Low species diversity in the Arctic promotes strong food-web linkages, as changes in abundance of one species may influence many others. Using harvest records, I determined Arctic fox populations are declining in their southern distributional range due to shallower snow potentially limiting density of lemmings, their primary prey, which live and breed beneath snow. Additionally, warm fall and spring temperatures are shortening access to alternative prey, seals on sea ice. Arctic foxes also influence other species through non-trophic interactions, as lemming winter nests were found on 70% of fox dens examined. I determined warmer subnivean temperatures promoted by accumulation of thick snow leeward of tall vegetation on dens attracted lemmings to these dens. Furthermore, lemming reproduction was higher dens compared to traditional lemming habitat. This research highlights the impact of climatic variables on Arctic predator-prey interactions and the importance of understanding impacts of trophic and non-trophic interactions on species demographics. / February 2017

Hydropower is often termed "green energy" and proffered as an alternative to polluting coal-generated electricity for burgeoning cities and energy-insecure rural areas. India is the third largest coal producer in the world; it is projected to be the largest coal consumer by 2050. In the Himalayan state of Uttarakhand, India, over 450 hydroelectric power schemes are proposed or are under development. Hydropower projects ranging from micro hydro (run-of-the-river systems with generating capacity up to 100 kW) to large reservoirs (storage systems up to 2000 MW) such as the Tehri Dam are in various stages of planning, construction or implementation. Run-of-the-river hydropower projects are being developed in Uttarakhand in order to avoid some of the costs to local communities created by large dams. Stakeholders in this rapid hydropower expansion include multiple actors with often diverging sets of interests. The resulting governance challenges are centered on tradeoffs between local electricity and revenue from the sale of hydropower, on the one hand, and the impacts on small-scale irrigation systems, riparian-corridor ecosystem services, and other natural resource-based livelihoods, on the other. We focus on the Bhilangana river basin, where water dependent livelihoods differentiated by gender include farming, fishing, livestock rearing and fodder collection. We examine the contradictions inherent in hydropower governance based on the interests of local residents and other stakeholders including hydropower developers, urban and other regional electricity users, and state-level policymakers. We use a social justice approach applied to hydropower projects to examine some of the negative impacts, especially by location and gender, of these projects on local communities and then identify strategies that can safeguard or enhance livelihoods of women, youth, and men in areas with hydropower projects, while also maintaining critical ecosystem services. By assessing the Bhilangana basin case, we also offer hydropower-livelihoods-irrigation nexus lessons for headwater regions across the Himalayas and globally.

In an ever more urban world, the role of green spaces in cities is increasingly highlighted for their capacity to provide ecosystem services for human well-being. Yet, the value of urban green spaces is still widely overlooked in urban policy and planning. This dissertation examines the evidence base for the multi-functionality and values of urban green spaces, in the context of decision support and for priority setting in urban policy and governance. First, the multi-functional character of urban green spaces and the many benefits they provide to humans through the delivery of ecosystem services is studied through a literature review. Secondly, the pluralism of values is examined through case studies from urban green spaces in Barcelona, Spain. Within these case studies, value perceptions, value emergence and value dimensions are scrutinized by combining different methods, including remote sensing, participatory observations, interviews, surveys, statistical analysis and geographical information systems. Finally, pathways for an integrated valuation of ecosystem services in urban planning are explored through a review of state-of-the-art knowledge on multi-criteria decision analysis applied in relation to ecosystem services. The dissertation shows the multi-functional character of urban green spaces and outlines their specific importance for the provision of cultural ecosystem services. It contributes to operationalize the perspective of value pluralism in the assessment of ecosystem services from urban green spaces. It is noted that the perception of diverging values is mainly determined by the characteristics of the ‘valuator’, the socio-institutional context, as well as different valuation languages through which values are assessed. The perspective of value pluralism endorsed in this thesis, underlines the need for an integrated valuation of ecosystem services to inform decision-making and governance. The thesis examines the potential of multi-criteria decision analysis as a tool to facilitate such integrated valuation of ecosystem services, in the context of urban planning. By putting forward the value of ecosystem services for humans, the thesis intents to provide a cornerstone for policies towards more sustainable and resilient cities that recognize the interconnection and dependency of cities on healthy ecosystems worldwide.

Many of the benefits that are generated by the natural environment are external to normal market transactions and are consequently undervalued and under-provisioned even though they substantially contribute to human welfare. One approach to valuing certain environmental goods and services is through a regression technique known as the property hedonic model. This model considers a property as a bundle of attributes where the total price of the property is decomposed into marginal, implicit prices for property-specific attributes, the context or neighborhood in which a property resides and access to environmental amenities. The goal of this dissertation research is to estimate the value of proximity to the environmental amenities of parks and open spaces using a property hedonic model for the City of Baltimore and suburban areas of Baltimore County. While the property hedonic model has been commonly used to value environmental benefits, few of these studies have distinguished the spatial scales of neighborhood characteristics from the property-specific characteristics within a regression model. In this research, a multilevel modeling approach to the typical property hedonic model was used to model the effects of attributes at different spatial scales. This approach also allowed the effect of environmental attributes to vary across geographic space and interact with attributes across spatial scales. Such methods provide a more realistic accounting of the dynamic spatial variation of the value of environmental goods and services. For parks in the City of Baltimore, the results of valuing proximity to parks showed a spatial dynamic not often captured in property hedonics. The overall fixed effect for distance to park was negative but insignificant. When allowed to vary by block group, the random effect for this variable indicated that only two-thirds of the 401 neighborhoods positively valued increased proximity to parks. No interactions were found to be significant for the entire study. However, for the population of block groups whose properties did positively value proximity to parks, the results of interactions with neighborhood and park characteristics showed that smaller and more open parks were valued higher than larger and more wooded parks. A high population density also increased the value for a property in close proximity to a park. Finally, properties with smaller yards placed a higher value on proximity to parks than those properties with larger yards, indicating a substitution effect. For open space in Baltimore County, the results indicated that while higher proportions of privately-owned open space surrounding a property increased the value of that property, open space that was publicly-accessible was not significantly valued. Privately-owned open space that was potentially developable was less than half the value of the positive effect of private, open space under conservation easements or other development restrictions.

Buffer strips alongside watercourses are now a widely accepted method of reducing nutrient and sediment run-off from agricultural land thereby improving water quality and meeting policy goals. However, this change in land use may have consequences for riparian biodiversity which have yet to be fully understood. This study investigated the impact of buffering on various aspects of biodiversity by comparing three types of margins in three river catchments in north east Scotland. Margins were categorised as unbuffered (open and unfenced), buffered (fenced-off vegetated) and wooded (long established woody vegetation - fenced and unfenced). Components of biodiversity studied included vegetation patterns, and the abundance, diversity, movement and assemblage composition of ground-dwelling arthropods focussing primarily, though not exclusively, on ground beetles (Coleoptera, Carabidae). This study further considered management options which may improve or enhance biodiversity. Evidenced changes in vegetation were associated with soil parameters (including decreasing pH), channel morphology, decreasing light availability and tree canopy cover, and bryophyte abundance along a successional gradient from unbuffered-buffered-wooded sites. Buffered and wooded sites showed lower activity density and species richness of ground beetles, but while one measure of functional diversity was high for wooded sites, buffered sites were found to have significantly lower values. Both species and trait assemblage structure of ground beetles were influenced by soil and vegetation, but also by features of buffer strip design such as width, length and age. Active management of sites through grazing or cutting increased ground beetle abundance, particularly hygrophilous species, but did not affect diversity. Radiotracking showed increased movement of ground beetles was correlated with intensity of grazing. Few truly riparian plant or arthropod species were identified indicating the process of buffering essentially 'terrestrialises' the riparian margins. The presence of a tree canopy layer appears to be the key instigator of change in soil conditions with vegetation and arthropods responding accordingly. Therefore planting and maintaining trees in buffer strips could be crucial to ensuring that functional diversity and associated ecosystem services are maintained. Active management through grazing or cutting could help in this regard. The results from this study suggest that rather than buffering all riparian margins within catchments, it is fundamentally important for biodiversity to maintain a mosaic of different successional stages and a diversity of habitats.

In the last few decades, a growing literature has examined how biodiversity influences ecosystem functioning. This body of work has greatly improved our understanding of ecosystem functioning and its modulation by biodiversity. In particular, there is nowadays large consensus that biodiversity increases ecosystem productivity, and stabilises ecosystems. Early investigations were largely theoretical or involved simple experiments run in laboratory conditions, but over time biodiversity ecosystem-functioning experiments evolved to more realistic field experiments that better represent the real conditions found in natural ecosystems. In particular, these experiments are often run on larger spatial scales and over longer time frames allowing for the effect of environmental heterogeneity and temporal fluctuations to be explored. The designs of these experiments evolved along with the questions addressed in this field of research. However, the analytical tools used in the analyses of these experiments followed a slightly different path. In particular, most of the metrics currently used to analyse biodiversity ecosystem functioning experiments are not entirely suited to properly deal with the complexity of modern designs as they make a number of assumptions that are not met any more. In my thesis I developed a unified framework, based on the tailored use of Linear Mixed Effects Models, to analyse biodiversity-ecosystem functioning experiments such that the new complexities of these experiments can be taken into account. This thesis aimed to bring the focus of the analysis back to the biological interpretation of the results. I successfully applied my approach to several data sets. The framework developed here is expected to improve greatly our understanding of ecosystem functioning and how biodiversity modulates it. It also sheds new light on past research in this field. The great flexibility of the new approach makes it possible to let these experiments to evolve such that new biological questions can be addressed.

The complexity of ecological and evolutionary processes that govern species distributions has long presented a challenge to understanding community assembly history. The work presented here develops a conceptual framework for integrating phylogenetics and biogeography to reconstruct the assembly of communities, provides empirical support for the broad applicability of this framework, tests whether morphology can serve as a proxy for behavioral ecology, and develops a novel metric of assemblage vulnerability and shows how vulnerability is related to biogeographic history. This dissertation demonstrates the need to merge evolution and ecology to reconstruct community assembly, and provides a framework for doing so. Further, the findings presented here suggest that such an interdisciplinary approach has the potential to both reveal fundamental processes shaping the assembly of natural systems, and to illuminate the functions and properties of ecosystems based on the evolutionary histories of their constituent species.

Deutscher Akademischer Austausch Dienst / This study investigates and analyzes the environmental licensing of the bridge over the River Coco at Sabiaguaba, Fortaleza â Cearà -Brazil. The licensing was initiated in 2001, being stopped a few times and being completed just in 2010. Through literature, and observation in the field, the public and private interests related to this building were checked. It was examined how is the lifestyles and cultural heritage of Sabiaguaba population, including their relationship with ecosystems, especially mangrove. It was analyzed howthe impacts on the natural environment were observed by the justifications given by the licensing documents and the government intitutes. For this, we examined the aspects ecodynamics and environmental services of mangrove ecosystems, including an investigation about the importance of mangrove ecosystem of the River Coco, the relationship of population of Sabiaguaba with ecosystems and environmental that exist in that area; and an analysis of the current legislation and legal doctrine that focuses on environmental licensing / Este estudo investiga e analisa o licenciamento ambiental da ponte sobre o rio CocÃ, no bairro Sabiaguaba, em Fortaleza â CearÃ. O licenciamento foi iniciado em 2001, sofrendo a obra paralisaÃÃes e sendo finalizada apenas em 2010. AtravÃs de pesquisa bibliogrÃfica, documental e observaÃÃo em campo, foram verificados os interesses pÃblicos e privados relacionados a essa construÃÃo e examinado como o modo de vida e o patrimÃnio cultural da populaÃÃo de Sabiaguaba, incluindo-se a sua relaÃÃo com os ecossistemas, principalmente o manguezal, e como os impactos sobre o meio ambiente natural foram observados pelas justificativas apresentadas pelos documentos do licenciamento e pelos ÃrgÃos envolvidos em torno da obra. Para isso, examinou-se os aspectos ecodinÃmicos e os serviÃos ambientais dos ecossistemas manguezais, investigando-se a importÃncia do ecossistema manguezal do rio CocÃ; a relaÃÃo da populaÃÃo de Sabiaguaba com os ecossistemas e os fluxos ambientais existentes naquela Ãrea; alÃm de uma anÃlise da legislaÃÃo vigente e da doutrina jurÃdica que versa sobre licenciamento ambiental.

This research is a case study evaluation of the use of self-organising map (SOM) techniques for ecosystem modelling to overcome the perceived inadequacies with conventional ecological data analysis methods. SOMs provide an analytical method within the connectionist paradigms of artificial neural networks (ANNs), developed from concepts that evolved from late twentieth century neuro-physiological experiments on the cortex cells of the human brain. The rate and extent at which humans influence environmental deterioration with commensurate biodiversity loss is a cause for major concern and to prevent further degradation by human impact, parsimonious models are urgently needed. Indeed, the need for better modelling techniques has never been so great. Ecologists and many national and international bodies see the situation as 'significantly critical' for the conservation of our global ecosystem to foster the continued wellbeing of humanity on this earth.The thesis investigates and further refines SOM based exploratory data analysis methods for modelling naturally evolving, highly diverse and extremely complex ecosystems. Earlier studies provide evidence on SOM ability to analyse complex forest and freshwater biological community structures at limited scales. On the other hand, growing concerns over conventional methods, their soundness and ability to model large volumes of data are seen as of little use, leading to arguments on the results derived from them. Case study chapters illustrate how SOM methods could be best applied to analyse often 'cryptic' ecosystems in a manner similar to that applied in modelling highly complex and diverse industrial system dynamics. Furthermore, SOM based data clustering methods, used for financial data analysis are investigated for integrated analysis of ecological and economic system data to study the effects of urbanisation on natural habitats.SOM approaches prove to be an excellent tool for analysing the changes within physical system variables and their effects on the biological systems analysed. The Long Bay-Okura Marine Reserve case study elaborates on how SOM based approaches could be best applied to model the reserve's intertidal zone with available numeric data. SOM maps depicted the characteristic microclimate within this zone from ecological monitoring data of physical attributes, without any geographical data being added. This kind of feature extraction from raw data is found to be useful and is applied to two more case studies to study the slow variables of ecosystems, such as population dynamics, and to establish their correlation with environmental variations. SOM maps are found to be capable of distinguishing the human induced variations from that of natural/ global variations, at different scales (site, regional and global) and levels using regional and global data. Hence, SOM approaches prove to be capable of modelling complex natural systems incorporating their spatial and temporal variations using the available monitoring data, this is a major advantage observed with SOM analyses.In the third case study, potential use of SOM techniques to analyse global trends on the effects of urbanisation in environmental and biological systems are explored using the World Bank's statistical data for different countries. Many state and international institutions, concerned over global environmental issues, have made attempts to develop indicators to assess the conditions of different ecosystems. The enhancements with SOM approaches against the currently recommended indicator system based on information pyramid and pressure-state-response (PSR) models are elaborated upon.The research results of SOM methods for ecosystem modelling, similar to that applied to industrial process modelling and financial system analysis show potential. SOM approaches (i.e. cluster, dependent component, decision system and trajectories/ time series analyses) provide a means for feature extraction from the available numeric data at different levels and scales, fulfilling the urgent need for modelling tools to conserve our global ecosystem. They can be used to bridge the gap in converting raw data into knowledge to inform sustainable ecosystem management. Increasingly, traditional methods based on Before-After-Control-Impact (BACI) designs and Analysis of Variance (ANOVA) are seen to be unsuitable for ecological data analysis, as they are unable to detect human induced environmental impacts from that of a natural cause. This thesis proves that SOM techniques could be applied to modelling not only a natural systems complexity but also its functioning and dynamics, incorporating spatial as well as temporal variations, to overcome the constraints with conventional methods as applied in other stated disciplines.

An examination was undertaken of the literature and restoration cases for 4 major Australian vegetation types (sclerophyll; rainforest; grassland; and wetland) to explore the proposition that ecological resilience may govern recovery after anthropogenic damage, and/or provide a fundamental guide and measure of success for ecological restoration. Also, primary data were collected from highly degraded sites (5 sclerophyll, 3 rainforest, and 4 grassy sites) to assess recovery after restoration treatment. These were supplemented with questionnaire data from practitioners working at a wider range of rainforest and sclerophyll sites, and reports from practitioners working on grassland and wetland sites. In all 4 vegetation types, species generally fell into two main groups : longer-lived 'resprouters' and shorter-lived 'obligate seeders'. But different resilience models were identified for the 4 vegetation types. The sclerophyll type exhibited higher in situ resilience but lower migratory resilience than the rainforest type, which was facilitated by flying frugivore dispersal to perch trees. Self-perpetuation was more tightly coupled with disturbance in the sclerophyll, grassland and wetland types than rainforest; and therefore 'designed disturbance' played a more obvious role in enhancing recovery within these types, than in rainforest. Results suggest that resilience (as both an ecosystem property and a theoretical concept) is fundamental to the practice of ecological restoration. Some prediction of resilience potential of particular degraded sites (and prediction of the degree and type of restoration subsidy needed) can be based on knowledge of : individual species' recovery mechanisms; resilience models for individual vegetation-types; and the site's colonisation potential and impact history / Doctor of Philosophy (PhD)