditionally resulted in the demise of biodiversity. As humans strive to develop their daily livelihoods, it is often at the expense of nearby wildlife and the environment. Conservation non-governmental organizations (NGOs), among other actors in the global agenda, have blossomed in the past century with the realization that there is an immediate need for conservation action. Unlike government agencies, conservation NGOs have an independent, potentially more objective outlook on procedures and policies that would benefit certain regions or certain species the most. They often have national and international government support, in addition to the credibility and influencing power to sway policy decisions and participate in international agendas. The key to their success lies in the ability to balance conservation efforts with socioeconomic development efforts. One cannot occur without the other, but they must work in coordination. This study looks at the example of African Great Apes. Eight ape-focused NGOs and three unique case studies will be examined in order to describe the impact that NGOs have. Most of these NGOs have been able to build the capacity from an initial conservation agenda, to incorporating socioeconomic factors that benefit the development of local communities in addition to the apes and habitat they set out to influence. This being the case, initiatives by conservation NGOs could be the key to a sustainable future in which humans and biodiversity coexist harmoniously.
ContributorsPrickett, Laura (Author) / Parmentier, Mary Jane (Thesis advisor) / Zachary, Gregg (Committee member) / Gerber, Leah (Committee member) / Arizona State University (Publisher)
Created2019
Description
Consumption of seafood poses a substantial threat to global biodiversity. Chemical contamination found in both wild-caught and farmed seafood also presents significant health risks to consumers. Flame retardants, used in textiles, upholstery, plastics, and other products to reduce risk of fire-related injury, are of particular concern as they are commonly found in the marine environment and permeate the tissues of fish that are sold for consumption via multiple pathways. The widespread issue of fishery collapse could be alleviated by demonstrating to stakeholders that many unsustainable fish stocks are also unhealthy and mutually disadvantageous for both human consumers and the environment. To thoroughly investigate the confounding factors and contradictory signals enmeshed in the relationship between ecologically sustainable fisheries and flame retardant contamination, I examined the biological characteristics of regional fish stocks which drive both contamination and perceived sustainability. I found that the biological and spatial aspects of commonly consumed aquatic and marine species best predict contamination when compared with various indices of sustainability. My results confirm that knowledge of flame retardant toxicity will become increasingly more important to consumers because a high percentage of global populations rely on coastal seafood for subsistence, and although dispersal of chemical contamination is still a poorly understood phenomenon, fish harvested closer to land are likely to contain higher concentrations of potentially harmful chemicals. Because some of the same biological traits which facilitate the uptake of chemicals also contribute to how a species responds to fishing pressures, concern for private health increases public consideration for the conservation of species at risk.
ContributorsNoziglia, Andrea (Author) / Gerber, Leah (Thesis advisor) / Abbott, Joshua (Committee member) / Polidoro, Beth (Committee member) / Arizona State University (Publisher)
Created2015
Description
Limited funding hinders endangered species recovery. Thus, decision makers need to strategically allocate resources to save the most species. Decision science provides guidance on efficient prioritization of conservation actions. However, endangered species recovery cost estimates are incomplete, so decision makers need to understand the implications of different cost estimation approaches. To test how different ways of estimating the expected costs of recovery action influence suggested recovery priorities, I used three different cost estimation scenarios for prioritizing recovery effort for 29 endangered species in Arizona. My scenarios explored “remaining” costs, calculated by subtracting historical spending from recovery plan cost estimates, “average” costs which substituted the average cost for actions in recovery plans, and “micro” and “macro” overlaps accounting for efficiency of costs due to implementing shared recovery actions for species with overlapping ranges. These different methods of estimating costs resulted in different numbers of recovery plans funded. At a representative budget, the macro overlap scenario recommended funding for 97% of plans as compared to 93% of plans under the baseline cost scenario. In contrast, the micro overlap (59%), the average (28%), and remaining (24%) cost estimation approaches all resulted in less plans recommended for funding than the baseline. There were also differences in how individual plans were ranked across the scenarios and variation in species chosen for funding. The order of recovery plans was similar between the baseline and the remaining scenario (WS = 0.833), and the baseline and the average scenario (WS=0.811). The similarity metric is based on the identity of species ranked equally. In contrast, there was less similarity in plan ranking between the baseline, the macro (WS=0.777), and micro (WS=0.442) overlap scenarios. A group of 4 plans remained within the top priority ranks, 5 plans were ranked as high priority for all scenarios except the remaining cost scenario, and 5 plans were consistently ranked as low priority. My results show how cost estimation approaches influence species priority rankings and can be used to help decision makers determine implications when they are exploring options for prioritization.
ContributorsSansonetti, Alice Maria (Author) / Gerber, Leah (Thesis advisor) / Iacona, Gwen (Thesis advisor) / Maas, Amy (Committee member) / Arizona State University (Publisher)
Created2023
Description
Food production and consumption directly impacts the environment and human health. Protein in particular has significant cultural and health implications, and how people make decisions about what type of protein they eat has not been studied directly. Many decision tools exist to offer recommendations for seafood, but neglect livestock or plant protein. This study attempts to address these shortcomings in food decision science and tools by asking the questions: 1) What qualities of a dietary protein-based decision tool make it effective? 2) What do people consider when making decisions about what type of protein to consume? Using literature review, meta-analysis, and surveys, this study attempts to determine how the knowledge gained from answering these questions can be used to develop an electronic tool to engage consumers in making sustainable and healthy decisions about protein consumption. The data show that, given environmental and health information about the protein types, people in the sample of farmers market shoppers are more likely to purchase wild salmon and organically grown soybeans, and less likely to purchase grain-fed beef. However, the order of preference among the six types of protein did not change. Additional results suggest that there is a disconnect between consumers and sources of dietary protein, indicating a need for improved education. Inconsistency in labeling and information regarding protein types is a large source of confusion for consumers who participated in the survey, highlighting the need for transparency. Results of this study suggest that decisions tools may help improve decision making, but new ways of using them need to be considered to achieve this.
ContributorsGeren, Sarah (Author) / Gerber, Leah (Thesis advisor) / Minteer, Ben (Committee member) / Wentz, Elizabeth (Committee member) / Arvai, Joseph (Committee member) / Arizona State University (Publisher)
Created2015
Description
Globally, land use change is the primary driver of biodiversity loss (IPBES, 2019). Land use change due to agricultural expansion is driving bird species to the brink of extinction in the Peruvian Amazon rainforest. Agriculture is one of the primary threats to bird species in the region, and agroforestry is being pursued in some communities as a potential solution to reduce agriculture's impacts on species, as agroforestry provides improved habitat for wildlife while also enabling livelihoods for people. Understanding how anthropogenic land use choices affect imperiled species is an important prerequisite for conservation policy and practice in the region. In this thesis, I develop a spatial model for quantifying expected threat abatement from shifting agricultural land use choices towards agroforestry. I used this model explored how agricultural land use impacts imperiled bird species in the Peruvian Amazon. My approach builds on the species threat abatement and restoration (STAR) metric to make the expected consequences of reducing agricultural threats spatially explicit. I then analyzed results of applying the metric to alternative scenarios with and without agroforestry conversion. I found that agroforestry could result in up to 18.68% reduction in mean bird projected population decline. I found that converting all terrestrial agriculture in the Peruvian Amazon to agroforestry could produce a benefit of up to 83% to imperiled birds in the region in terms of improvement in Red List status. This use of the STAR metric to model alternative scenarios presents a novel usage for the STAR metric and a promising approach to understand how to address terrestrial biodiversity challenges efficiently and effectively.
ContributorsPoe, Katherine (Author) / Iacona, Gwen (Thesis advisor) / Gerber, Leah (Thesis advisor) / Mair, Louise (Committee member) / Arizona State University (Publisher)
Created2023