Microbes fulfill important ecosystem functions by contributing as drivers of global nutrient cycles. Their distribution patterns are mainly controlled by environmental heterogeneities. So far, little is known about the mode of action of particular environmental drivers on the microbiota, particularly in low productivity habitats. The aim of this thesis was to investigate the relationships between local environmental drivers and the microbial responses at the level of communities, individuals and realized function, using three structurally different model habitats sharing the feature of overall low productivity. Using a hypothesis-based approach and extensive 16S rRNA amplicon mapping of bacterioplankton colonizing the polar Southern Ocean, I identified how the seasonal formation of open-water polynyas and coupled phytoplankton production affected the diversity of surface bacterial communities and resulted in a cascading effect influencing the underlying dark polar water masses. Additional laboratory experiments, with cultures exposed to light, resulted in reduction in alpha diversity and promoted opportunistic populations with most bacterial populations thriving in the cultures typically reflected the dominants in situ. Furthermore it was experimentally tested how induced cyclic water table fluctuations shaping environmental heterogeneity in a constructed wetland on temporal scale, by directly affecting redox conditions. Twelve months of water table fluctuations resulted in enhanced microbial biomass, however a shift in community composition did not lead to a significant increase in pollutant removal efficiency when compared to a static control wetland. I detected phyla that have previously been proposed as key players in anaerobic benzene break-down using a protocol that was developed for single cell activity screening using isotope-substrate uptake and microautoradiography combined with taxonomic identification based on fluorescent in situ hybridization targeting the 16S rRNA. Eventually, I provide an example of how anthropogenic pollution with polyaromatic hydrocarbons induced a strong environmental filtering on intrinsic microbial communities in lake sediments. In conclusion, my studies reveal that microorganisms residing in low productivity habitats are greatly influenced by environmental heterogeneity across both spatial and temporal scales. However, such variation in community composition or overall abundance does not always translate to altered community function.

<p>In this dissertation, I explored the effects of vegetation type on ecosystem services, focusing on services with significant potential to mitigate global environmental challenges: carbon sequestration and groundwater recharge. I analyzed >600 estimates of groundwater recharge to obtain the first global combined analysis of groundwater recharge and vegetation type. Using a regression model, I found that vegetation was the second best predictor of recharge after precipitation. Recharge rates were lowest under forests, intermediate in grasslands, and highest under croplands. The differences between vegetation types were higher in more humid climates and sandy soils but proportionately, the differences between vegetation types were higher in more arid climates and clayey soils. My extensive field estimates of recharge under paired vegetation types in central Argentina and southwestern United States provided a more direct test of the relationships between vegetation and recharge. The field data confirmed the strong influences of vegetation and its interactions with abiotic factors on recharge observed in the synthesis. The results indicate that vegetation shifts have a proportionately larger potential to affect recharge in more arid climates and clayey soils.</p><p>At the same study systems, I compared my field estimates of recharge to organic carbon stocks (in biomass, litter and soil) under the different vegetation types to evaluate tradeoffs between carbon sequestration and groundwater recharge as affected by vegetation shifts. To determine net values of vegetation shifts, I combined the changes in carbon and water with reported economic values of the ecosystem services. Based on physiological tradeoffs between photosynthesis and transpiration in plants, I hypothesized that vegetation promoting carbon storage would reduce recharge and vice versa. Changes in water and carbon services were inversely proportional, with rain-fed cultivation increasing groundwater recharge but decreasing carbon storage compared to the grasslands they replaced whereas woody encroachment did the opposite. In contrast, cultivated plots irrigated with ground water decreased both ecosystem services. Higher precipitation and clay content both exacerbated changes in carbon storage with grassland conversions, whereas higher precipitation accentuated, but higher clay content diminished, those in recharge. Regardless of the nature of vegetation shift, most of the net values of grassland conversions were negative, with the shifts representing increasing costs in the following order: woody encroachment, rain-fed cultivation and irrigated cultivation. Values of changes in carbon were greater in magnitude than those of recharge, indicating that establishment of carbon markets may drive land-use changes in grasslands over water markets.</p><p>Lastly, I examined the effects of changes in subsurface hydrology resulting from grassland conversion to croplands on soil inorganic carbon stocks in the same U.S. study system. I observed significantly lower inorganic carbon stocks under both rain-fed and irrigated croplands compared to the grasslands they replaced. The losses were visible to past 6 m depth in the soil profile and were uncharacteristically rapid for the carbon pool that is considered to be relatively inert. Based on the negative relationship between the inorganic carbon stocks and recharge rates and higher estimated exports of bicarbonates in recharge under croplands, I concluded that increased recharge with cultivation resulted in dissolution and leaching of grassland soil carbonates. Ecosystem services and their relationships to biotic and abiotic factors quantified here will further our understanding of the tradeoffs and interactions between the two services through vegetation shifts.</p> / Dissertation

Plant-pollinator networks have shown to be highly dynamic systems as species and interactions change in time and space. Few studies have incorporated several habitats in their network. In this work I investigate interacting plant and pollinator communities of three adjacent habitats at Gotska Sandön, an island in the Baltic Sea. The networks varied in size between the habitats, and the larger networks of the dune and meadow displayed both nested and modular structure while the smaller forest network was more randomly organised. We found species present in more than one habitat that connected the networks by forming inter-habitat modules of tightly linked species. Species took on different topological roles in the networks depending on how many links they formed and where these attached. The habitat generalists were important to overall network structure as role correlated with habitat generalisation level.

With growing human pressures on the oceans and seas, the resulting decline of ecosystem health and biodiversity is increasingly limiting the ability of marine ecosystems to provide essential functions and resources for human wellbeing. To prevent further marine degradation, an ecosystem based approach to marine management is needed. An integral part of this is constructive stakeholder engagement. However, in a marine context, engagement is often difficult due to traditionally sectoral management and the complexity of marine issues. This thesis presents an interdisciplinary study that evaluates the potential of the ecosystem services approach to support and improve marine stakeholder engagement. First, opportunities and challenges of using the approach in participatory marine management processes were explored through interviews with 39 stakeholders who participated in the application of ecosystem service assessment to marine management in six French and UK case studies. The interviews revealed that the ecosystem services approach can facilitate participatory engagement by improving understanding of complex ecological-socioeconomic systems and fostering constructive dialogue. Second, the potential of the approach for communicating marine management decisions to marine users was tested with a scenario based survey. Responses to three versions of the survey, two with and one without ecosystem services content, were compared, showing that the ecosystem services information did not increase agreement with the management measures proposed in the scenario. An evaluation of the results in the context of environmental behaviour research suggests that the novelty and complexity of the ecosystem services approach might limit its usefulness for top down communication. In contrast, if the approach is integrated in participatory processes, it was concluded that this could have multiple benefits for ecosystem based marine management. From these findings, a conceptual model was developed that provides a normative framework for the effective use of the ecosystem services approach to support constructive participatory engagement in marine governance.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T23:18:28Z No. of bitstreams: 1 NataliaDeMedeirosPires_DISSERT.pdf: 917109 bytes, checksum: 272238860ade20f735d3f852b26b43ff (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-18T20:01:54Z (GMT) No. of bitstreams: 1 NataliaDeMedeirosPires_DISSERT.pdf: 917109 bytes, checksum: 272238860ade20f735d3f852b26b43ff (MD5) / Made available in DSpace on 2016-05-18T20:01:54Z (GMT). No. of bitstreams: 1 NataliaDeMedeirosPires_DISSERT.pdf: 917109 bytes, checksum: 272238860ade20f735d3f852b26b43ff (MD5) Previous issue date: 2015-02-24 / Beyond its importance in maintaining ecosystems, sharks provide services that play important socioeconomic roles. The rise in their exploitation as a tourism resource in recent years has highlighted economic potential of non-destructive uses of sharks and the extent of economic losses associated to declines in their population. In this work, we present estimates for use value of sharks in Fernando de Noronha Island - the only ecotouristic site offering shark diving experience in the Atlantic coast of South America. Through the Travel Cost Method we estimate the total touristic use value aggregated to Noronha Island by the travel cost was up to USD 312 million annually, of which USD 91.1 million are transferred to the local economy. Interviewing people from five different economic sectors, we show shark-diving contribute with USD 2.5 million per year to Noronha?s economy, representing 19% of the island?s GDP. Shark-diving provides USD 128.5 thousand of income to employed islanders, USD 72.6 thousand to government in taxes and USD 5.3 thousand to fishers due to the increase in fish consumption demanded by shark divers. We discover, though, that fishers who actually are still involved in shark fishing earn more by catching sharks than selling other fish for consumption by shark divers. We conclude, however, that the non-consumptive use of sharks is most likely to benefit large number of people by generating and money flow if compared to the shark fishing, providing economic arguments to promote the conservation of these species.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-09-12T13:40:35Z No. of bitstreams: 1 texto completo.pdf: 8868545 bytes, checksum: 225b7493537273bf0f117f47c3629351 (MD5) / Approved for entry into archive by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-09-12T13:41:05Z (GMT) No. of bitstreams: 1 texto completo.pdf: 8868545 bytes, checksum: 225b7493537273bf0f117f47c3629351 (MD5) / Approved for entry into archive by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-09-12T13:41:22Z (GMT) No. of bitstreams: 1 texto completo.pdf: 8868545 bytes, checksum: 225b7493537273bf0f117f47c3629351 (MD5) / Made available in DSpace on 2018-09-12T13:41:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 8868545 bytes, checksum: 225b7493537273bf0f117f47c3629351 (MD5) Previous issue date: 2018-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cities are at the core of current environmental problems and, conversely, may host the solutions for them. They are the defining ecological phenomenon of the twenty-first century. Natural patterns and processes within cities might be a means toward an ecological regeneration of their bioregions through a symbiotic relationship between them. In this context, design has a great potential to reshape cities, transforming them for improved living conditions and balanced ecological systems. Considering buildings and landscapes as reciprocal entities within a system is a great opportunity for design innovation and increased performance with an active engagement between people and nature. By assuming the ecosystem services approach as a reference for highest ecological performance when multiple ecosystem services are provided within a system, this dissertation proposes an urban ecosystem services framework and the concept of service providing design for assessing architecture and landscape architecture. This framework is the basis to analyze three rating systems that are the most relevant standards for sustainable and regenerative design of architecture and landscape architecture, being the Living Building Challenge â , LEED â , and Sustainable SITES Initiative â . Furthermore, two architecture and landscape architecture certified and high-performance projects are analyzed. Based on the analysis, other ecosystem services beyond those proposed in the framework are identified, being renewable energy sources and active living. Some ecosystem services considered are not required by the rating systems, and not provided by the projects, being medicinal resources, pollination, and spiritual experience. Although required, food production is not provided in the projects studied due to a scale issue as they are located in densely occupied urban sites. Moreover, SITES is currently more related to ecosystem services than LEED, which suggests that the ecosystem services framework has a great potential as a tool to explore the relationship of building design criteria and natural systems and cycles. Although most ecosystem services are identified as provided by the two assessed projects, their performance suggests that they are not yet fully integrated to the natural ecosystem. This fact corroborates to the necessary next step for defining the Urban Ecosystem Services Framework in a quantitative approach with a hierarchical organization of the ecosystem services. Rigorously addressing the ecosystem services approach in LEED, SITES, and other rating systems will help integrate ecological regeneration processes in architecture, landscape architecture, and cities.

No description available.

Sea level rise (SLR) is posing a great risk of flooding and inundation to coastal areas in Florida. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. In an effort to assess the economic and ecosystem service loss to coastal areas with respect to sea turtles Contingent Valuation Method (CVM) and Habitat Equivalency Analysis (HEA) were used. The CVM was used to measure the economic impacts of SLR on sea turtles. Open-ended and dichotomous choice CVM was used to obtain the willingness to pay (WTP) values of Florida residents to implement certain mitigation strategies which would protect Florida’s east coast sea turtle nesting areas. The problem of sample selection bias was reduced by surveying residents of two cities that would potentially have varying interest in coastal conservation due to their relative distance from the coast. The hypothetical WTP of Florida households to implement policies designed to protect sea turtle habitat from development encroachment was estimated to be between $21 and $29 per year for a maximum of five years. Characteristics of respondents were found to have statistically significant impacts on their WTP. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. Counter intuitively, it was found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. As the level of this awareness increased, the probability to pay the hypothetical WTP value decreased. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents’ perception regarding the importance of sea turtle population health to the ecosystem, and their confidence in the conservation methods used. iii Concepts of Habitat Equivalency Analysis were used in order to determine the ecosystem service lost due to SLR. The study area of Archie Carr National Wildlife Refuge (ACNWR) has a continually increasing sea turtle population due to various conservation efforts. However, how the inundation of the coastal area will injure this habitat was assessed, and if mitigation strategies to compensate for the loss are necessary. The carrying capacity (CC) of the refuge was chosen as the metric of the ecosystem service. Using the estimated area of ACNWR and the approximate area needed by a sea turtle to nest, the theoretical number of sea turtle nests possible on the refuge was calculated. This value was then projected to the year 2100 using the sea level rise scenarios provided by IPCC (2007) and NRC (2010). In order to quantify the injury caused by the decrease in the refuge’s CC, the number of sea turtle nests on the refuge was projected to the year 2100 using the data obtained over the past 30 years. The analysis concludes a potential loss of service to be experienced as early as 2060’s due to the carrying capacity of the refuge diminishing with the loss of the habitat due to the increase in the mean sea level.

Current agroecosystem management practices have a negative effect on natural enemies and their ability to control insect pests. Conservation biological control through the addition of flowering resources can manage food resources for natural enemies. These floral resources can also provide multiple ecosystem services. Study goals were to determine if perennial Thymus vulgaris L. was attractive to natural enemies and if so, could it be a dual use resource encouraging pest management and providing harvestable product. In 2018 plots in three locations were used to examine the effect of habitat throughout the growing season on the attractiveness of T. vulgaris. Large numbers of Thysanoptera and Hemiptera were collected in all locations, represented by phytophagous Aphididae and Thripidae, and predatory Anthocoridae. Location influenced other families to varying degrees. Seasonal specimen counts were influenced by vegetation density, floral phenology, and predator/prey relationships. In 2019 replicated plots of three treatments were used to examine if harvesting plant material affected the attractiveness of T. vulgaris to natural enemies. Total specimens in 2019 were not significantly different among treatments, indicating removal of blooms did not significantly affect the attractiveness of T. vulgaris. Significant numbers of Thysanoptera and Hemiptera were again collected in all treatments, represented by phytophagous Aphididae and Thripidae. Greater numbers of Diptera and Hymenoptera were also collected. Significant numbers of Thripidae, Aphididae, Mymaridae, and Platygastridae were found in the Family level analyses. Results from both years indicate T. vulgaris was attractive to natural enemy and phytophagous Families. Data from 2018 suggest natural enemy families were attracted to alternative prey and hosts utilizing the foliage rather than flowers but the use of nectar and pollen cannot be ruled out. Data from 2019 suggest the presence of flowers played an important role in the attractiveness of T. vulgaris to micro-hymenopteran parasitoids, Syrphidae, and native Apidae. In conclusion, Thymus vulgaris has the potential to be a dual use floral resource that benefits growers through supporting native enemy populations and pollination services, as well as provide income from the harvest of foliage. It could also be used as a beneficial, harvestable floral resource in urban gardens to encourage pollinator conservation and natural pest control.

Ecological interactions within a community shape the structure of ecosystems and influence ecosystem function. Plant-pollinator interactions exist as mutualistic exchange networks that may collapse as habitat loss occurs, thereby threatening the overall health of an ecosystem. Understanding the impacts of human-mediated habitat disturbance on ecological interactions is therefore crucial for conservation efforts. Archbold Biological Station (ABS) in Venus, Florida contains over 2000 hectares of protected Florida scrub habitat nested within a human-dominated environment that is threatened by anthropogenic habitat disturbance. In past studies, over 113 bee species and 157 associated host plants, many endemic to the Lake Wales Ridge, have been found on ABS property, providing an understanding of this system's plant-bee network. Using those data as a baseline, this study investigated the effects of varying levels of mechanical habitat disturbance intensity on the diversity and network structure of plant-bee interaction networks. Flowering plant abundance, richness, diversity, and composition as well as bee abundance and composition were significantly different across mechanical habitat disturbance levels. Interactions between bees and flowering plants also differed with varying disturbance intensity. From these results, it is clear that plants, bees and interactions between them are impacted by mechanical habitat disturbance in this system. This project informs management efforts not only for natural systems with the threat of alteration, but also for agricultural systems, many of which heavily rely on flower visitation by bee pollinators. This research also contributes to the growing field of interaction ecology by increasing understanding of habitat alteration effects on a valuable ecological interaction and ultimately ecosystem function.