<p> Given the current mass extinction crisis and continued fragmentation of resources worldwide, the outlook is dire for global biodiversity. Rising global temperature, sea levels, and storm frequency all create environmental conditions that can drive change in species abundance and distribution across a landscape. Those species reliant upon a single type of habitat and resource for survival, termed "specialists", are particularly vulnerable to change due to their inability to utilize a variety of resources well. As a result, specialism is now considered one of the dominant factors determining extinction of species. In this dissertation I explore the effects of disturbance on habitat specialist birds in tidal marshes of the northeastern United States. This ecosystem is important due to the significant ecosystem services it provides to humans, and supports several specialist species including the saltmarsh sparrow (<i>Ammodramus caudacutus</i>). I examine this specialist bird community across scales of space, time, and ecological organization to A) evaluate the impacts of disturbance on tidal marsh communities and B) provide findings and management recommendations for long-term maintenance and conservation of coastal marsh ecosystems, specifically as they pertain to salt-marsh specialist birds. In Chapter 1 I introduce my study system and give background for the current conservation status of tidal marsh birds. In Chapter 2 I generate population trends in the five species particularly specialized to tidal marsh using a database of historical records, and explore potential drivers for population change through local and regional habitat disturbance. In Chapter 3 I expand upon patterns in Chapter 2 ad quantify life history strategy in marsh birds across a gradient of habitat specialization to explore how this metric explains species persistence in tidal marshes. In Chapter 4 I test several theoretical hypotheses from disturbance ecology empirically using traditional and novel community metrics. Finally, in Chapter 5 I respond to research needs identified in Chapter 4 to develop a method for quantification of high-marsh habitat using remote sensing methods. I hope the findings presented here contribute towards understanding of the mechanisms driving biodiversity patterns on our planet and help inform conservation priorities within the changing tidal marsh landscapes.</p>

Habitat loss is the leading cause of species extinction. Protecting and managing habitat quality is vital to an organism’s persistence, and essential to endangered species recovery. We conducted an investigation of habitat quality and potential impacts from climate change to piping plovers (Charadrius melodius) breeding on the barrier island ecosystem of New York, during 2003-2005. Our first step in this analysis was to examined the relationship between two common measures of habitat quality: density and productivity (Chapter 1). We used both central and limiting tendency data analysis to find that density significantly limited productivity across many spatial scales, especially broader scales. Our analysis of plover habitat quality (Chapter 2) focused on (1) identifying the spatial scaling of plovers to their environment; (2) determining the relative importance of four aspects of the environment (land cover, predation, management, and disturbance); and (3) determining the key environmental variables that influence productivity. We found that plover habitat selection occurred within a narrow range of spatial scales that was unique to each environmental variable. Further, we found that management and predation variables influenced population-level productivity relatively more than land cover and disturbance. Environmental variables with a significant positive influence on habitat quality were land management units, plover conservation educational signs, and symbolic string fencing erected around plover nesting areas. We found a significant negative relationship among density of people on ocean beaches, herring gull density, and land cover degradation. To quantify possible impact to plover habitat from future climate change (Chapter 3), we examined the extent of habitat change resulting from different estimates of sea-level rise (SLR) and storminess over the next 100 years. We found that the particular SLR estimate, habitat response, and storm type used to model climate changes influenced the amount of potential habitat available. Importantly, we observed synergy between SLR and storms resulting in the increasing impact of SLR and storms on plover habitat over the next 100 years. Finally, we found that coastal development contributed considerably to habitat loss when combined with climate changes. Our findings raise concerns regarding current plover recovery goals and management strategies. Density-dependent productivity may threaten the goal of a joint increase in both plover population and productivity. We advocate density monitoring and allocation of alternative nesting areas to provide the relief of possible high-density limitations. Based on our analysis of habitat selection and climate change threats, we call for a shift in management focus away from known breeding areas, towards ecosystem processes. Long-term conservation of piping plover habitat quality is more likely through protecting and promoting natural barrier island dynamics (i.e. overwash and migration) and minimizing human development on the barrier islands of New York State.

No description available.

<p> Understanding how to balance human well-being and ecological integrity is one of the fundamental challenges in conservation and natural resource management. As our human-footprint on ecosystems expands and deepens, we are increasingly realizing that human well-being is crucial to understanding social-ecological systems and managing them sustainably.</p><p> In my first chapter I add to this literature by extending a theoretical model to examine the effects of two biophysical stressors on a marine species. While this model was developed to understand how harvest and climate change may interact to affect species viability, the model instead emphasized the sensitivity of the results to assumptions about human behavior. This result adds to a small, but growing, body of literature that demonstrates the importance of considering resource-users&rsquo; dynamics when attempting to predict outcomes for biophysical systems.</p><p> Despite conceptual advances in linking human-wellbeing to biophysical dynamics, a major challenge exists in operationalizing these conceptual framings. In my second chapter I use the US West Coast commercial fisheries system as a case study and developed a novel network approach of linking the social system (i.e. fishing communities) to the ecological system (the fish). This approach made use of data collected by management, making it immediately operational for all managed fisheries in the US. Such a conceptual framework represents a major step forward for mapping and quantifying these linkages between social and natural systems. I add to this work by analyzing these resultant networks to show that the topological structure and modularity varied non-randomly, providing additional features that may be useful for mangers seeking to balance human well-being with sustainable populations of fish.</p><p> In my third chapter I analyzed patterns of participation across the US West Coast commercial fisheries before and after a major management change in a single fishery. Using individual- and fishing community-level analyses, using the framework described above, I show that the policy affected how fishermen shift their effort across fisheries at the individual level, but community level attributes remain unchanged. This work demonstrates how such social-ecological system level policy analysis may be conducted.</p><p> Overall this dissertation helps move us towards a set of tools managers can use to evaluate policy efficacy in commercial fisheries in the face of rapid environmental change while balancing ecological integrity and human well-being.</p>

This thesis attemps to examine the continuity and change in the physical character of Anatolian city which have crucial impacts on conservation of cultural values of town. From the mid-nineteenth century to the present time / decline of Ottoman Empire, establishment of Turkish Republic with new regime, wars in National Struggle, natural disasters, the policies of both central and local authorities, new regulations for urban planning and conservation are the reasons determined as major causes for the continuity and the change of historic urban character of towns. Sinop, which was one of Ottoman port city having commercial and military function, is representative of the towns in which the big changes are observed. Therefore, in this thesis Sinop is chosen as a case study. It is aimed to see the reasons and results of continuity and change in its physical character, how they take place in city and the values which heve been lost are analyzed.

<p> Climate change and over-use of natural resources impacts ecosystems worldwide. Understanding physical impacts from climate and natural resource use on biological processes at multiple scales of spatial and ecological organization is needed to make useful predictions under global change scenarios. Mountain aquatic ecosystems are of particular concern because they are sensitive to climate change, represent hot spots of biodiversity, and they integrate atmospheric, terrestrial and aquatic processes into biological responses. The objective of this dissertation is to quantify physical impacts and biological responses of climate and water use on mountain aquatic ecosystems in the Western United States. In Chapter 1, I developed a data set of ice break-up dates using remote sensing techniques for mountain lakes across the Sierra and Cascade Mountain Ranges coupled with downscaled climate data to quantify drivers of lake ice phenology. I developed a predictive linear mixed effects model and used and ensemble of 15 global climate models to project changes in lake ice break-up dates through the 21^st century. The results suggest that low snowpack and increased energy fluxes associated with elevated air temperatures drive earlier ice break-up dates. Projections of ice break-up show that ice break-up will be 61 &plusmn; 5 days if greenhouse gas emissions are not reduced. In Chapter 2, I analyzed specific ecological responses to earlier ice break-up dates in Castle Lake, California (a natural, sub-alpine lake). I predicted that consumer (Brook Trout; <i>Salvelinus fontinalis</i>) energetics and habitat use would be regulated by either climate driven water temperature or variation in food availability. The data suggest that earlier ice break-up results in a longer duration of surface water temperatures > 15 &deg;C, coupled with decreased and increased food production in the pelagic and littoral zones, respectively. Isotopic and telemetry data showed that consumer resources and habitat use were driven by water temperature and were independent of food availability. In early ice break-up years, consumers grew less because they were thermally excluded from productive littoral zones when water temperatures were warmer for longer periods of time relative to late ice break-up years. In Chapter 3, I demonstrate that decreased streamflow in mountain rivers can reduce abundance and size structure of food supply to drift foraging Rainbow Trout <i>(Onchorhynchus mykiss)</i>. In response to changes in streamflow and food availability, trout abandoned their energetically profitable drift foraging strategy and actively searched for prey. The shift in foraging behavior resulted in negative bioenergetic efficiencies in flow impaired sites. Taken collectively this research demonstrates that both predictable and unpredictable consequences of physical change drive biological responses across spatial gradients, ecosystem types, and levels of ecological organization.</p><p>

No description available.

<p>Very little protection has been afforded to wetlands1 and estuaries within the South African legislative framework.2 These ecosystems are extremely important and valuable to mankind, the flora and fauna.3 The continued destruction of wetlands and estuaries is the most heinous act of environmental vandalism on a worldwide scale today.4 Wetland and estuarine loss has been accelerated and extended by human activities such as mining,5 urbanisation,6 drainage, river diversion,7 groundwater abstraction as well as climate change.8 Time is running out for so many critically important sites and for the world at large.9 Without wetlands and estuaries the biosphere10 cannot continue to do its essential work.11 Despite, the importance of a range of resources and services12 which wetlands and estuaries provide, these have been taken for granted by humans.13 As a result hereof, the maintenance of wetlands and estuaries has received low priority in many countries.14 This is further precipitated by the lack of interest and ignorance which result in the conversion of wetlands and estuaries into man-made structures.15 Research has shown that the lack of information and the awareness of the importance of these ecosystems has the made the conservation legislation for these ecosystems a toothless dragon.16 People are becoming increasingly aware17 of the loss of wetlands and estuaries, once in abundance and now merely shadows of their former nature.18 To investigate this lack of protection, the starting point would be the global level.</p>

<p>Very little protection has been afforded to wetlands1 and estuaries within the South African legislative framework.2 These ecosystems are extremely important and valuable to mankind, the flora and fauna.3 The continued destruction of wetlands and estuaries is the most heinous act of environmental vandalism on a worldwide scale today.4 Wetland and estuarine loss has been accelerated and extended by human activities such as mining,5 urbanisation,6 drainage, river diversion,7 groundwater abstraction as well as climate change.8 Time is running out for so many critically important sites and for the world at large.9 Without wetlands and estuaries the biosphere10 cannot continue to do its essential work.11 Despite, the importance of a range of resources and services12 which wetlands and estuaries provide, these have been taken for granted by humans.13 As a result hereof, the maintenance of wetlands and estuaries has received low priority in many countries.14 This is further precipitated by the lack of interest and ignorance which result in the conversion of wetlands and estuaries into man-made structures.15 Research has shown that the lack of information and the awareness of the importance of these ecosystems has the made the conservation legislation for these ecosystems a toothless dragon.16 People are becoming increasingly aware17 of the loss of wetlands and estuaries, once in abundance and now merely shadows of their former nature.18 To investigate this lack of protection, the starting point would be the global level.</p>

No description available.