859 resultados para conservation and fungicide
Resumo:
Conservation and management measures for exploited fish species rely on our ability to monitor variations in population abundance. In the case of the eastern stock of Atlantic bluefin tuna (ABFT), recent changes in management policies have strongly affected the reliability of fishery-dependent indicators due to drastic changes in fishing season/area, fisheries selectivity and strategy. However, fishery-independent indices of abundance are rare for large pelagic fish, and obtaining them is often costly and labor intensive. Here, we show that scientific aerial surveys are an appropriate tool for monitoring juvenile bluefin tuna abundance in the Mediterranean. We present an abundance index based on 62 aerial surveys conducted since 2000, using 2 statistical approaches to deal with the sampling strategy: line and strip transects. Both approaches showed a significant increase in juvenile ABFT abundance in recent years, resulting from the recovery plan established in 2007. Nonetheless, the estimates from the line transect method appear to be more robust and stable. This study provides essential information for fisheries management. Expanding the spatial coverage to other nursery grounds would further increase the reliability and representativeness of this index.
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The WorldFish Center has been collaborating with its partners (AWF and WWF) in the Maringa-Lopori-Wamba (MLW) and the Lac Tele-Lac Ntomba (LTL) Landscapes to develop participatory monitoring systems for aquatic ecosystems. This requires rigorous data collection regarding fishing effort and catch, and the establishment of community partnerships; enabling WorldFish Center researchers to understand and counteract the institutional legacies of previous NGO interventions. In the MLW, fisherfolk livelihoods are severely limited due to their extreme isolation from markets and government services. However, fisherfolk have some experience dealing with natural resource conservation or extraction entities as well as humanitarian agencies. Their history has left them slightly skeptical but reasonably willing to collaborate with incoming NGOs. Around Lac Ntomba, fisherfolk have had more extensive interactions with conservation and humanitarian NGOs, but despite their proximity to the Congo River, they appear to have very limited access to distant markets. As past benefits from NGO activities have been captured by local village elites many fishers are highly skeptical and even antagonistic toward NGOs in general, and see little benefits from collaborating with each other or NGOs. Similarly to the MLW and Lac Ntomba, Lac Maï-Ndombe fisherfolk were disillusioned by past NGO activities. However, in this area levels of fish catch are greater than in the other watersheds, and many fishers make regular trips to major markets in Kinshasa, Kikwit and Tchikapa. Consequently, while there are significant divisions to be addressed in Lac Maï-Ndombe, fisherfolk in general are more interested in exploring options for improving livelihoods. In order to overcome these hurdles, the WorldFish Center has introduced an integrated research-extension approach in its interactions with these communities. The teams conducted demonstrations of technological innovations that could significantly improve on present post-harvest fish processing practices, in particular: a solar fish drying tent and a fish smoking barrel.
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Making use of sea, as a place for dumping of wastes and other materials from human activities wasn’t forbidden before creation of the convention on the prevention of marine pollution by dumping of wastes and other matters (London Convention). Therefore, industrial countries, without any specific consideration, were dumping their wastes into the world’s seas. Many years and before the beginning of rapid development of industry, the great self- purification of seas were preventing some of discharging problems. But gradually, the increase of industrial development activities, exceeded the production of wastes and other matters, and this led to the misuse of world’s seas and oceans as a dump site. One of the most important consequences of 1972 Stockholm World Conference was to focusing world attention on threats have jeopardized marine environment balance. World countries` leaders committed in Stockholm to begin protecting the environment. Finally, this movement at marine environment section led to the creation of London Convention in the same year. London Convention was concluded for cooperating between countries at December 29, 1972 to promote effective control of all marine environment polluting resources and to prevent marine pollution by dumping wastes and other matters. Then it was opened for signature to other countries. At last, after 15 states signature, this convention was entered in to force at August 30.1975. Ratification and execution of London Convention resulted in coordinated performance of countries in marine waste management. Common actions with supports and cooperation of different international, regional, governmental and non-governmental organizations and agencies prevent marine pollution by dumping of wastes and other matters. Due to the importance of wastes in our marine and coastal areas, investigation of the performance of London Convention can identify the lack of regulations and lack of regulation supports about marine pollution prevention by dumping of wastes and other matters in Iran. Considering this issue, proper protection of seas will be achieved. London Convention has been studied here to achieve intended purposes. In first chapter, generalities about marine environment, including the importance and necessity of marine environment protection, with the focus on some internal and international resources of environmental law accompanying with marine pollution and its recourses, and finally, due to the study theme, dumping of wastes and other matters at seas with its impacts have been investigated .In the section of international measures, a brief history of marine pollution and marine environment international law with international law framework, exclusively for controlling of wastes and other material discharge at seas and oceans has been reviewed. In second chapter, obligations, amendments, and annexes of London Convention have been investigated and classified. The obligations have been categorized in to legal obligations and technical and organizational obligations. In former section, subject ,purpose, territory, exceptions, rights and duties of parties, convention amendments,… and in latter, special requirements for wastes assessment, determination of pollutants` permissible limit, site selection and type of discharge selection, design principles for marine environment quality monitoring program, and discharge license issuance mechanism have been studied. In third chapter, due to the examination of convention performance in Iran, the internal law system for marine environment conservation and its pollution has been mentioned in detail. Considering this, two issues have been compared .firstly, convention obligations with regional treaties that Iran as a party to them and secondly, Iranian internal law there of .Finally, common and different aspects of these issues have been determined. At last, recommendations and strategies for convention enforcement and conformity of its obligations with internal regulations have been presented. Furthermore, translation of convention English text has been reviewed and its protocol has been translated.
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Most eukaryotic cell motility relies on plasma membrane protrusions, which depend on the actin cytoskeleton and its tight regulation. The SCAR/WAVE complex, a pentameric assembly comprising SCAR/WAVE, Nap1, CYFIP/Pir121, Abi and HSPC300, is a key driver of actin-based protrusions such as pseudopods. SCAR/WAVE is thought to activate the Arp2/3 complex, a crucial actin nucleator, after being itself activated by upstream signals such as active Rac1. Despite recent progress on the study of the SCAR/WAVE complex, its regulation is still incompletely understood, with Nap1’s role being particularly enigmatic. Upon screening for potential Nap1 binding partners in the social amoeba Dictyostelium discoideum – a well established model organism in the study of the actin cytoskeleton and cell motility – we found FAM49, a ~36 kDa protein of unknown function which is highly conserved in Metazoa (animals) and evolutionarily closer species such as D. discoideum. Interestingly, D. discoideum’s FAM49 and its homologs contain a DUF1394 domain, which is also predicted in CYFIP/Pir121 proteins and most likely involved in their direct binding to active Rac1, which in turn contributes to SCAR/WAVE’s activation. FAM49’s unknown role, apparent high degree of conservation and potential connections to SCAR/WAVE and Rac1 persuaded us to start investigating its function and biological relevance in D. discoideum, leading to the work presented in this thesis. Several pieces of our data collectively support a function for FAM49 in modulating the protrusive behaviour, and ultimately motility, of D. discoideum cells, as well as a regulatory link between FAM49 and Rac1. FAM49’s involvement in protrusion regulation was first hinted at by our observation that GFP-tagged FAM49 is enriched in pseudopods. The possibility of a link with Rac1 was then strengthened by two additional observations: first, pseudopodial GFP-FAM49 is substantially co-enriched with active Rac, both showing fairly comparable spatio-temporal accumulation dynamics; second, when dominant-active (G12V) Rac1 is expressed in cells, it triggers the recruitment and persistent accumulation of GFP-FAM49 at the plasma membrane, where both become highly co-enriched. We subsequently determined that fam49 KO cells differ from wild-type cells in the way they protrude and move, as assessed in under-agarose chemotaxis assays. In particular, our data indicate that fam49 KO cells tend to display a lower degree of global protrusive activity, their protrusions extend more slowly and are less discrete, and the cells end up moving at lower speeds and with higher directional persistence. This phenotype was substantially rescued by FAM49 re-expression. While re-expressing FAM49 in fam49 KO cells we generated putative FAM49 overexpressor cells; compared to wild-type cells, they displayed atypically thin pseudopods and what seemed to be an excessively dynamic, and perhaps less coordinated, protrusive behaviour. Additional data in our study suggest that pseudopods made by fam49 KO cells are still driven by SCAR/WAVE, which is clearly not being replaced by WASP (as is now known to be the case in D. discoideum cells lacking a functional SCAR/WAVE complex). Nonetheless, the peculiar dynamics of those pseudopods imply that SCAR/WAVE’s activity is regulated differently when FAM49 is lost, though it remains to be determined how. This thesis is the first report of a dedicated study on FAM49 and lays the foundation for future research on it.
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Policy and decision makers dealing with environmental conservation and land use planning often require identifying potential sites for contributing to minimize sediment flow reaching riverbeds. This is the case of reforestation initiatives, which can have sediment flow minimization among their objectives. This paper proposes an Integer Programming (IP) formulation and a Heuristic solution method for selecting a predefined number of locations to be reforested in order to minimize sediment load at a given outlet in a watershed. Although the core structure of both methods can be applied for different sorts of flow, the formulations are targeted to minimization of sediment delivery. The proposed approaches make use of a Single Flow Direction (SFD) raster map covering the watershed in order to construct a tree structure so that the outlet cell corresponds to the root node in the tree. The results obtained with both approaches are in agreement with expert assessments of erosion levels, slopes and distances to the riverbeds, which in turn allows concluding that this approach is suitable for minimizing sediment flow. Since the results obtained with the IP formulation are the same as the ones obtained with the Heuristic approach, an optimality proof is included in the present work. Taking into consideration that the heuristic requires much less computation time, this solution method is more suitable to be applied in large sized problems.
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The cercospora leaf spot, caused by Cercospora abelmoschi Ellis and Everhart, is quite common in okra culture. Therefore, this study aimed to evaluate the efficiency of aqueous extracts of neem ( Azadirachta indica A. Juss), citronella ( Cymbopogon nardus (L.) Rendle), eucalyptus ( Eucalyptus grandis L.), ecolife®, A. indica oil and fungicide cercobin 700 PM® in control of cercospora leaf spot on okra in greenhouse. The extracts and neem oil were tested in concentration 10%, the fungicide cercobin 700PM® in dose 2.5 g.l-1, applied 10 days after pathogen inoculation by leaf spray and the citric biomass extract ecolife® in concentration 5.0 ml.l-1, applied 10 days before pathogen inoculation. All treatments, except ecolife®, were effective in controlling cercospora leaf spot and may be recommended as alternatives in agroecological systems.
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Une préoccupation importante pour le patrimoine culturel universitaire vient de se développer en Europe depuis les années 1980. Dans ce riche patrimoine sont inclus les biens mobiliers de valeur historique, scientifico-technique, académique, documentaire, artistique, architecturale et urbaine. Le continent européen a développé durant ces dernières années des actions significatives qui comprennent la création d’organisations, de comités à caractère international, ainsi que la rédaction de recommandations et règlements au niveau européen et institutionnel. Plusieurs universités ont pris des initiatives dans le domaine de la conservation et de la valorisation. À Cuba, il existe un grand intérêt pour le patrimoine culturel de la nation. Malgré la situation économique difficile depuis plusieurs années, Cuba a réussi des bons résultats dans la gestion des centres historiques et des biens patrimoniaux de la nation. Cependant, la thématique liée au patrimoine universitaire est encore peu discutée sur le territoire national, malgré depuis 2010, des actions pour étudier ce patrimoine sont mis en oeuvre grâce aux initiatives des universités de la capitale cubaine. Notre étude de cas, l’Instituto Superior Politécnico José Antonio Echeverría, appartenant au campus CUJAE1, fondé en 1964, a produit un patrimoine culturel universitaire de valeur scientifique, artistique et documentaire qui le distingue des autres universités. Malheureusement, ils existent plusieurs problèmes qui affectent les biens culturels mobiliers de l’ISPJAE et son campus. À partir de la situation actuelle, nous proposons une méthodologie en faveur de la conservation et la valorisation de ses biens, basée sur l’étude des tendances actuelles dans les universités européennes et cubaines étudiées. Les actions proposées favoriseront aussi les biens immobiliers, en tenant compte qu’ils ont un fort lien avec ceux mobiliers; ABSTRACT: An important concern for the university cultural heritage has just developed in Europe since the 1980s. The real asses of historic, scientific-technical, academic, documentary, artistic, architectural values are included in these rich heritages. The European continent developed during the last years significant actions which include the creation of organizations, committees with international character, as well as the writing of recommendations and regulations at the European and institutional level. Several universities took initiatives in the fields of the preservation and the valuation. In Cuba, there is a big interest for the cultural heritage of the nation. In spite of the difficult economic situation for several years, Cuba made a success of good results in the management of the historic centers and the patrimonial asses of the nation. However, the subject related to the university heritage is again little discussed in the national territory in spite of since 2010, several actions to study this heritage are implemented, thanks to the initiatives of the universities of the Cuban capital. Our case of study, Instituto Superior Politécnico José Antonio Echeverría, belonging to the campus CUJAE, established in 1964, produced a university cultural heritage of the scientific, artistic and documentary value, which distinguishes it from other universities. Unfortunately, there are several problems, which affect the real cultural asses of the ISPJAE and its campus. From the current situation, we propose a methodology in favor of the preservation and the valuation of its properties, based on the study of the current trends in the studied European and Cuban universities. The proposed actions will also favor the real property, taking into account that they have a strong link with those movable cultural asses; RIASSUNTO: Una preoccupazione importante per il patrimonio culturale universitario inizia a svilupparsi in Europa dagli anni 1980. In questo ricco patrimonio sono inclusi i beni mobili di valore storico, scientifico-tenico, accademico, documentario, artistico, architettonico e urbano. Il continente europeo ha sviluppato durante questi ultimi anni delle azioni significative che comprendono la creazione di organizazioni, di comitati internazionali, così come la redazione di raccomandazioni e regolamenti a livello europeo e istituzionale. Molte università hanno intrapreso delle iniziative nella conservazione e nella valorizzazione. A Cuba esiste un grande interesse per il patrimonio culturale della nazione. Malgrado la difficile situazione economica da molti anni Cuba ha ottenuto dei buoni risultati nella gestione di centri storici e di beni patrimoniali del Paese. Comunque, la tematica relativa al patrimonio universitario è ancora poco discussa anche se dal 2010 siano messe in opera delle azioni per studiare questo patrimonio, grazie alle iniziative di alcune università della capitale cubana. Il nostro caso di studio, l’Instituto Superior Politécnico José Antonio Echeverría –ISPJAE-, appartenente al campus CUJAE fondato nel 1964, ha prodotto un patrimonio culturale universitario di valore scientifico, artistico e documentale che la distinguono delle altre università. Purtroppo, esistono molti problemi che influenzano i beni culturali mobili dell’ISPJAE e del suo campus. A partire della situazione attuale e facendo parte di questa ricerca, si propone una metodologia a favore della conservazione e della valorizzazione dei loro beni fondata sullo studio delle tendenze attuali in università europee e cubane. Alcune delle azioni proposte sono finalizzate e destinate anche ai beni immobili, tenendo conto che questi hanno un forte rapporto con i beni mobili.
Resumo:
Current procedures for flood risk estimation assume flood distributions are stationary over time, meaning annual maximum flood (AMF) series are not affected by climatic variation, land use/land cover (LULC) change, or management practices. Thus, changes in LULC and climate are generally not accounted for in policy and design related to flood risk/control, and historical flood events are deemed representative of future flood risk. These assumptions need to be re-evaluated, however, as climate change and anthropogenic activities have been observed to have large impacts on flood risk in many areas. In particular, understanding the effects of LULC change is essential to the study and understanding of global environmental change and the consequent hydrologic responses. The research presented herein provides possible causation for observed nonstationarity in AMF series with respect to changes in LULC, as well as a means to assess the degree to which future LULC change will impact flood risk. Four watersheds in the Midwest, Northeastern, and Central United States were studied to determine flood risk associated with historical and future projected LULC change. Historical single framed aerial images dating back to the mid-1950s were used along with Geographic Information Systems (GIS) and remote sensing models (SPRING and ERDAS) to create historical land use maps. The Forecasting Scenarios of Future Land Use Change (FORE-SCE) model was applied to generate future LULC maps annually from 2006 to 2100 for the conterminous U.S. based on the four IPCC-SRES future emission scenario conditions. These land use maps were input into previously calibrated Soil and Water Assessment Tool (SWAT) models for two case study watersheds. In order to isolate effects of LULC change, the only variable parameter was the Runoff Curve Number associated with the land use layer. All simulations were run with daily climate data from 1978-1999, consistent with the 'base' model which employed the 1992 NLCD to represent 'current' conditions. Output daily maximum flows were converted to instantaneous AMF series and were subsequently modeled using a Log-Pearson Type 3 (LP3) distribution to evaluate flood risk. Analysis of the progression of LULC change over the historic period and associated SWAT outputs revealed that AMF magnitudes tend to increase over time in response to increasing degrees of urbanization. This is consistent with positive trends in the AMF series identified in previous studies, although there are difficulties identifying correlations between LULC change and identified change points due to large time gaps in the generated historical LULC maps, mainly caused by unavailability of sufficient quality historic aerial imagery. Similarly, increases in the mean and median AMF magnitude were observed in response to future LULC change projections, with the tails of the distributions remaining reasonably constant. FORE-SCE scenario A2 was found to have the most dramatic impact on AMF series, consistent with more extreme projections of population growth, demands for growing energy sources, agricultural land, and urban expansion, while AMF outputs based on scenario B2 showed little changes for the future as the focus is on environmental conservation and regional solutions to environmental issues.
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Plant genomes are extremely complex. Myriad factors contribute to their evolution and organization, as well as to the expression and regulation of individual genes. Here we present investigations into several such factors and their influence on genome structure and gene expression: the arrangement of pairs of physically adjacent genes, retrotransposons closely associated with genes, and the effect of retrotransposons on gene pair evolution. All sequenced plant genomes contain a significant fraction of retrotransposons, including that of rice. We investigated the effects of retrotransposons within rice genes and within a 1 kb putative promoter region upstream of each gene. We found that approximately one-sixth of all rice genes are closely associated with retrotransposons. Insertions within a gene’s promoter region tend to block gene expression, while retrotransposons within genes promote the existence of alternative splicing forms. We also identified several other trends in retrotransposon insertion and its effects on gene expression. Several studies have previously noted a connection among genes between physical proximity and correlated expression profiles. To determine the degree to which this correlation depends on an exact physical arrangement, we studied the expression and interspecies conservation of convergent and divergent gene pairs in rice, Arabidopsis, and Populus trichocarpa. Correlated expression among gene pairs was quite common in all three species, yet conserved arrangement was rare. However, conservation of gene pair arrangement was significantly more common among pairs with strongly correlated expression levels. In order to uncover additional properties of gene pair conservation and rearrangement, we performed a comparative analysis of convergent, divergent, and tandem gene pairs in rice, sorghum, maize, and Brachypodium. We noted considerable differences between gene pair types and species. We also constructed a putative evolutionary history for each pair, which led to several interesting discoveries. To further elucidate the causes of gene pair conservation and rearrangement, we identified retrotransposon insertions in and near rice gene pairs. Retrotransposon-associated pairs are less likely to be conserved, although there are significant differences in the possible effect of different types and locations of retrotransposon insertions. The three types of gene pair also varied in their susceptibility to retrotransposon-associated evolutionary changes.
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This thesis investigates how seven communities in a subregion of the Sierra Norte of Oaxaca are conserving high forest cover in the absence of national protected areas. To conduct this study I relied on archival research and the review of community documents, focus group interviews and land use transects to explore historical and current land use. I found that communities have conserved 88.34% of the subregion as forest cover, or 58,596 hectares out of a total territory of 66,264 hectares. Analysis suggests that the communities have undergone a historical transition from more passive conservation to more active, conscious conservation particularly in the last decade. This thesis further contends that communities deserve additional financial compensation for this active conservation of globally important forests for biodiversity conservation and that exercises in systematic conservation planning ignore the reality that existing biodiversity conservation in the subregion is associated with community ownership.
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The Florida Everglades is a highly diverse socionatural landscape that historically spanned much of the south Florida peninsula. Today, the Florida Everglades is an iconic but highly contested conservation landscape. It is the site of one of the world’s largest publicly funded ecological restoration programs, estimated to cost over $8 billion (U.S. GAO 2007), and it is home to over two million acres of federally protected lands, including the Big Cypress National Preserve and Everglades National Park. However, local people’s values, practices and histories overlap and often conflict with the global and eco-centric values linked to Everglades environmental conservation efforts, sparking environmental conflict. My dissertation research examined the cultural politics of nature associated with two Everglades conservation and ecological restoration projects: 1) the creation and stewardship of the Big Cypress National Preserve, and 2) the Tamiami Trail project at the northern boundary of Everglades National Park. Using multiple research methods including ethnographic fieldwork, archival research, participant observation, surveys and semi-structured interviews, I documented how these two projects have shaped environmental claims-making strategies to Everglades nature on the part of environmental NGOs, the National Park Service and local white outdoorsmen. In particular, I examined the emergence of an oppositional white identity called the Gladesmen Culture. My findings include the following: 1) just as different forms of nature are historically produced, contingent and power-laden, so too are different claims to Everglades nature; 2) identity politics are an integral dimension of Everglades environmental conflicts; and 3) the Big Cypress region’s history and contemporary conflicts are shaped by the broader political economy of development in south Florida. My dissertation concluded that identity politics, class and property relations have played a key, although not always obvious, role in shaping Everglades history and environmental claims-making, and that they continue to influence contemporary Everglades environmental conflicts.
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Annual counts of migrating raptors at fixed observation points are a widespread practice, and changes in numbers counted over time, adjusted for survey effort, are commonly used as indices of trends in population size. Unmodeled year-to-year variation in detectability may introduce bias, reduce precision of trend estimates, and reduce power to detect trends. We conducted dependent double-observer surveys at the annual fall raptor migration count at Lucky Peak, Idaho, in 2009 and 2010 and applied Huggins closed-capture removal models and information-theoretic model selection to determine the relative importance of factors affecting detectability. The most parsimonious model included effects of observer team identity, distance, species, and day of the season. We then simulated 30 years of counts with heterogeneous individual detectability, a population decline (λ = 0.964), and unexplained random variation in the number of available birds. Imperfect detectability did not bias trend estimation, and increased the time required to achieve 80% power by less than 11%. Results suggested that availability is a greater source of variance in annual counts than detectability; thus, efforts to account for availability would improve the monitoring value of migration counts. According to our models, long-term trends in observer efficiency or migratory flight distance may introduce substantial bias to trend estimates. Estimating detectability with a novel count protocol like our double-observer method is just one potential means of controlling such effects. The traditional approach of modeling the effects of covariates and adjusting the index may also be effective if ancillary data is collected consistently.
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The Marine Park Prof. Luiz Saldanha, in the coast of Arrabida, is the first marine park in continental Portugal. This area is a Nature 2000 site and is considered to be a hotspot for European marine biodiversity. In 2005, the management plan of the park was implemented, ending several habitat menaces, thereby allowing an application to the LIFE-NATURE Programme. The LIFE-BIOMARES project aimed at the restoration and management of the biodiversity of the marine park through several actions. The restoration of the seagrass prairies that were completely destroyed by fishing activities and recreational boating, was one of the most challenging. It included the transplanting of seagrasses from donor populations and the germination of seagrass seeds for posterior plantation to maintain genetic diversity in the transplanted area. One of the most popular actions was the implementation of environmental friendly moorings to integrate recreational use of the area with environmental protection. Several dissemination and environmental education actions concerning the marine park and the project took place and contributed to the public increase of the park acceptance. The seabed habitats were mapped along the park and a surrounding area to 100 m depth in order to create a habitat cartography of the park and to help locate alternative fishing zones. Biodiversity assessments for macrofauna revealed seasonal variations and an effect of the protection status. Preliminary results are presented and show that the marine park regulations are having a positive effect on biodiversity conservation and sustainable fisheries, thereby showing that these kind of conservation projects are important to disseminate coastal conservation best practices. The Biomares project is a model project that can be followed in the implementation of marine reserves and the establishment of the Natura 2000 marine network.
Determining conservation priority areas for Palearctic passerine migrant birds in sub-Saharan Africa
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Migratory bird species breeding in the Palearctic and overwintering in sub-Saharan Africa face multiple conservation challenges. As a result, many of these species have declined in recent decades, some dramatically. We therefore used the best available database for the distribution of 68 passerine migrants in sub-Saharan Africa to determine priority regions for their conservation. After modeling each species’ distribution using BIOMOD software, we entered the resulting species distributions at a 1° × 1° grid resolution into MARXAN software. We then used several different selection procedures that varied the boundary length modifier, species penalty factor, and the inclusion of grid cells with high human footprint and with protected areas. While results differed between selection procedures, four main regions were regularly selected: (1) one centered on southern Mali; (2) one including Eritrea, central Sudan, and northern Ethiopia; (3) one encompassing southwestern Kenya and much of Tanzania and Uganda; and (4) one including much of Zimbabwe and southwestern Zambia. We recommend that these four regions become priority regions for research and conservation efforts for the bird species considered in this study.
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Species occurrence and abundance models are important tools that can be used in biodiversity conservation, and can be applied to predict or plan actions needed to mitigate the environmental impacts of hydropower dams. In this study our objectives were: (i) to model the occurrence and abundance of threatened plant species, (ii) to verify the relationship between predicted occurrence and true abundance, and (iii) to assess whether models based on abundance are more effective in predicting species occurrence than those based on presence–absence data. Individual representatives of nine species were counted within 388 randomly georeferenced plots (10 m × 50 m) around the Barra Grande hydropower dam reservoir in southern Brazil. We modelled their relationship with 15 environmental variables using both occurrence (Generalised Linear Models) and abundance data (Hurdle and Zero-Inflated models). Overall, occurrence models were more accurate than abundance models. For all species, observed abundance was significantly, although not strongly, correlated with the probability of occurrence. This correlation lost significance when zero-abundance (absence) sites were excluded from analysis, but only when this entailed a substantial drop in sample size. The same occurred when analysing relationships between abundance and probability of occurrence from previously published studies on a range of different species, suggesting that future studies could potentially use probability of occurrence as an approximate indicator of abundance when the latter is not possible to obtain. This possibility might, however, depend on life history traits of the species in question, with some traits favouring a relationship between occurrence and abundance. Reconstructing species abundance patterns from occurrence could be an important tool for conservation planning and the management of threatened species, allowing scientists to indicate the best areas for collection and reintroduction of plant germplasm or choose conservation areas most likely to maintain viable populations.