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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Bureaucratic Response in an Era of Rapid Change: the Implementation of Strategic Habitat Conservation within the U.S. Fish and Wildlife Service

Hanna, Heather Lea 09 December 2016 (has links)
Can public organization managers respond to rapidly changing environmental conditions given that stability is a primary societal function of bureaucracies? If so, how might they successfully bring about change? Bennis (1966) states that examinations of organizational change fall into two categories: 1) those attempting to explain why organizations change and 2) those attempting to explain how organizations change. Those exploring why organizations change question the degree to which managers can serve as successful stimuli for transformation. This is true across public and private realms, but is particularly germane to public organizations, where managerial agency is restricted by accountability, civil service employee protections, and democratic norms. A Rational Adaptive philosophy of change suggests that managers can and do change organizations; however, with the exception of transformation in the face of budgetary and managerial crises, little evidence exists for manager-initiated, public organization change. Furthermore, prescriptions for how to bring about change are largely anecdotal and private-sector oriented. While Contingency Theory posits that no one-sizeits-all formula will suffice across all organization types and contexts, public administration scholars have proposed testable propositions regarding drivers of bureaucratic transformation. Using descriptive statistics, qualitative analysis, and logistic regression, this study examined one U.S. national agency’s attempt at transformational change to determine 1) the degree to which managers achieved success and 2) under what circumstances success was achieved. A theoretical typology for U.S. hierarchical, national agencies attempting internal policy change was proposed using the testable propositions, and a derivative model of change was tested to determine the types of manager-initiated efforts that yielded organizational change versus those that did not. Results suggest that, while transformational organizational change is challenging, managers of public organizations can create changes in employee attitudes and behavior in the absence of immediate crisis by communicating the vision for the change effectively and incorporating change-related routines in employees’ workplaces. Managerial support for the change may influence employee attitudes regarding the change and encourage support, while change-related incentives may promote behavior changes and adoption. Furthermore, adequate provision of change-related resources may be an important component in ensuring employees who desire to change can do so.
32

Arthropod Abundance and Diversity in Miscanthus x giganteus, Panicum virgatum, and Other Habitat Types in Southeastern Ohio

Snelick, Taylor L. 13 July 2018 (has links)
No description available.
33

Habitat Conservation Plan Implementation: Keeping Promises for Adaptive Management Within a "No Surprises" Policy

Smith, Bernice Loretta 09 December 2005 (has links)
Adaptive management is an approach to problem solving that acknowledges uncertainty. Adaptive management involves a systematic and rigorous process of learning from the outcomes of management actions, accommodating change and improving management. Plans, policies or management strategies influenced by new information and learning, are modified. This study examines the implementation of adaptive management for endangered and threatened species covered in Habitat Conservation Plans (HCP). Introduced in 1982 as an amendment to the Endangered Species Act (ESA), Habitat Conservation Plans are negotiated agreements that mitigate the incidental "take" (killing, harming) of endangered and threatened species during a development or resource extraction project. However, scholars found the scientific basis of approved HCPs to be inadequate and the efficacy of prescribed mitigation measures untested implying the need for adaptive management during implementation. This case study evaluation investigates HCP landowner compliance and progress within the parameters of the federal 1994 "No Surprises" policy. That policy limits landowner liability and responsibility for additional conservation action due to failed mitigation measures during HCP implementation. "No Surprises" assumes we can predict all the consequences of implementing a HCP. The policy seems to work against the objectives of adaptive management to improve scientific knowledge and modify action. The cases include the Central Cascades HCP implemented in the Central Cascades of Washington and the Orange Central Coastal County HCP implemented within a nature reserve in Orange County, California. The study assesses the strengths and weaknesses of adaptive management implementation for protecting endangered species and their habitat, and 2) recommends mid-course corrections for improving adaptive management before HCP maturity. / Ph. D.
34

Optimisation de la récolte de bois dans un contexte de protection de l'habitat du caribou forestier

Cyr, Guillaume 20 April 2018 (has links)
Un déclin mondial des populations de caribou forestier est présentement observé. Il devient impératif d’envisager des stratégies d’aménagement pour atténuer l’impact négatif de l’aménagement forestier sur le caribou. L’objectif principal de ce projet est donc de déterminer l’impact de différentes approches de spatialisation de la récolte dans un contexte d’optimisation de la récolte de matière ligneuse afin de préciser la relation entre la possibilité forestière et la qualité de l’habitat du caribou forestier. Plusieurs scénarios de récolte ont été simulés et évalués sur un horizon de 150 ans en tenant compte du régime de feu, d’un indice de perturbation du territoire, d’un indice de qualité d’habitat, du niveau de coupe du territoire et de l’importance du réseau routier. Les résultats indiquent que l’augmentation de la taille des compartiments de coupe et l’ajout de certaines contraintes spatiales permet d’augmenter la probabilité d’observation du caribou forestier et de réduire l’importance du réseau routier, mais produit également une diminution de la possibilité forestière.
35

Effects of freshwater discharges and habitat architecture on oyster reef community development and diversity

Unknown Date (has links)
Oyster reefs support diverse estuarine communities and food webs. Factors controlling oyster reef community development were studied on restored reefs in the St. Lucie Estuary. Freshwater discharges create stresses that cause oyster mortality, habitat loss and reduction in reef community diversity. Using structural equation modeling, it was demonstrated that salinity, turbidity, and chlorophyll-a gradients influence oysters and some reef invertebrate species, but did not support the predictions of the Intermediate Disturbance Hypothesis. In contrast, diversity and species richness were greatest at low stress sites. A field experiment showed that topographic relief and architectural complexity enhanced colonization and growth of reef-building species (e.g.oysters and mussels). The relief by complexity interaction had a higher order, synergistic effect on oyster abundance. When considered separately, increasing relief further enhanced dominant sessile taxa (cirripeds and ascideans) ; while, increasing complexity supported greater species richness and the abundance of cirripeds. / by Elizabeth A. Salewski. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
36

The ecology and conservation of the Adonis Blue (Polyommatus bellargus) and the Chalkhill Blue (Polyommatus coridon) butterflies in the UK

O'Connor, Rory Sean January 2014 (has links)
A combination of habitat loss, degradation and fragmentation are causing declines in butterfly species across Europe, with habitat specialists more vulnerable than generalists. The influence of climate change is serving to complicate matters, particularly at the edge of geographic ranges. Improving the quality of habitats is a key tool for the conservation of threatened species at both a local and landscape scale and this requires a thorough understanding of the ecology and habitat requirements of species. From this perspective this thesis examines and compares the ecology of two closely butterfly species, Polyommatus bellargus (the Adonis Blue) and Polyommatus coridon (the Chalkhill Blue) in southern England; calcareous grassland specialists, found in a highly fragmented ecosystem at the northern most edge of their geographic range. Chapter 2 explores whether there has been an expansion in the larval niche of P. bellargus due to a warming climate in recent decades, and finds no indication of change once concurrent local habitat change has been accounted for. Chapter 3 examines the role that differences in microhabitat requirements play in differentiating the larval niche of P. bellargus and P. coridon, showing P. coridon has broader microhabitat requirements. Chapter 4 experimentally examines the specificity of mutualistic interactions between the larvae of each butterfly species with the ants Myrmica sabuleti and Lasius niger. Chapter 5 uses microsatellites to explore the genetic structure of both P. bellargus and P. coridon, showing (as predicted) that P. coridon has a less fragmented population structure than P. bellargus, but both species have high levels of inbreeding.
37

Optimal bioeconomic management of changing marine resources

Moberg, Emily Alison January 2016 (has links)
Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2016. / Cataloged from PDF version of thesis. / Includes bibliographical references. / Marine populations are increasingly subjected to changing conditions whether through harvest or through broad-scale habitat change. Historically, few models have accounted for such trends over time, and even fewer have been used to study how trends affect optimal harvests. I developed and analyzed several models that explore, first, endogenous change caused by harvest and, second, exogenous change from factors (such as rising ocean temperatures) outside harvesters' control. In these models, I characterized the profit-or yield-maximizing strategy when harvesting damages habitat in a multispecies fishery, when harvest creates a selective pressure on dispersal, and when rising temperatures cause changes in vital rates. I explore this last case in both deterministic and stochastic environments, and also allow the harvester to learn about unknown parameters of the stock recruitment model while harvesting. I also develop an unambiguous definition of and describe a statistical test for a shift in a species' spatial distribution. My results demonstrate that optimal harvesting strategies in a changing environment differ in important ways from optimal strategies in a constant environment. / by Emily Alison Moberg. / Ph. D.
38

Identifying the Role of Policy Networks in the Implementation of Habitat Conservation Plans

January 2015 (has links)
abstract: Conflict over management of natural resources may intensify as population growth, development, and climate change stress natural systems. In this dissertation, the role of policy networks implementing Habitat Conservation Plans (HCPs) is examined. As explored here, policy networks are groups that come together to develop and implement terms of HCPs. HCPs are necessary for private landowners to receive Incidental Take Permits (ITPs) from the U.S. Fish and Wildlife Service (USFWS) if approved development activities may result in take of threatened or endangered species. ITPs may last up to 100 years or more and be issued to individual or multiple landowners to accomplish development and habitat conservation goals within a region. Theoretical factors in the implementation and policy network literatures relevant to successful implementation of environmental agreements are reviewed and used to examine HCP implementation. Phase I uses the USFWS Environmental Conservation Online System (ECOS) database to identify characteristics of policy networks formed to implement HCPs within the State of California, and how those networks changed since the creation of HCPs in 1982 by amendment of the 1973 Endangered Species Act. Phase II presents a single, complex, multiple-party HCP case selected from Phase I to examine the policy network formed, the role of actors in this network, and network successes and implementation barriers. This research builds upon the implementation literature by demonstrating that implementation occurs in stages, not all of which are sequential, and that how implementation processes are structured and executed has a direct impact on perceptions of success. It builds upon the policy network literature by demonstrating ways that participation by non-agency actors can enhance implementation; complex problems may better achieve conflicting goals by creating organizational structures made up of local, state, federal and non-governmental entities to better manage changing political, financial, and social conditions; if participants believe the transaction costs of maintaining a network outweigh the benefits, ongoing support may decline; what one perceives as success largely depends upon their role (or lack of a role) within the policy network; and conflict management processes perceived as fair and equitable significantly contribute to perceptions of policy effectiveness. / Dissertation/Thesis / Doctoral Dissertation Public Administration 2015
39

A flight of fancy in the Chorister Robin-Chat (Cossypha dichroa) : an isotopic standpoint

Wolmarans, Milena Helena Louise January 2015 (has links)
Forested areas have been cited for their highly diverse floral and faunal assemblages, which are currently under threat from anthropogenic activities that restrict their range and deplete the resources produced within these naturally fragmented patches. Historically, up to 67 percent of avifaunal species associated with well-treed areas have undergone localised extinctions, consequentially affecting biodiversity as a measure of species richness and ecosystem functionality. To date, more than 900 of the bird species affiliated with forests are under threat and despite the theory surrounding functional redundancy, the mass extinction that is currently underway poses considerable limitations on the ecological integrity of these biomes. In South Africa, indigenous forest (one of the rarest biomes), occurs predominantly in small isolated patches along the eastern escarpment. With mountainous terrain emphasised as ‘prominent hotspots of extinction’, the limited dispersal and habitat sensitivity of montane forest fauna renders these species more prone to localised extinctions. BirdLife International, the IUCN and SABAP2 all indicate reductions in the range and abundance of the Chorister Robin-Chat (Cossypha dichroa) - an endemic forest specialist that is reported to move seasonally between high-altitude forest patches where they breed in summer, and lowland coastal forests where they overwinter. Beyond diet, body morphology and vocalisations, much of the information available on the altitudinal movements of C. dichroa is based on secondary sources and the assumptions therein. This study aimed to investigate the potential utilisation of δ13C and δ15N stable isotopes in determining the dietary niche width and altitudinal movements of C. dichroa. Feathers obtained in forested patches of the Limpopo, KwaZulu-Natal and Eastern Cape provinces exhibited a wide trophic niche width and generalised diet. Strong regional separation is apparent in the isotopic signatures suggesting little movement between provinces. A comparison of 13C-isotopes showed minimal variation that point to a uniformity in the carbon-base utilised by C. dichroa across their range. The 15N-signatures obtained in Limpopo, however, revealed a distinct trophic segregation between the northern-most Chorister populations and their southern counterparts. No altitudinal movements were detected in the isotopic signatures of recaptured Choristers, but more research is needed to investigate the long-term accuracy of these results and the breeding potential of resident Choristers in lowland coastal forests; especially when considering the reduced range and abundance reported for this endemic species.
40

Carnivore Movement Ecology for Conservation Prioritization; synthetic, comparative, and machine learning approaches to model large carnivore movement in mixed-use landscapes

Schoen, Jay Michael January 2024 (has links)
The impacts of human activities on the natural world have accelerated rapidly in recent centuries and decades. Consequent loss and fragmentation of natural habitats is the greatest threat to short and long-term survival of the planet’s rich biodiversity. Large carnivores are particularly sensitive to these changes, as many species rely on expansive natural areas to maintain healthy, genetically diverse populations. As a result, this charismatic clade is a focal point of conservation attention, and is also frequently used as a conservation umbrella to conserve other species which share their broad range of habitats. While diminished, fragmented populations and geographic isolation can be detrimental to species longevity, habitat corridors which connect populations throughout a broader human-dominated landscape provide resistance and resilience to the effects of isolation by maintaining genetic connectivity between sub-populations. Accordingly, understanding how large carnivores move through natural and non-natural landscapes to connect with other populations is a key area of research in movement ecology and conservation biology. In this dissertation, collaborators and I implemented open-source synthetic, comparative, and machine learning approaches to model the movement of tigers and jaguars, two ecologically vital and connectivity-dependent carnivore species, in regions of their ranges which are largely shared with humans. For Chapters 1 and 2, focusing on tigers in central India, we synthesized five independently derived layers of landscape resistance to derive consensus among existing research (Chapter 1) and comparatively test different movement simulation techniques’ abilities to predict tiger occurrence data (Chapter 2). We found that existing research efforts on habitat quality and potential connectivity areas for tigers in central India were more aligned than independent results indicated. We also derived a geospatial layer for “consensus connectivity areas (CCAs)” – areas where existing research agreed on high potential movement for tigers – and detailed the extensive current and future anthropogenic pressures on these important areas. Additionally, we found that while outputs from several popular techniques for simulating wildlife movement can predict in situ tiger occurrences, a circuit theory-based method, Circuitscape, performed best overall in this landscape and was the most robust to both inputs and validation data used for the analysis. In Chapter 3, we analyzed a collection of jaguar telemetry data to understand how the environmental responses of jaguar movements vary depending on the behavioral state of the animal. We found that jaguars in a higher (i.e., exploratory) movement state were more likely to move through anthropogenic areas, low tree cover, and areas farther from high tree cover. As similar, less risk-averse behavior has been reported in other carnivores during larger scale movements such as dispersal, these exploratory movement patterns may be a proxy for dispersal movement tendencies and thus more applicable for connectivity planning for jaguars, particularly in mixed-use landscapes. Collectively, this research provides insight into the movement ecology of two threatened large carnivore species as well as multiple open-source methodologies for modeling movement that can be applied to other research questions and conservation objectives worldwide.

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