Thèses sur le sujet « Biodiversity level »

The issues involved in agricultural biodiversity are important and interesting areas for the application of economic theory. However, very little theoretical and empirical work has been undertaken to understand the benefits of conserving agricultural biodiversity. Accordingly, the main objectives of this PhD thesis are to: (1) Investigate farmers’ valuation of agricultural biodiversity; (2) Identify factors influencing farmers’ demand for agricultural biodiversity; (3) Examine farmers’ demand for biodiversity rich farming systems; (4) Investigate the relationship between agricultural biodiversity and farm level technical efficiency. This PhD thesis investigates these issues by using primary data in small-scale farms, along with secondary data from Sri Lanka. The overall findings of the thesis can be summarized as follows. Firstly, owing to educational and poverty issues of those being interviewed, some policy makers in developed countries question whether non-market valuation techniques such as Choice Experiment (CE) can be applied to developing countries such as Sri Lanka. The CE study in this thesis indicates that carefully designed and pre-tested nonmarket valuation techniques can be applied in developing countries with a high level of reliability. The CE findings support the priori assumption that small-scale farms and their multiple attributes contribute positively and significantly to the utility of farm families in Sri Lanka. Farmers have strong positive attitudes towards increasing agricultural biodiversity in rural areas. This suggests that these attitudes can be the basis on which appropriate policies can be introduced to improve agricultural biodiversity. Secondly, the thesis identifies the factors which influence farmers’ demand for agricultural biodiversity and farmers’ demands on biodiversity rich farming systems. As such they provide important tools for the implementation of policies designed to avoid the loss agricultural biodiversity which is shown to be a major impediment to agricultural growth and sustainable development in a number of developing countries. The results illustrate that certain key household, market and other characteristics (such as agricultural subsidies, percentage of investment of owned money and farm size) are the major determinants of demand for agricultural biodiversity on small-scale farms. The significant household characteristics that determine crop and livestock diversity include household member participation on the farm, off-farm income, shared labour, market price fluctuations and household wealth. Furthermore, it is shown that all the included market characteristics as well as agricultural subsidies are also important determinants of agricultural biodiversity. Thirdly, it is found that when the efficiency of agricultural production is measured in practice, the role of agricultural biodiversity has rarely been investigated in the literature. The results in the final section of the thesis show that crop diversity, livestock diversity and mix farming system are positively related to farm level technical efficiency. In addition to these variables education level, number of separate plots, agricultural extension service, credit access, membership of farm organization and land ownerships are significant and direct policy relevant variables in the inefficiency model. The results of the study therefore have important policy implications for conserving agricultural biodiversity in Sri Lanka.

The objectives of this thesis relate to questions needed to be addressed in the context of genetic monitoring for implementing the Convention on Biological Diversity for the gene level. Genetic monitoring is quantifying temporal changes in population genetic metrics. Specific goals of this thesis include i) synthesizing existing information relevant to genetic monitoring of Swedish species, ii) providing a genetic baseline for the Swedish moose, iii) evaluating the relative performance of nuclear versus organelle genetic markers for detecting population divergence, iv) actually monitoring the genetic composition, structure, level of variation, and effective population size (Ne) and assessing the relation between Ne and the actual number of individuals for an unexploited brown trout population. The concept of conservation genetic monitoring is defined and Swedish priority species for such monitoring are identified; they include highly exploited organisms such as moose, salmonid fishes, Norway spruce, Atlantic cod, and Atlantic herring. Results indicate that the Swedish moose might be more genetically divergent than previously anticipated and appears to be divided into at least three different subpopulations, representing a southern, a central, and a northern population. The relative efficiency of nuclear and organelle markers depends on the relationship between the degree of genetic differentiation at the two types of markers. In turn, this relates to how far the divergence process has progressed. For the monitored brown trout population no indication of systematic change of population structure or allele frequencies was observed over 30 years. Significant genetic drift was found, though, translating into an overall Ne-estimate of ~75. The actual number of adult fish (NC) was assessed as ~600, corresponding to an Ne/NC ratio of 0.13. In spite of the relatively small effective population size monitoring did not reveal loss of genetic variation.

Magister Scientiae - MSc (Biodiversity and Conservation Biology)
Arundo donax is an invasive species that mostly impacts on sensitive riparian ecosystems. Arundo is also invasive in South Africa, though less is known about its ecology, biology, and impacts. Since California and the Western Cape of South AFrica have similar Mediterranean-type climates, we could assume that the impacts of Arundo on ecosystems in California are likely to be similar in the Western Cape, and that control methods used could be extrapolated for use in South Africa. This thesis attempted to determine what impact Arundo has on biodiversity at the community-ecosystem level.
South Africa

Biodiversity research aims to understand and predict the occurrence, abundance, and distribution of species and the diversity of species traits, body sizes, and functional roles in a community. Ecologists lack a comprehensive understanding of the interplay between processes driving biodiversity at differing spatiotemporal scales, hindering the ability to predict response to change. A crucial challenge facing ecologists is to incorporate knowledge of the regional dynamics and temporal stability of communities in biodiversity research. This dissertation investigates the role that species traits and system-level properties play in determining biodiversity at local sites and evaluates biodiversity response to change. Local and regional processes may regulate biodiversity via their different influences on core (common, temporally persistent) and transient (rare, temporally intermittent) species. In Chapter 2, we tested the hypothesis that core vs. transient species have fundamentally different life-history traits that are associated with survival strategies targeted at local vs. regional habitat use. Using long-term mark-recapture data from a rodent community, we found that core species generally had high ecological specialization, high survival, low dispersal rates, and low reproductive effort compared to transient species. Life-history trade-offs may correspond to differing roles in maintaining species richness and responses to environmental change. Macroecology describes patterns of biodiversity in communities without respect to species identities or traits. Diversity patterns (i.e., species-abundance distribution-SAD, species-area relationship-SAR, species-time relationship-STR) are well-studied, but drivers of these patterns are poorly understood. In Chapter 3, we tested the hypothesis that local-scale interactions influence the form of SADs, SARs, and STRs using long-term data from annual plant communities. Our results suggest that patterns are directly influenced by system-level properties (species richness, total abundance) and respond indirectly to local-scale processes. In Chapter 4, we analyzed data from a global-span database and found the SAD and species richness generally resilient to environmental change. This work suggests that local processes are important determinants of species composition and abundance and may set an upper limit to species richness, but that regional processes are responsible for maintaining richness and community structure. This insight may partially explain why many biodiversity metrics are often invariant under environmental change scenarios.

Biodiversity is a fundamental part of the functioning of ecosystems and their ability to provide ecosystem services. It has been shown that a high biodiversity increases the robustness of an ecosystem according to the insurance hypothesis. I propose that a similar effect can be seen on a higher scale, where a high diversity of ecosystem types might stabilize the ecological functionality of a region. By comparing eleven network characters in 70 tropical and temperate ecosystems, their diversity was measured as Euclidean distance between the systems in the 11-dimensional room defined by these characters.  The diversity of ecosystems was shown to be significantly higher in tropical latitudes than in temperate. A possible explanation to this result could be that the higher species diversity in the tropics allows for more types of ecosystems. A higher diversity of ecosystems in a region might indicate a larger amount and variation of possible ecosystem goods and services as well as provide the region with an increased robustness. The measurement of ecosystem diversity between regions might also be of importance in a conservation perspective, where unique and vulnerable ecosystems can be discovered and protected.

Att bevarandet av biologisk mångfald är en grundpelare för att nå en hållbar utveckling enades världens länder om i Konventionen om biologisk mångfald (CBD) som upprättades under toppmötet i Rio de Janeiro 1992. I konventionen förespråkas den s.k. ekosystemansatsen (EA), vilket är en strategi som innebär en helhetssyn på ekosystem. Syftet med denna uppsats är att undersöka i vilken grad EA tillämpas på nationell och regional nivå. Frågan är också om EA är en bra utgångspunkt för att upprätthålla biologisk mångfald på landskapsnivå samt vad som kan öka tillämpningen av EA på regional nivå. På nationell nivå analyserades två delar i miljömålspropositionen och på regional nivå analyserades de landskapsstrategier som sju län har fått i uppdrag av regeringen att upprätta i ett pilotprojekt. Min teoretiska utgångspunkt har varit ekosystemansatsen och dess principer och vägledande punkter. Metoden bestod av främst en kvantitativ innehållsanalys med kvalitativa inslag och som komplement utfördes fyra intervjuer.

Resultatet visade att de delar av miljömålspropositionen som analyserades i hög grad följde ekosystemansatsen. En brist i propositionen var dock att det saknades riktlinjer om att det behövdes involvering av olika aktörer när den ursprungliga definitionen av landskapsavsnittet i strategierna skulle bestämmas. Att denna aspekt var implicit ledde troligtvis till det faktum att den även var implicit i landskapsstrategierna. Tillämpningen av EA i landskapsstrategierna skedde, trots att länsstyrelserna endast tillämpade den indirekt, i ganska hög grad och särskilt togs hänsyn till sociala aspekter som involvering av olika aktörer i själva processen och kontakt med vetenskapliga discipliner. Det som däremot var bristfälligt gällde tillämpningen av komplexa aspekter, vilka inte klart hade uttryckts i riktlinjerna till länsstyrelserna från regeringen. Dessa faktorer var beaktande av förvaltning av ekosystem inom ramen för dess funktion, processer i ekosystem samt adaptiv förvaltning. Alla intervjupersoner var överens om att EA är övergripande och ganska luddig, men det måste den vara för att gälla globalt. Av vikt är att konkretisera den på nationell och regional nivå. Ett förslag är att Naturvårdsverket i detta projekt ger tydliga riktlinjer angående tillämpningen av EA i landskapsstrategierna och att det är en tvåvägskommunikation mellan Naturvårdsverket och länsstyrelserna så att det blir en iterativ process. Genom en konkretisering kan tillämpningen av EA öka och därmed ett steg tas mot en hållbar utveckling.

The Convention on Biological Diversity (CBD) promotes the Ecosystem Approach (EA), which is a strategy that endeavours to take a comprehensive approach to managing ecosystems. The aim of this report is to study to what degree the EA is being followed on a national and regional level. A key question of the research is whether EA is conceptually sound and whether it has been operationalised effectively at both national and regional scale. Using articulated EA principles and operational guidelines from the CBD this study analyzed the Government's national environmental directive concerning biodiversity. The same approach was also applied to an analysis of several regional landscape strategies that are being developed as part of a pilot project. The results show that the national biodiversity directive is largely consistent with an EA. Although one area of inadequacy was the level of involvement by different stakeholders in the original decision about defining the landscape area in the pilot studies. This was also a weakness in the landscape strategies- perhaps because communication on this issue was not explicit in the directive from the government.

The implementation of EA in the landscape strategies at the regional level was also found to be good, especially the participation from different stakeholders (especially local stakeholders) in the process and scientific institutions. However inadequate factors not represented in these strategies were complex ecological aspects such as principle 6 (ecosystem must be managed within the limits of their functioning) and operational guideline 1 (focus on the functional relationships and processes within ecosystems). Adaptive management (operational guideline 3), a relatively new approach in Sweden, was also found to be deficient. All the respondents agreed that the EA needed to be made more concrete on a national and regional level. A suggestion from the research to improve the development and adoption of the EA would be to develop iterative mechanisms between regional and national authorities to ensure national guiding principles are informed by more concrete regional experience. When the EA is implemented more effectively we will take one step further on the way to reaching a sustainable development.

This thesis considers ways to improve biodiversity conservation at the bioregional level in Australia through the use of geospatial science technologies and biological modelling techniques. Following a review of approaches to biodiversity conservation at the bioregional level, including the roles and potential of geospatial science technologies in this regard, I consider biodiversity modelling using a case study of the Burt Plain bioregion in central Australia that focuses on selected taxa, ecosystems and landscapes. The Burt Plain bioregion was chosen since it is one of 19 bioregions nationally that has been given a 'very high' priority status for biological survey, assessment and potential reservation of land for conservation purposes. The specific research objectives for the Burt Plain bioregion study were to: · describe the species composition, distribution and nature of the dominant vegetation communities within the bioregion; · characterise environmental niche of communities with respect to selected environmental and management variables - latitude, longitude, climate, land systems and land units, geology, hydrography, topography, and tenure; · analyse how well or otherwise taxa have been sampled (during previous ground surveys) with respect to geographical and environmental variables; Biodiversity conservation at the bioregional level · develop and compare quantitative habitat models of the potential distribution of selected species based on presence-only distributional data; and · examine the significance of radiometric data as a potential correlate and predictor of the distribution of those selected species. National conservation initiatives such as the bioregional approach and international initiatives such as the biosphere reserves program to support the planning and management of biodiversity conservation are discussed in chapter two. The scientific and related processes underpinning the development of bioregions and strategies across the Australian states and territories are then considered. An important finding arising from this review is the need to improve biological information, especially through systematic surveys and on-going monitoring of ecosystems and populations of species, at the bioregional level to inform land use allocation and management. This finding is consistent with one of the general aims of the thesis to improve the spatial modelling techniques available for bioregional assessment and biodiversity conservation. In chapter three I review the role and limitations of geospatial technologies currently employed for biodiversity conservation management. Current developments and applications of GIS and remote sensing to wildlife research, conservation gap analysis and conservation reserve design are considered. Geographic information systems (GIS) are now routinely used by ecologists to Biodiversity conservation at the bioregional level analyse spatial data. Although various forms of GIS have been available for 15 to 25 years, the biological applications of GIS have figured most prominently in the ecological literature only in the past 15 years. The use of computer-generated models to simulate environmental events can provide a greater understanding of ecosystems, and offers improved predictive powers to conservation and land managers. The decision support offered by computer-based modelling techniques appears likely to underpin conservation and management decisions much more into the future providing that adequate biological and other datasets are available for this purpose. Dominant vegetation communities and various environmental gradients were analysed to characterise environmental niches at the bioregional scale for the Burt Plain bioregion (Chapter 4) and more locally at the catchment scale for the Upper Todd River Catchment (Chapter 5). In Chapters four and five I describe in detail the land tenure and use, land systems, climate soil, geology, topography, hydrology, vegetation and biodiversity of the Burt Plain bioregion and Upper Todd River Catchment. The bioregion contains some ephemeral watercourses, which are generally in fair to good condition, but are afforded little protection from a range of threatening processes, including grazing and trampling by feral animals and livestock and weed infestation. The major river systems occurring in the bioregion include parts of the Plenty, Hanson, Sandover and Lander Rivers. In the Upper Todd River Catchment the major watercourses Biodiversity conservation at the bioregional level are the Todd River and Station Creek, which exit the area via two narrow gaps in the low rocky hills on the southern boundary of the bioregion. The dominant geology can be summarised as plains and low rocky ranges of Pre-Cambrian granites on red earths. The bioregion has approximately 200 - 250 mm of summer rainfall, with rainfall occurring on 20 - 30 days per year. There is a high variability and range of temperatures, with an annual mean temperature of approximately 22-23°C. In Chapter six I consider a range of species found within the Burt Plain bioregion using existing survey data and techniques that enables the prediction of the spatial distribution of taxa. Using GLM and GAM models, Black-footed Rock- Wallaby (Petrogale lateralis), Spinifex Hopping Mouse (Notomys alexis) and Spencers Frog (Limnodynastes spenceri) were chosen for a more in-depth analysis. Environmental variables correlated with the presence of each species are then described and prediction maps showing the probability or likelihood of the presence of the species within the bioregion developed. In Chapter seven I examine the utility of radiometric data for wildlife habitat modelling. Statistical relationships are tested between the concentrations of the elements uranium, thorium and potassium and terrain characteristics such as position in the landscape, slope and aspect as well as other climatic variables. Radiometric data were found to be useful for developing statistical predictive Biodiversity conservation at the bioregional level models of six species: Red Kangaroo (Macropus rufus), Desert Dunnart (Sminthopsis youngsoni), Rabbit (Orcytolagus cuniculus), Brown Honeyeater (Lichmera indistincta), Little Spotted Snake (Suda punctata) and Southern Boobook (Ninox novaeseelandiae). I suggest that the utility of radiometric data for wildlife habitat modelling would appear significant and should be explored further using alternative quantitative modelling techniques and presence/ absence records for target faunal species. Predictions of species distributions may be useful for prioritising land acquisitions for reservation as well as in the future design of biological surveys. The thesis concludes with a synthesis of the major research findings, discussion of the limitations of the datasets available for the study, perspectives on management issues in the Burt Plain bioregion, and possible future research directions. It is important that purposefully-designed biological survey research be undertaken across the bioregions of the arid zone of Australia to enhance basic understanding of biodiversity patterns and their relationships to environmental heterogeneity and site-landscape level processes. Geospatial modelling techniques can assist such biodiversity survey and evaluation and make their conduct more cost-efficient and the inferences drawn from subsequent data analyses more powerful. This knowledge is required to contribute to the emergent concepts and theory of ecosystem dynamics and associated biodiversity patterns in arid Australia and, most significantly, to enhance the conservation and management of the unique biological complement and systems found in this region.

Nous traversons actuellement une crise de perte de la biodiversité sans précédant. La dégradation des sols et la perte d’habitat, la pollution, la surexploitation et les invasions biologiques contribuent à cette perte mondiale de biodiversité. Par ailleurs, le changement climatique et ses interactions avec les autres menaces, sont probablement l’un des défis majeurs des prochaines décennies pour la biodiversité. À l’heure actuelle, en raison de la multiplication des études et des approches employées, il est difficile d’avoir une vision synthétique des conséquences potentielles de ces changements sur la biodiversité. L’objectif principal de ce travail de thèse a été d’améliorer la caractérisation et la quantification des différents impacts des changements climatiques sur la biodiversité, à l’échelle mondiale par des approches de modélisations et de méta-analyses. Une première partie de mes travaux a ainsi porté sur les conséquences potentielles de la hausse du niveau des mers sur les hotspots insulaires, au cours de laquelle j’ai mis en évidence les conséquences majeures d’une telle hausse pour certains de ces hotspots. Je me suis ensuite intéressée à l’étude des effets conjugués des changements climatiques et des changements d’utilisation des sols sur les invasions biologiques à l’échelle mondiale. Cette partie a permis de mettre en évidence que les conséquences des changements climatiques et des changements d’utilisation des sols sur les espèces invasives dépendent de la région, du taxon et de l’espèce considérée. Ainsi, j’ai mis en évidence que certaines régions pourraient être moins favorables à la présence d’espèce invasives dans le futur. En outre, cette partie a également mis en évidence que les hotspots majoritairement composés d’îles étaient particulièrement favorables à la présence de ces espèces invasives. Finalement, dans une dernière partie, j’ai étudié les conséquences des menaces futures pour les hotspots de biodiversité dans une perspective de conservation. Cette partie a notamment permis d’établir des priorités de recherche et de conservation entre les hotspots de biodiversité en tenant compte des futures menaces qui pèsent sur la biodiversité à l’échelle des hotspots, mais également au sein même des hotspots de biodiversité. Cependant, la mise en œuvre de plans de gestion de sauvegarde d’habitats ou d’espèces ne pourra se faire qu’en intensifiant les collaborations avec l’ensemble des acteurs impliqués. Plus généralement, la mise en œuvre de stratégies d’atténuation et d’adaptation efficaces aux changements climatiques ne pourra pas avoir lieu sans un soutien du grand public
Global biodiversity is changing at an unprecedented rate due to loss of habitat, biological invasions, pollution, overexploitation. Furthermore, climate changes and their synergies with other threats will probably become the main drivers of biodiversity loss in the next century. Nowadays, the multiplicity of approaches and the resulting variability in projections make it difficult to get a clear picture of the future of biodiversity due to climate change. Yet, the majority of models indicate alarming consequences for biodiversity, with the worst- case scenarios leading to an increase of extinction rates. The aim of this thesis was to improve the knowledge about of the different consequences of climate change on biodiversity worldwide. To do that I mainly used modelisation and meta-analyses approaches. The first part of my work was to investigate the consequences of sea level rise for the ten insular biodiversity hotspot and their endemic species, during which I highlighted that between 6 and 19% of the islands would be entirely submerged. Then I studied the effects of climate and land use changes on biological invasions worldwide. The results showed that invasives species response to climate and land use changes depend on region, taxa and species considered. We also emphasized that some regions could lose a significant number of invasive alien species. Besides, we also found that hotspot that are mainly islands or group of islands are highly suitable for invasive species. Finally, in the last part, I quantified the exposure of biodiversity hotspots to the combined effects of climate change, land use change and biological invasions. This work highlighted the pressing need to consider different drivers of global change in conservation planning. In addition, we established some prioritization framework among the hotspot. Finally, conservation strategies to protect habitat and species under global changes, can only be achieved through closed collaboration with park managers. Overall, implementation of effective adaptation strategies to climate change can only succeed with public support

There is a recognised need to turn the abstract concept of resilience thinking into practical action for resource management. This is often difficult as resource management is complex and multifaceted. Nexus thinking attempts to address this by promoting a framework that integrates and coordinates resource management across many different but interlinked resource pillars and sectors. This research focuses on the local level implementation of the food, energy, water, land and biodiversity (FEWLB) nexus framework, and assesses farmers' understanding and implementation of nexus thinking in relation to the support of the Bergrivier Municipality. Agriculturalists (farmers) have been described as significant custodians of natural resources, as they sit in a key position when it comes to implementing and practising sustainable development. There has been little research into the relationship between farmers and local municipalities, or into the role that local government can play in supporting holistic resource management through agriculture. While there are many different actors contributing towards resource management, this research focuses on the agricultural sector within the municipality. Qualitative research methods, including semi-structured interviews, participant observation and surveys, were used to undertake a case study of the agricultural sector within the Bergrivier Municipality. In a context where local government struggles to find its role in supporting socio-ecological resilience, the FEWLB nexus framework offers an opportunity to implement effective planning and policies that could enable more efficient resource use.

Thesis (Ph.D.)--University of Cincinnati, 2008.
Advisor: Arnold I. Miller. Title from electronic thesis title page (viewed Sep. 4, 2008). Keywords: fossil biodiversity; richness; evenness; Cincinnatian; rarity; ecological gradient; latitudinal diversity gradient. Includes abstract. Includes bibliographical references.

Numerous causes have been implicated in contributing to amphibian population declines since the 1980's, with habitat modification, ultraviolet radiation (UV-B) and environmental contaminants (such as glyphosate-based herbicide) being among the most common. This study identifies the effects of a generic glyphosate-based herbicide (GLY- 4 Plus) on mortality, immune function, body condition, and morphological plasticity of larvae of the spotted salamander (Ambystoma maculatum) under conditions that reflect open and closed canopy light regimes. Larval salamander responses to glyphosate-based herbicide varied depending on UV-B conditions. In general, it appears that an open canopy (i.e. greater UV-B exposure) may confer fitness benefits. In the presence of herbicide, survival was higher in an open canopy UV-B regime and pooled open canopy survival was higher than that of closed canopy treatments. In the absence of herbicide, body condition and immune function were positively related with amount of UV-B. Finally, herbicide presence appeared to affect morphology under low UV-B conditions. UV-induced breakdown of surfactant or a complex interaction between temperature stratification and trophic relations is potentially responsible for the observed patterns in survival and body condition. However, the mechanistic underpinnings of improved immune function and morphological differences are less clear. As deforestation is likely to continue, amphibians may find themselves in ponds with increasingly open canopies. Combined with the knowledge that some amphibians can become locally adapted to UV exposure and develop pesticide tolerance, the probability of surviving exposure to this herbicide may be elevated in open canopy ponds. These results emphasize the complexity of natural systems and the importance of including multiple factors in experiments.

Over the last 3 decades, freshwater aquaculture has become one of the most important food industries. However the constant introduction of a reduced number of very successful species for aquaculture has been identified as one of the main activities related to the alarming decline of fish biodiversity worldwide. This issue has raised awareness amongst the scientific community, governmental authorities and the general public towards freshwater fish biodiversity. This new awareness has promoted the development of “green” markets and environmentally friendly strategies, aiming for a reliable production of protein sources. The development of native species aquaculture has been presented as a strong alternative for sustainable aquaculture and the protection of biodiversity. However, it seems clear that unplanned native species aquaculture developments can be as detrimental on local biodiversity as the introduction of exotic fish, if not more dangerous. Therefore, the advantages and disadvantages of native species aquaculture have to be clearly analysed before any aquaculture development. This study aimed to establish a philosophical background regarding the use of native fish species in aquaculture in contrast to the introduction of exotic species that may compete for a similar niche as food in local markets. The main ecological impacts that exotic fish species may have on natives, such as competition, predation, and hybridization were discussed. In addition, a well planned native species Aquaculture Strategy for the Protection of Biodiversity was produced, at catchment level, within a Geographic Information System (GIS). For the development of the native species aquaculture strategy in central Mexico, four species of Atherinids (Chirostoma estor, C. Jordani, C. promelas and Atherinella balsana) and two species of native Ictalurids (Ictalurus balsanus and Ictalurus dugesii) were included in this study. These six species are relatively new to aquaculture and they were selected on the basis of their importance in local fisheries and markets in their native basins of the Lerma-Santiago and Balsas rivers. Both of these basins are of great importance in central Mexico, not only because of their biodiversity but also because of their high human population densities and socio-economic status. The use of Geographic Information Systems was a fundamental factor in the development of the native species aquaculture strategy at catchment level, consisting of site suitability models (SSM) for each species in their corresponding native catchments. Overall, SSM identified 13,916 km2 and 11,178 km2 highly suitable for aquaculture of the studied Atherinids and Ictalurids respectively, based on Water, Soil and Terrain, Infrastructure and Risk sub-models. A set of predictive species distribution models (PSDM), which related ecological characteristics for each studied species with relevant environmental and topographic parameters into a GIS, were also produced. Such models were developed for the establishment of potential natural ranges of distribution for each species, as well as their potential to become exotic in new environments, as a potential for invasion model (PI). Based on a partial verification, both PSDM and PI models produced results that were satisfactorily consistent with the known distribution of each modelled species. The combination of SSM and PSDM produced an Aquaculture Strategy for the Protection of Biodiversity model (ASPB) which identified the most environmentally friendly suitable areas for aquaculture sites. In contrast, the combination of the SSM with PI models into an ASPB model identified the site suitability potential for non-native species that are genetically close to native ones, in an attempt to reduce the known impacts that exotic species have on local biodiversity. In this way the ASPB model identified 7,651 km2 suitable for aquaculture of I. balsanus in its native Balsas basin and 15,633 km¬2 suitable for aquaculture of the non-native I. dugesii. ASPB models were produced for all the studied species. The final results were used to produce a set of guidelines for the development of sustainable aquaculture of native species at catchment level that cover genetic and ecological implications, as well as a well planned decision making tool produced in a GIS.

Snakes represent an impressive evolutionary radiation of over 3,500 widely-distributed species, categorized into 515 genera, encompassing a diverse range of morphologies and ecologies. This diversity is likely attributable to their distinctive morphology, which has allowed them to populate a wide range of habitat types within most major ecosystems. In my first chapter, I provide the largest-yet estimate of the snake tree of life using maximum likelihood on a supermatrix of 1745 taxa (1652 snake species + 7 outgroup taxa) and 9,523 base pairs from 10 loci (5 nuclear, 5 mitochondrial), including previously unsequenced genera (2) and species (61). I then use this phylogeny to test hypotheses regarding heterogeneity in diversification rates and how this shaped overall patterns of snake diversity in Chapter 2. I also used the species-level phylogeny to test the evolution of habitat use in snakes, morphological variation, and whether distantly-related species exhibit morphological convergence in Chapter 3. Finally, in Chapter 4 I investigate how prehensile tails effect striking performance in arboreal snakes.

Although water quality improvement is generally the primary objective of treatment wetlands, the creation of habitats is an inevitable outcome of these projects. Macroinvertebrate are often early colonists of new created wetlands, with abundance and diversity approaching high levels within a few years from wetland construction. A deeper knowledge of the biodiversity hosted in these environments is needed to evaluate if newly created ponds are appropriate management tools for biological conservation. The effectiveness of the interventions provided by Parco Pineta di Appiano Gentile e Tradate (a regional park in Lombardy, Italy) in freshwater ecosystem management and restoration has been evaluated, considering a set of natural, artificial and constructed wetlands spread within the park territory. Considering the macroinvertebrate community and analyzing the biodiversity hosted in all the considered wetlands, no significant differences were found between artificial and natural ecosystems. Even the constructed wetlands, which were characterized by low water quality and higher pollutants concentrations, presented a biodiversity level which in some cases exceeded that one present in natural ecosystems. Even though biodiversity was similar between wetland typologies, differences in community compositions have been enlightened. The macroinvertebrate community assemblages seemed to be influenced more by the geographical and hydromorphological variables of the ecosystem rather than the physicochemical water characteristics. In particular, water body area and habitat heterogeneity resulted to be the most important variables that influenced the community composition. Seasonal variations in hydrological conditions and resource availability were the main factors that influenced the macroinvertebrate dispersal, evaluated considering life-strategy groups. Although the considered ponds and wetlands presented different features, they all contributed to the local ecological network even if they were not all equally interconnected together. All the collected information could be useful to design further possible interventions for conservation aims.

Understanding the drivers and patterns of biological diversity has been a central tenet for ecologists over the past century. Aquatic ecosystems appear to be particularly sensitive to biodiversity declines and thus comprehending the causes of these biodiversity losses has become a pressing issue. The objectives of this thesis are twofold. First, I wanted to investigate the effect of phosphorus, a surrogate for productivity in aquatic ecosystems, on the diversity of two taxonomic groups across broad spatial and temporal scales. Secondly, I wanted to quantitatively assess the use of biodiversity indicators in aquatic ecosystems, with particular emphasis on the role of body size. In the first chapter of this thesis, I took a palaeolimnological approach to investigate how the species richness of subfossil diatoms and cladocera varies in response to phosphorus. From both our spatial and temporal analyses, a significant decline in species richness of diatoms and cladocera was observed as phosphorus increased. When subdivided according to habitat preference, only the littoral species richness showed a decline in species richness. We attribute this decline in species richness in the littoral taxa to the interplay of nutrients on littoral habitat heterogeneity. At low levels of phosphorus, the littoral zone is thought to be more productive and harbor a greater abundance of submerged macrophytes and is thus able to maintain a more diverse community. The second chapter of this thesis investigated the efficiency of cross-taxon congruence as a method for estimating biodiversity in aquatic ecosystems. I approached this subject by performing a spatial field study coupled to a meta-analysis of the published literature. The field survey and meta-analysis show that organisms of similar size tended to exhibit more congruent diversity patterns. I argue that this pattern arises because organisms of similar body size have similar life history traits and thus similar biodiversity responses to environmental gradients. I demonstrate that cross-taxon biodiversity indicators are most effective when estimating the diversity of communities of most similar body size. Overall, this research has expanded our understanding of patterns, drivers and similarities of biodiversity across trophic levels in aquatic ecosystems.
Au cours du siècle dernier, plusieurs écologistes ont tenté de comprendre les caractéristiques ainsi que les facteurs qui contrôlent la diversité biologique. Les écosystèmes aquatiques semblent être particulièrement sensibles au déclin de la biodiversité et donc en découvrir les causes devient alors une question pertinente. Cette thèse possède deux objectifs. Tout d'abord, je souhaite étudier l'effet du phosphore, un substitut de productivité dans les écosystèmes aquatiques, sur la diversité de deux groupes taxonomiques à travers de grandes échelles spatiales et temporelles. Deuxièmement, je désire évaluer, de façon quantitative, les indicateurs de biodiversité dans les écosystèmes aquatiques, et ce, en mettant l'emphase sur le rôle de la dimension des organismes. Dans le premier chapitre de cette thèse, j'ai utilisé une approche paléolimnologique pour étudier comment la richesse spécifique des diatomées et des cladocères fossilisés varie en fonction du taux de phosphore. Grâce à mes analyses temporelles et spatiales, j'ai noté une baisse significative de la richesse spécifique des diatomées et des cladocères avec une augmentation du phosphore. De plus, lorsque les communautés étaient divisées par leurs préférences d'habitat, seules les richesses spécifiques littorales ont démontré un déclin en fonction du phosphore. J'attribue ce déclin de la richesse spécifique dans les groupes littoraux à l'effet des nutriments sur l'hétérogénéité des habitats littoraux. À de bas niveaux de phosphore, la zone littorale est plus productive et peut accueillir de grandes abondances de macrophytes qui fournissent plus de niches écologiques pour les espèces, donc une plus grande diversité.Le deuxième chapitre de cette thèse porte sur l'utilisation de la richesse spécifique d'une communauté d'organismes pour estimer la richesse spécifique d'une autre. Cette méthode de substitution est utilisée pour estimer la biodiversité dans les écosystèmes aquatiques. J'ai abordé ce sujet en effectuant une étude spatiale jumelée à une méta-analyse des écrits. Mon analyse spatiale et ma méta-analyse illustrent que les groupes taxonomiques ayant des dimensions similaires ont tendance à présenter des patrons de diversité plus conformes. Je suppose que les organismes de tailles similaires démontrent plus de similarité en ce qui concerne leurs traits de vie et à leurs patrons de diversité lors de gradients environnementaux. Je démontre que les indicateurs utilisés pour prédire la biodiversité sont plus efficaces lorsque leurs tailles sont plus similaires. Conséquemment, cette recherche a permis d'agrandir nos connaissances des patrons, des processus et des similitudes de la richesse spécifique dans les écosystèmes aquatiques.

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BITTENCOURT-SILVA, Gabriela Bueno. Insular Anuran (Amphibia) Communities of the Southeast Coast of Brazil: Taxonomic Composition and Relationship to the History of the Islands. 2011. 72p. Dissertation (Master of Science in Animal Biology). Instituto de Biologia, Departamento de Biologia Animal, Universidade Federal Rural do Rio de Janeiro, Serop?dica, RJ, 2011. A data set containing a list of the known species of frogs that occur near shore and on eight islands of the south coast of the State of Rio de Janeiro and north of the State of S?o Paulo was produced. For that, I compiled data from the literature and conducted inventories of a few of the islands. This list included 67 anuran species belonging to 11 families for eight islands and 117 species and 14 families for two localities on the mainland. The pattern of richness between islands was analyzed in respect to the island area and the composition of habitats used by the anurans for reproduction. Insular structural complexity was also evaluated in this regard. The results of correlation analyses of area vs. species richness and species richness vs. number of reproductive habitats were highly significant indicating that species richness prediction in fragmented environments depends on both factors. Nestedness analyses using the metric NODF was performed in an attempt to investigate whether shared species absences among the islands are the result of a random process or represents a pattern indicative of ordered loss of species. The predicted pattern was confirmed ? that is, that species loss is nonrandom and that this was possibly caused by habitat loss. The role played by climatic events at the beginning of the Holocene and of the availability of reproductive habitats in the islands upon species loss is discussed. Furthermore, it is discussed how these results can help to guide conservation strategies of anuran species.
BITTENCOURT-SILVA, Gabriela Bueno. Comunidades de Anf?bios Anuros Insulares do Litoral Sudeste do Brasil: Composi??o Taxon?mica e Rela??es com a Hist?ria de Forma??o das Ilhas. 2011. 72p. Disserta??o (Mestrado em Biologia Animal). Instituto de Biologia, Departamento de Biologia Animal, Universidade Federal Rural do Rio de Janeiro, Serop?dica, RJ, 2011. Atrav?s de invent?rios e compila??o de dados da literatura levantou-se a composi??o de esp?cies de anf?bios anuros de oito ilhas, sendo seis da Costa Verde do Estado do Rio de Janeiro e duas do litoral norte do Estado de S?o Paulo. Al?m das ilhas, foram tamb?m compilados da literatura os invent?rios de duas comunidades representativas do litoral dos dois Estados. Adicionalmente, foram registradas 67 esp?cies, pertencentes a 11 fam?lias de anuros nas ilhas e 117 esp?cies e 14 fam?lias para o continente. O padr?o de distribui??o de riqueza das ilhas foi avaliado em rela??o ? ?rea das ilhas, ? composi??o de ambientes usados pelos anuros para reprodu??o e ? complexidade estrutural das ilhas. As an?lises de correla??o da riqueza de esp?cies vs. ?rea e riqueza de esp?cies vs. n?mero de ambientes reprodutivos apresentam resultados significativos, que s?o indicativos que a riqueza de esp?cies em ambientes fragmentados depende da intera??o de ambos os fatores. A fim de avaliar se as aus?ncias compartilhadas de esp?cies entre as ilhas ocorrem ao acaso ou encontram-se estruturadas, realizou-se uma an?lise de aninhamento com o aux?lio da m?trica NODF. O padr?o previsto foi confirmado e a perda de diversidade ? discutida em rela??o ? eventos clim?ticos do in?cio do Holoceno e ? disponibilidade de ambientes reprodutivos nas ilhas. Discute-se ainda como os resultados desse estudo podem servir para orientar programas de conserva??o de esp?cies de anf?bios anuros

At a meeting of worl leaders at the United Nations Conference on Environment and Development in Rio de Janeiro in 1992, it was recognized that because of the tremendous increase in the size of the global populations (which now is estimated to exceed six billion), there were concerns that global biodiversity was at risk if insufficient land were not put aside for conservation within formal Protected Areas. The primary aim of this study was to compare investment in Protected Areas in relation to socio-economic conditions at global and regional levels.

In the present study, we investigated amphibian biodiversity of a south-eastern Alpine region, Trentino, considering the evolutionary and ecological processes acting at the different levels of biological diversity (i.e. genes, species, and ecosystems), within a systemic perspective. We chose a model organism, the common frog (Rana temporaria), as target species for investigating patterns of diversity at the genetic level. We investigated the past evolutionary history of Rana temporaria by means of a phylogeographic study, based on mtDNA data. We highlighted a complex scenario, with three different Pleistocene glacial refugia located in the southern slopes of the Alps, routes of post-glacial recolonization following irregular patterns and a contact zone among different evolutionary lineages in the eastern part of the region. Afterwards, we conducted a population and landscape genetics study, using microsatellite markers for evaluating patterns of current genetic variability and genetic structure in Rana temporaria populations. We detected a main barrier to gene flow, the Adige river valley, and different spatial patterns, for both genetic variability and fine-scale population structure, in the two sub-regions. Lastly, we studied the relationship between species diversity of amphibian communities and genetic diversity of the model species, Rana temporaria. We found a strong negative correlation, and we demonstrated that the recorded pattern was due to the opposite influence of environmental factors on the two levels of biological diversity. Our results show the importance of considering the different levels of biodiversity in conservation strategies, and suggest that species diversity cannot be universally used as proxy for genetic diversity in conservation planning.
Nel presente studio, abbiamo analizzato la biodiversità anfibia di una regione delle Alpi sud-orientali, il Trentino, considerando i processi evoluzionistici ed ecologici che agiscono ai vari livelli della diversità biologica, all’interno di una prospettiva sistemica. Abbiamo scelto un organismo modello, la rana di montagna (Rana temporaria), come specie target per lo studio dei pattern di diversità a livello genetico. Abbiamo analizzato la storia evolutiva passata di Rana temporaria per mezzo di uno studio filogeografico, basato su dati di DNA mitocondriale. Abbiamo messo in luce uno scenario complesso, con tre diversi rifugi glaciali Pleistocenici, situati ai margini meridionali delle Alpi, rotte di ricolonizzazione irregolari, e una zona di contatto tra diverse linee evolutive nella parte orientale della regione. In seguito, abbiamo condotto uno studio di genetica di popolazione e del paesaggio, utilizzando marcatori microsatelliti per valutare i pattern attuali di diversità genetica e struttura genetica nelle popolazioni di Rana temporaria. Abbiamo riscontrato un’importante barriera al flusso genico, corrispondente alla valle del fiume Adige, e diversi pattern spaziali, sia per la variabilità genetica che per la struttura di popolazioni a scala fine, nelle due sotto-regioni. Infine, abbiamo studiato le relazioni tra la diversità specifica delle comunità anfibie e la diversità genetica della specie modello, Rana temporaria. Abbiamo riscontrato una forte correlazione negativa, e dimostrato che tale pattern è dovuto all’influenza opposta dei fattori ambientali sui due livelli di diversità biologica. I nostri risultati mostrano l’importanza di considerare i diversi livelli di biodiversità nelle strategie conservazionistiche, e suggeriscono che la diversità specifica non può venir universalmente utilizzata come proxy della diversità genetica nella pianificazione conservazionistica.

Cette thèse a pour objectif d’identifier les trajectoires plurimillénaires des écosystèmes de Corse à basse et moyenne altitude sous la triple influence des forçages climatiques, eustatiques et anthropiques à travers l’étude des assemblages d’insectes fossiles et des données paléobotaniques disponibles ou nouvellement acquises. Cette approche multidisciplinaire a été appliquée sur trois séquences sédimentaires prélevées à l’étang du Greco sur l’île Cavallo, au marais de Cannuta et à la tourbière de Bagliettu.Les résultats obtenus révèlent des changements majeurs dans la structuration du couvert végétal. Des signes d’ouverture du paysage apparaissent sur Cavallo et à Cannuta dès 5500-5000 cal. BP. Ils coïncident avec des indices d’activités des sociétés insulaires, lesquelles s’intensifient après 3000 cal. BP et plus particulièrement depuis 1000 ans à Bagliettu. Notre étude suggère que la sensibilité et la réponse des zones humides littorales face à la remontée relative du niveau marin dépend du contexte géomorphologique. Sur l’île Cavallo où le relief est faible, la transgression marine induit une augmentation de la salinité dans l’étang du Greco vers 3700 cal. BP, qui provoque une chute irréversible de la diversité des coléoptères aquatiques et hygrophiles. Au marais de Cannuta, où l’érosion des versants a favorisé la progradation de la plaine alluviale, notre étude montre une diminution de l’influence marine après 5000 cal. BP et une diversification de cette même entomofaune à partir de 1200 cal. BP. À Bagliettu, nous avons démontré l’importance des changements hydro-morphologiques des rivières dans la dynamique des écosystèmes tourbeux attenants et de leur entomofaune
This thesis aims to define the multi-millennial trajectories of Corsican ecosystems under the climatic, eustatic and anthropic factors via the study of fossil insect assemblages and previous or new palaeobotanical data. This multidisciplinary approach was carried out at low and middle elevation on three sedimentary archives from the Greco pond on Cavallo Island, the Cannuta marsh and the Bagliettu peat-bog. The results reveal major changes in the structure of the vegetation cover over the last 7000 years. Signs of more open landscapes occurred on Cavallo and in Cannuta from 5500-5000 cal. BP. They coincide with bio-markers of insular societies activities, which increased from 3000 cal. BP onward and more particularly during the last 1000 years at Bagliettu.This study also suggests that the sensitivity and the response of coastal wetlands to the relative sea-level rise depend on the geomorphological context. On the low-lying Cavallo Island, marine transgression induced an increase of salt conditions in the Greco pond from 3700 cal. BP, which in turn, caused an irreversible loss of aquatic and hygrophilous beetle diversity. In Cannuta marsh, erosion on catchment slopes favoured the progradation of the coastal floodplain and the results reveal a progressive decrease of the marine influence from 5000 cal. BP as well as a diversification of this entomofauna over the last 1200 years. In Bagliettu, the results show how hydro-morphological changes of the rivers impact the dynamics of adjacent peaty ecosystems and beetle diversity

The main objective of this work has been to determine the structure of the macroinvertebrate communities in mediterranean rivers at different scales, organization and taxonomical levels. To achieve that, an appropriated sampling methodology for macroinvertebrate studies has been developed. Physical and chemical data and riparian and habitat characteristics have been also recorded in each sampling site.

At regional scale it has been studied the macroinvertebrate composition at family level in all mediterranean regions around the world: California, Mediterranean Basin, Chile, South Africa and South and South-western Australia. Convergences and divergences between regions have been established pointing out the influence of the historical and ecological factors.

At local scale the effect of the temporality (differences between permanent and temporary rivers) and habitat (differences between riffles and pools) over the macroinvertebrate community in mediterranean rivers of the world have been studied. The results demonstrate a degree the convergence in the responses to temporality and habitat, being this last factor more convergent that the former. Moreover, the effects of the temporality over habitat and vice versa have been analyzed, indicating that both are strong correlated: temporality change the habitat and habitat influence over the temporality of the reach. Both aspects have an important effect over the macroinvertebrate community at different levels of observations from richness or composition to biological traits.

Moreover, at a lower taxonomical level, caddisfly community from Spanish mediterranean rivers has been studied. A total of 91 species have been identified using larvae, pupae and adults. The distribution patters displayed by these organisms indicate that historical factors may be important for some species, although most of them have a distribution limited by ecological variables. In that sense, ecological factors associated to large (basin) or small (reach or habitat) scale are important in the caddisfly distribution. Finally, because the importance of the caddisfly as bioindicators, optimums and tolerances to several chemical variables have been obtained for all species. Moreover, a study of the effect of the pollution over the fluctuating asymmetry of Hydropscyhe exocellata populations have demonstrated that at this level, there is a strong relatio.

Epiphytes are organisms attached to plants and are responsible for the majority of primary productivity in many aquatic systems. While epiphytes serve as a valuable food resource to herbivores, they may prove deleterious to the host plant by competing for light and nutrients, as well as increasing sheer stress. This study evaluated the impacts of nutrient additions, nitrogen and phosphorus, on the epiphytic algal community on Spartina alterniflora over the course of two growing seasons. Three nutrient treatments (N, P, and N+P) and one control treatment were placed in a salt marsh in the Tolomato River during the growing seasons of 2011 and 2012. To assess community development, we examined biomass, ash-free dry mass (AFDM), chlorophyll-a levels, cell counts, and community diversity by algal division. The nutrient additions did not significantly alter any of the measured parameters in either sampling year. However, the sampling month did have a significant (pa, and community composition. A total of 155 infrageneric taxa were identified. Biomass tended to be dominated by diatoms and red algae, while cyanobacteria were most abundant. In both years, biomass was highest in the spring with a second smaller pulse in the fall. Conversely, chlorophyll-a levels varied between the years and did not show the same monthly patterns as AFDM. A laboratory study subjecting S. alterniflora to the same nutrient additions also found no significant effects of increased nutrients, but did observe temporal changes in biomass and chlorophyll-a levels. Overall, epiphytic growth was not influenced by nutrient additions in this study suggesting that this and other similar salt marsh systems may be resilient to anthropogenic eutrophication. Instead, other factors, such as light and herbivory, likely played a key role in determining epiphytic algal growth and community composition.

Climatic models predict higher fluxes of UV-B radiation and a decrease in summer precipitation in the near future for the Mediterranean region. The UV radiation can be an oxidative stress factor for plants affecting their physiological activity and morphology. In this context, we aim to investigate the effects of UV (as UV-A as UV-B) radiation on Mediterranean woody species and its interaction with low water availability. The results showed that UV-A supplementation caused an increase in the plant biomass of some species when plants were grown under a low water supply. This beneficial effect on plant biomass seemed to be mediated by an improvement of plant water relations. Increases in leaf sclerophylly or leaf thickness, depending on the experiment, in response to enhanced UV radiation might have contributed to the amelioration of plant water deficit
Durant les properes dècades, a la Regió Mediterrània es preveu un augment de la radiació ultraviolada UV-B i una disminució en la precipitació. La radiació UV pot ser un factor oxidatiu per les plantes afectant la seva activitat fisiològica i la seva morfologia. En aquest context pretenem investigar els efectes de la radiació UV (tant UV-A com UV-B) sobre les espècies llenyoses mediterrànies així com la seva interacció amb una baixa disponibilitat hídrica. Els nostres resultats mostren que l’augment dels nivells d’UV-A pot incrementar la producció de biomassa quan les plantes creixen sota condicions de baixa disponibilitat hídrica. Aquest efecte beneficiós podria ser degut a una millora de les relacions hídriques. Els canvis en la morfologia foliar observats en resposta a la radiació UV (fulles més gruixudes o amb un major índex de massa per àrea depenent de l’experiment) poden haver contribuït a aquesta millora de les relacions hídriques

La conservation au niveau population est extrêmement nécessaire pour limiter la perte de biodiversité au sein d'une espèce ou d'un complexe d'espèces. Ainsi, l'évaluation de la variabilité inter-populationnelle dans le complexe est reconnue comme première étape importante pour bien définir les plans de conservation des espèces menacées. Arenaria grandiflora form un complexe d'espèces herbacées pérennes à courte durée de vie (4 ans en moyenne) menacé dans certains sites de ses zones de distribution en Europe. A ce jour, sa taxonomie n'est pas bien résolue, ce qui entraîne des problèmes potentiels pour mettre en oeuvre une conservation efficace de ce taxon. Une variation inter-populationnelle du complexe d'espèces A. grandiflora est présentée dans cette étude aux niveaux génétiques, cytogénétiques et morphométriques. Quatre méthodes ont été utilisées : des marqueurs microsatellites nucléaires, une approche cytogénétique, la cytométrie en flux, et enfin la morphométrie sur les feuilles. De plus, les études phénotypiques de variation de taux de germination entre stocks de graines ont été développées. Une différenciation significative entre les profils de variations moléculaires, cytogénétiques et phénotypiques a été détectée dans le complexe d'espèces. Deux cytotypes (diploïdes 2n=2x=22 et tétraploïdes 2n = 4x = 44) ont été mis en évidence en utilisant à la fois des méthodes classiques et des méthodes plus récentes (marqueurs microsatellites, nombres chromosomiques et cytométrie de flux). Le complexe d'espèces d'A; grandiflora présente une forte variation de la valeur de l'ADN 2C, la taille du génome varie de 2.11 ± 0.74 pg à 2.70 ± 0.11 pg pour les populations diploïdes et de 4.30 ± 1.51 pg à 5.27 ± 0.14 pg pour les populations de tétraploïdes. En outre, les grains de tétraploïdes germent significativement mieux que les graines des diploïdes. Les feuilles diffèrent considérablement entre les diploïdes (aciculaires et linéaires) et les tétraploïdes (lancéolées). Cette étude peut être considérée comme préliminaire pour une révision taxonomique de ce complexe d'espèces. D'autre part, grâce à l'ensemble des résultats obtenus, il est également possible de revisiter le concept d'unités évolutives significatives (ESUs) dans le complexe d'espèces A. grandiflora et donc de définir les groupes de populations devant faire l'objet de mesures distinctes. Ainsi, il est possible d'évaluer la pertinence de plans déjà entrepris et de proposer de nouveaux plans de restauration efficaces pour l'avenir de ce complexe d'espèces
Population-level conservation is being extremely required to restrain the biodiversity loss within a species. So, the assessment of the variability within the species complex is being renowned as an important first step to well implement the future conservation settings for threatened species. The species complex of Arenaria grandiflora is a short-lived perennial herbaceous and a threatened taxon in certain of sites of its distribution areas in Europe, with unresolved gentics and taxonomy, which lead to potential problems in the conservation and utilization of the resource. A differenciation among populations of the species complex of A. grandiflora is presented in this study based on the genetic, cytogenetic and phenotypic patterns. Intraspecific ploidy level varaition is an important aspect of numerous species, so, the present study explores this phenomenon within the A. grandiflora species complex in some type of populations (27 natural populations). To infer the intraspecific genetic and cytogenetic patterns of variability among the studied natural populations of the investigated species complex (A. grandiflora), three methods were used : nuclear microsatellite markers, cytogenetic and flow cytometry approaches. Moreover, the phenotypic patterns of variation among both the stock of seeds and the herbarium materials of A. grandiflora were defined. These patterns were detected using three methods of seed germination (in vitro culture, filter papers and potting soil) and morphometric approaches. A significant differentiation among populations' patterns of molecular, cytogenetic and phenotypic variation was detected within the A. grandiflora species complex. Presence of two closely related cytotypes (diploids 2n=2x=22 and tetraploids 2n=4x=44) was detected using both classical and more recent methods (chromosome number count and flow cytometry respectively). The species complex of A. grandiflora exhibits high variation in 2C-DNA value, the genome size ranges from 2.11 ± 0.74 pg to 2.70 ± 0.11 pg for the diploid populations and from 4.30 ± 1.51 pg to 5.27 ± 0.14 pg for the tetraploid populations. Moreover, the seeds of tetraploids germinate well and in high proportion than the seeds of the diploid ones. In addition, both acicular and linear leaves from the diploid populations differ significantly within the diploids and with the lanceolate leaves of the tetraploid ones. New protocol of seed germination for the tetraploids by in vitro culture after scarifying was described for th first time. The affected factors on seed germination percentages were determinated by an explanatory model of six predictors (altitude, longitude, latitude, ploidy levls, both period and condition of seed storage). Consequently, all these findings are fundamental for the determination of the evolutionarily significant units (ESUs) within A. grandiflora species complex and thus the definition of efficient restoration plans in the future. This study would consider as the preliminary signal for necessary revision for the intraspecific taxonomic keys problematic for this species complex

In the tropics, widespread deforestation and conversion of primary forests to agricultural and pasture lands has resulted in losses of composition, structure, and functions of forest landscapes. Deforestation in the tropics is typically preformed via slash-and-burn practices; the byproducts from combustion have been identified as the second-highest form of anthropogenically derived 'greenhouse-gases' (such as carbon dioxide) to the atmosphere, and have been linked to the warming of the earth. Landscape-scale measures of species composition and biomass structure of primary forests are important for two reasons: (i) they provide accurate, land-based measures to predict what has been lost due to land-uses, and (ii) they aid in the discovery of key factors which explain patterns in compositional and structural diversity that are useful for defining conservation objectives. In this thesis, I enumerate the landscape-level patterns in species composition and biomass and C structure for 20-0.79 ha primary tropical forest stands within the region of "Los Tuxtlas", Veracruz, Mexico. These 20 sites were selected to capture the variability in composition and structure with respect to an array of environmental variables. These variables included a wide elevational range (15-1280 m.a.s.l.), variable slopes (Range: 3-41% slope), 3 soil-types (ash derived, lava flows, and weathered soils), a gradient of mean annual temperatures (~19.5-25.7��C), a broad precipitation range (2500 - 4000 mm year�����), a rainfall frequency range (i.e. max rainfall in 24 hours; ranged 30->100 mm day�����), and 3 Holdridge Life Zones (Tropical Moist Forest, Subtropical Wet Forest, and Subtropical Lower Montane Rain Forest). Species composition was highly correlated with the environmental variables, particularly elevation. In general for plants ���10 cm dbh, site species richness declined at a rate of ~2 species per 100 m rise in elevation. Forest sites located at similar elevations were most similar in their species compositions as compared with sites separated by large elevational differences. Despite the gradual change in species richness and composition, four sub-regions, or forest environments, within Los Tuxtlas were identified that had different species compositions and distinct combinations of elevation, soil-types, and climates. These four sub-regions were described as community-types according to their geographic location: Lowland-Reserve (LR), La Perla Plateau (LP), Volcanic Upslope (VU), and Cloud Forests (CF). The LR, LP, and VU community-types were coarsely described as Tropical Evergreen Forests (TEF's; INEGI 2001). All community-types corresponded with classifications within the Holdridge Life Zone System; the LR community-type was classified as Tropical (transition to Subtropical) Moist Forest; LP and VU community-types were classified as Subtropical Wet Forest, and the Cloud Forest community-type was classified as Subtropical Lower Montane Rain Forest. These community-types and Life Zones are useful tools for conservation, as they represent unique forests that collectively capture much of the variation in the species richness and compositional diversity of the Los Tuxtlas region. Unlike species composition, the variability in forest structure among the 18 TEF sites was not associated with the environmental variables of the Los Tuxtlas landscape. On average, TEF's had a total aboveground biomass (TAGB) of 422 �� 17 Mg ha����� and 205 �� 8 Mg ha����� total aboveground carbon (C). The TAGB and C pools for Cloud Forests was ~18% lower than TEF's, and averaged 346 �� 1 and 168 �� 1 Mg ha�����, respectively. The majority of this biomass difference was due to large trees within the forest structure. Cloud Forests had generally fewer trees ���70 cm dbh, and a more even distribution of trees 30-70 cm dbh than TEF's. The biomass contribution of large trees (���70 cm dbh) accounted for most, if not all, of the variation in TAGB and C for these tropical forests. The relatively high TAGB and C pools implicates Los Tuxtlas forests as a significant pool of aboveground biomass and C within the Neotropics.
Graduation date: 2002

Tese de doutoramento em Biociências, na especialidade de Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Os ecossistemas naturais são formados por diversos conjuntos de espécies que interagem permanentemente umas com as outras para sobreviver e se reproduzir. Estes ecossistemas fornecem ao homem diversos serviços essenciais. Contudo, devido ao crescimento da população humana e a sua consequente necessidade por espaço e matérias-primas, o homem tem modificado o espaço que o rodeia ao longo do tempo. Estas alterações causadas em muitos ecossistemas têm afetado fortemente a biodiversidade, ameaçando a sua persistência ao longo do tempo e a sua capacidade em fornecer serviços do ecossistema essenciais. Têm sido desenvolvidos esforços para travar a perda de biodiversidade, manter o bem-estar e a sustentabilidade do crescimento do homem, muitas vezes com sucesso reduzido. Para compreender inteiramente os impactos das alterações ambientais na persistência a longo-termo dos ecossistemas é fundamental avaliar explicitamente os impactos em diferentes taxa e nas interações biológicas. Esta tese explora o impacto antropogénico das alterações do uso de solo sobre toda a comunidade biológica e expande o conhecimento existente sobre as interações entre aves, plantas e fungos. Esta tese é constituída por quatro capítulos. No primeiro capítulo estudei o impacto das novas, i.e. antropogénicos, florestas na diversidade de árvores, arbustos, herbáceas, macrofungos, artrópodes terrestres, artrópodes voadores noturnos, repteis, aves, pequenos mamíferos terrestres, carnívoros e morcegos. A abundância, riqueza específica, e composição da comunidade destes grupos foram comparados entre bosques nativos de carvalhos Quercus spp., plantações de pinheiro nativo Pinus pinaster, plantações da espécie exótica Eucalyptus globulus e bosques da espécie invasora Acacia dealbata. Para a maioria dos grupos a abundância e riqueza específica foram significativamente maiores nos bosques nativos, seguidos das plantações de pinheiro e finalmente dos bosques de espécies exóticas. A composição da comunidade diferiu entre todos os bosques, com os pinhais sendo os mais parecidos com os bosques nativos. Os diferentes grupos estudados apresentaram respostas distintas aos diferentes tipos de bosque. Os artrópodes terrestres foram semelhantes entre todos os bosques, enquanto árvores, arbustos, herbáceas e aves foram os grupos mais afetados pelas alterações do habitat. No segundo capítulo efetuei uma revisão bibliográfica, recolhendo toda a informação sobre visitas de flores por aves na Europa. Os mutualismos entre famílias de aves não especializadas e flores têm sido amplamente negligenciados. Eu encontrei registos de pelo menos 45 espécies de aves a visitar 95 espécies de plantas na Europa. As flores mais visitadas pertencem aos géneros Brassica sp., Citrus sp. e Eucalyptus sp. sendo visitados principalmente por felosas dos géneros Sylvia sp. e Phylloscopus sp. e chapins, principalmente o chapim-azul Cyanistes caeruleus. As aves parecem visitar mais frequentemente as flores durante o inverno e a primavera, e especialmente na bacia do Mediterrâneo, sugerindo que as aves podem ter um papel pertinente na dispersão do pólen a longa distância. No terceiro capítulo construí uma rede ecológica empírica que quantifica o transporte de pólen por aves numa floresta nativa no centro de Portugal. Este trabalho não só confirmou empiricamente a maioria dos resultados do capítulo anterior, mas demostrou também pela primeira vez, num continente, uma libertação ecológica, i.e. o aumento do nicho trófico de uma guilda inteira para incluir recursos pouco explorados do ambiente, enquanto anteriormente isto apenas era conhecido em ilhas oceânicas. A libertação ecológica aparenta ser menos intensa na Europa do que nas ilhas oceânicas provavelmente devido à maior diversidade biológica dos continentes. A rede ecológica deste capítulo apresenta muitas propriedades semelhantes a outras redes de ave-flor incluindo redes de famílias de aves nectarívoras especializadas. No quarto capítulo abordei a co-dispersão de esporos de fungos por aves que visitam flores em duas florestas em Portugal. As acumulações de pólen encontradas nas aves contêm frequentemente esporos de fungos. A ocorrência dos esporos de fungos nas acumulações de pólen das aves está fortemente associada à quantidade de pólen, sugerindo que as aves adquirem os dois propágulos em simultâneo. Foi demonstrado que as aves que visitam flores transportam ativamente os esporos de fungos entre flores, numa dispersão direta dos esporos, i.e. para locais especificamente adequados para o seu desenvolvimento (flores). Esta interação permaneceu praticamente desconhecida até agora. A presente tese aumentou o conhecimento existente sobre a biodiversidade nas florestas Europeias e como esta é negativamente afetada pelas modificações antropogénicas associadas à plantação e expansão de novas espécies florestais. Uma revisão bibliográfica e dados empíricos e originais confirmaram que o transporte de pólen por aves nectarívoras não especializadas é um fenómeno comum na Europa, refletindo um libertação ecológica de aves generalistas que utilizam recursos florais pouco explorados. Muitas das aves que visitam flores agem como co-dispersores de esporos de fungos entre flores. Esta tese demonstra a importância de não estudar cada táxon isoladamente, porque apenas estudando vários taxa e as suas interações numa abordagem ao nível da comunidade é possível uma melhor compreensão dos ecossistemas. Curiosamente, muitas das interações detetadas entre aves e plantas envolveram plantas exóticas, que formam atualmente ecossistemas florestais novos na Europa. Estas novas interações serão importantes na formação e re-estruturação destes novos ecossistemas florestais europeus.
Natural ecosystems are formed by diverse species assemblages permanently interacting with each other to survive and reproduce. These ecosystems provide humans several essential services. However, due to human population growth and its consequent demand for space and raw materials, man has been changing their surroundings for a long time. These caused alterations in many ecosystems, heavily affecting their biodiversity and threatening their long-term persistence and capacity to provide essential ecosystem services. Efforts have been made to halt biodiversity loss and maintain human well-being and a sustainable human growth, often with meagre success. To understand entirely the impacts of environmental changes on long-term persistence of ecosystems is vital to evaluate explicitly their impact across the different taxa and on biological interactions. This thesis explores the impact of anthropogenic land-use changes on entire biological communities and expands the current knowledge about interactions between birds, plants and fungi. The thesis comprises four data chapters. In the first chapter, I explore the impact of novel, i.e. anthropogenic, forests on the diversity of trees, shrubs, herbs, macrofungi, ground arthropods, night-flying arthropods, reptiles, birds, small mammals, carnivores and bats. The abundance, species richness and community composition of these groups was compared between native oak Quercus spp. woodlands, plantations of the native pine Pinus pinaster, plantations of the exotic Eucalyptus globulus and woodlands of the invasive acacia Acacia dealbata. In most groups the abundance and species richness was significantly higher in native woodlands, followed by pine plantations and in exotic woodlands. Community composition differed between all woodlands, with pinewoods being the most similar to native woodlands. The different study groups presented distinct responses to the different woodland types. Ground arthropods were similar in all woodlands, while trees, shrubs, herbs and birds were the groups that were most affected by habitat transformation.In the second chapter, I performed a literature review assembling all available information on flower visitation by birds in Europe. The mutualisms between non-specialized nectarivorous bird families and flowers has been largely neglected. I found records of at least 45 bird species visiting 95 plant species in Europe. The most visited flowers belong to the genus Brassica sp., Citrus sp. and Eucalyptus sp., which were visited mainly by warblers of the genus Sylvia sp. and Phylloscopus sp. and tits, mainly the blue tit Cyanistes caeruleus. Birds seem to visit flowers more often during winter and spring, and mainly in the Mediterranean basin, suggesting that birds may have a relevant role in the long distance dispersal of pollen. In the third chapter, I reconstructed an empirical ecological network quantifying the pollen transport by birds in a native forest in central Portugal. This work not only empirically confirmed most of the results from the previous chapter, but also showed for the first time an ecological release, i.e. the broadening of the trophic niche of an entire guild to include underexplored resources in the environment, in a continent when it was only known from oceanic islands. The ecological release appears to be less pronounced in Europe than in oceanic islands likely due to the higher diversity of the continent. The ecological network of this chapter has many similar properties to other bird-flower networks including networks of specialized nectarivorous birds’ families. In the fourth chapter, I explored the co-dispersal of fungi spores by flower-visiting birds in two forests in central Portugal. The pollen accumulations found on birds often contained fungi spores. The occurrence of fungi spores in the birds’ pollen accumulations was strongly associated with the amount of pollen, suggesting that birds acquire the two propagules simultaneously. It was shown that birds that visit flowers actively transport fungi spores between flowers, in a direct dispersal of the spores, i.e. to particularly suitable recruitment sites (flowers). This interaction has been largely unnoticed until now. The current thesis increases the knowledge about the biodiversity of European forests and how they are negatively affected by anthropogenic changes associated with the plantation and expansion of new forest species. A literature review and original empirical data confirmed that pollen transport by non-specialized nectarivorous birds is a common and widespread phenomenon in Europe, reflecting an interaction release of generalist birds to explore underexplored flower resources. Many of these flower visiting birds act as direct co-dispersers of fungi spores between flowers. This thesis shows the importance of not studying single and isolated taxon, because by only studying several taxa and their interactions in a community level approach allows a better understanding of the ecosystems. Interestingly, many interactions detected between birds and plants were with exotic plant species brought to Europe and now forming novel forest ecosystems. Such novel interactions should be important in shaping and re-structuring these novel forest ecosystems throughout Europe.
MARE – Marine and Environmental Sciences Centre
CEF – Centre for Functional Ecology

碩士
國立臺灣大學
森林學研究所
90
The biodiversity is the most important issue and idea in the research of conservation work now yet the range that such concept includes is very wide that it causes problem with its application in the real environment. Birds are highly sensitive to the changes of the composition of their habitats that they are positioned at the higher ends of the ecological system; and since compared to the other species, they are easier to be sampled and perceived etc, they are a very good biological indicator for biodiversity research of a larger scale. This study is based on the database from Wild Bird Federation Taiwan, WBFT to analyze the quality of such database in each county as well as the distribution pattern of the bird diversity in terms of place, elevation and season etc., also discussing about the characteristics of the distribution of the protected birds as well as the distribution of the birds’ hotspots. The results show that the sample effort for most of the countys in the database of birds can reflect the current situation of the bird diversity in that county roughly, yet it is commonly found that there are more data at low-elevation counties yet less data in certain counties in the period from June to August. In each county, the bird diversity has a significantly positive correlation with the area of that county and the range of its elevation spread, but the diversity of the migratory birds has nothing significantly correlated. On the elevational gradient, the breeding bird in each county at elevation about 1000m ~ 2000m is of the highest diversity that it shows a hump-curve. As for seasonal gradient, the diversity of the breeding birds is of not much fluctuation yet the diversity of the migratory birds is lower in the period from June to August. From the analysis of hotspots, it is found that there are significant correlations among breeding bird, protected species and endemic species. Also the distribution of the protected species in Taiwan is significantly shown localized. The results acquired for the bird diversity of each county from this study can serve as the reference of bird protection planning and nature conservation zoning jobs for each county. Besides, although the database of Wild Bird Federation Taiwan, WBFT is of a somewhat deviated structure, yet which can mostly reflect the situation of the bird diversity that it can be one of the most important links for promoting Taiwan Biological Resources Inventory in the future.

One of the challenges faced by the United Nations in addressing global environmental issues is to find politically agreeable strategies that promote action at the national level. One approach is to designate observances, such as the 2010 International Year of Biodiversity (IYB). While the UN has used these international designations for several years, the results achieved from them are rarely examined, particularly at the national level. This research asked: How has the International Year of Biodiversity been used to initiate actions that protect biodiversity in Canada? It developed a case study, based on data collected from a documentation review, semi-structured interviews, and collaborative dialogues designed to further explore preliminary findings. Data were analysed qualitatively. Results converged around six findings, primarily around the Year's use as a communications tool. Ten recommendations aim to guide future uses of international designations in Canada as a tool to address global environmental issues.

No
The European Union (EU) is an evolving system of multi-level governance (MLG). For scholars of the EU, a critical question is which level of governance has the most decisive influence on the integration process? Some studies of EU regional policy claim that subnational actors, using channels of interest representation that bypass national officials, interact directly with EU policy-makers generating outcomes that are neither desired nor intended by national executives. This article examines the development of EU biodiversity policy over a thirty-year period (c. 1970-2000) and finds that environmental groups, who were generally marginalized at the national level in Britain, have learnt to use EU opportunities to outflank the government, resulting in policy outcomes that they would be unlikely to secure through national channels of representation. However, the evidence presented suggests that supranational actors were the major cause of these unintended consequences, not environmental groups.

Arundo donax is an invasive species that mostly impacts on sensitive riparian ecosystems. Arundo is also invasive in South Africa, though less is known about its ecology, biology, and impacts. Since California and the Western Cape of South AFrica have similar Mediterranean-type climates, we could assume that the impacts of Arundo on ecosystems in California are likely to be similar in the Western Cape, and that control methods used could be extrapolated for use in South Africa. This thesis attempted to determine what impact Arundo has on biodiversity at the community-ecosystem level.

Thesis (M.S.)--University of Wisconsin--Madison, 1998.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 233-240).

La biodiversité est la variété de la vie et elle peut être étudiée à différents niveaux (génétique, espèces, écosystèmes) et à différents échelles (spatiale et temporelle). Les dernières décennies ont montré que la biodiversité marine avait été gravement sous-estimée. Afin d'étudier les caractéristiques de la grande diversité des espèces marines et les processus sous-jacents de l'évolution de ces dernières, il est évident et nécessaire de connaître les espèces. Nous sommes aujourd'hui confrontés aux taux les plus élevés d'extinction depuis la constitution de la société humaine (« crise de la biodiversité ») et seule une fraction d'espèces a été officiellement décrite (1,9 millions sur 11 millions), en raison, entre autres, d'une pénurie de taxonomistes formés et disponibles pour cet immense travail. Tous ces facteurs ont conduit à la proposition d'outils moléculaires pour permettre et faciliter l'identification des espèces et notamment le barcode moléculaire (le code-barres d'ADN). Il s'agit de séquencer un fragment d'ADN du gène mitochondrial cytochrome c oxydase 1 (COI) qui constitue alors un outil rapide, précis et rentable pour identifier les espèces. Ainsi, chaque espèce peut être définie par une étiquette d'identification unique et permanente qui ne sera pas changée par une éventuelle modification taxonomique. Outre l'attribution d'échantillons inconnus à des espèces identifiées a priori, les données fournies par le code-barres d'ADN seront très utiles pour des études phylogéographiques comparatives entre taxons multiples, pour clarifier les relations phylogénétiques à différents niveaux taxonomiques et pour élaborer des patrons évolutifs et de spéciation entre les groupes d'organismes. Le Chapitre 1 présente une mise en contexte du code-barres d'ADN par une revue des études qui ont été publiées sur le sujet, notamment en ce qui concerne l'identification des espèces marines. Le Chapitre 2 élabore une bibliothèque pour les crustacés marins de l'estuaire et du golfe du St. Laurent. Toutes les données (taxonomie, informations sur l'échantillonnage, images, séquences d'ADN et chromatogrammes), sont stockées en ligne dans le Barcode of Life Data Systems (BOLD) et sont disponibles pour un usage général. Les spécimens utilisés sont conservés comme 'vouchers' dans des institutions publiques pour des vérifications futures. Les résultats ont montré la présence d'un amphipode invasif dans l'estuaire (mentionné précédemment dans les Grands Lacs et à Montréal, avec des effets sur la faune indigène d'amphipodes), et l'existence d'espèces cryptiques potentielles chez les amphipodes, mysidacés et décapodes. Le Chapitre 3 est axé sur l'utilisation des séquences COI fournies par le code-barres d'ADN comme un outil complémentaire pour la taxonomie et la phylogénie des amphipodes de la famille Talitridae dans l'Atlantique du Nord. En effet, la distribution et la diversité actuelle des espèces est le résultat de processus d'évolution et d'interaction avec l'environnement à l'échelle d'une région géographique. Les études phylogénétiques permettent d'appréhender cette problématique en élaborant des scenarios évolutifs des relations entre taxons. Les résultats montrent l'existence d'espèces cryptiques chez trois espèces morphologiques. En outre, les genres anciens ne semblent pas être monophylétiques, suggérant la nécessité d'une révision taxonomique chez cette famille. Le Chapitre 4 aborde le thème de la diversité génétique qui permet la persistance des populations et des espèces dans le temps en permettant une adaptation continue aux changements environnementaux. À de grandes échelles spatiales, la diversité intraspécifique peut être structurée en généalogies en fonction de la géographie, définissant alors des patrons phylogéographiques, qui peuvent coïncider ou pas avec les divisions biogéographiques. Les séquences COI générées par le code-barres d'ADN ont été utilisées pour déduire des patrons phylogéographiques chez une espèce d'amphipode avec une distribution amphi-Atlantique, Gammarus oceanicus. Cette espèce est très abondante et représente une partie importante des communautés intertidales et des réseaux trophiques côtiers. Les résultats ont montré une division profonde au sein de cette espèce avec deux groupes ayant une séparation latitudinale (la région tempérée du Canada Atlantique versus la région subarctique du Baie d'Hudson et l'Europe), indiquant la présence des deux espèces cryptiques potentielles. L'ensemble de ces travaux de recherche a montré que la biodiversité marine, notamment chez les crustacés marins de l'Atlantique du Nord, était sous-estimée. Des espèces cryptiques potentielles ont été trouvées chez huit espèces morphologiques, sachant que seulement les espèces les plus communes ont été échantillonnées pour cette étude. Le taux de diversité augmentera certainement avec l'ajout d'échantillonnes de différents taxons, de divers types d'habitat et de régions marines distinctes. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : biodiversité marine, code-barres d'ADN, identification des espèces, Crustacea, diversité cryptique, Atlantique du Nord

碩士
大仁科技大學
環境管理研究所
96
In this work we assess the heavy metal pollution levels in sediment of Dapeng Bay between wet and dry seasons by using the method constructed by Borovec, Herr, and Gray. Factor analysis was performed to explain the properties and variation of heavy metals. The result shows that the most important latent factor in Dapeng Bay and neighboring rivers is the anthropogenic activities influence factor. From contour maps of factor scores it shows spatial distribution of heavy metals. Furthermore, ecological indices and heavy metal bioconcentration of shell in Dapeng Bay was discussedto understand the status of pollution in sediment and shell of heavy metal. The result shows that the strong pollutants of heavy metals in Dapeng Bay and neighboring rivers were Cd and Pb. Meanwhile the pollution degree in dry season was higher than in wet seasons. And the main reasons that cause this pollution were influenced by drainage of artificial canals in wet season and influenced by artificial canals and tidal impact in dry season. Heavy metal bioconcentration factor was show that Perna viridis has higher BCF of Mn and Cu, Barbatia velata has higher BCF of Fe, Al, and Ni, Katelysia hiantina has higher BCF of Cd, Zn, Pb, and Cr. As the seawater exchange rate is insufficiently to eliminate pollutants ,the process only occurs through one pocket-shape hole. Therefore, the more pollutants accumulation had worsened the habitat. The results will be helpful in developing a methodology for use by the government in refining its management programmers.

Genome-wide neutral diversity levels are shaped by both positive and purifying selection on linked sites. In humans like most species, the relative importance of these types of selection in shaping patterns of neutral diversity remains an open question. We can infer their relative contribution from observed patterns of neutral diversity by using information about recombination rates and targets of natural selection. To this end, I fit a joint model of the effects of positive selection (selective sweeps) and purifying selection (background selection) to genetic polymorphism data from the 1000 Genomes Project. I show that a model of the effects of background selection provides a good fit to patterns in diversity data and that incorporating the effects of selective sweeps does not improve the fit. Using my approach, the effects of background selection explain up to 60% of the variation in neutral diversity levels on the 1Mb scale and account for patterns in the data for which positive selection via selective sweeps had been invoked as explanations. I find that over 80% of the selected regions affecting neutral diversity levels are located outside of exons and that phylogenetic conservation is the best predictor of the source of selection in these regions. My results show that the genome-wide effects of background selection are pervasive, with measurable reductions in neutral diversity throughout almost the entirety of the autosomes. I provide maps of the effects of background selection and software for making similar inferences, which should provide important tools for future research that relies on interpreting patterns in neutral diversity levels.