198 resultados para Guilds
Resumo:
Transects of a Remotely Operated Vehicle (ROV) providing sea-bed videos and photographs were carried out during POLARSTERN expedition ANT-XVII/3 focussing on the ecology of benthic assemblages on the Antarctic shelf in the South-Eastern Weddell Sea. The ROV-system sprint 103 was equiped with two video- and one still camera, lights, flash-lights, compass, and parallel lasers providing a scale in the images, a tether-management system (TMS), a winch, and the board units. All cameras used the same main lense and could be tilted. Videos were recorded in Betacam-format and (film-)slides were made by decision of the scientific pilot. The latter were mainly made under the aspect to improve the identification of organisms depicted in the videos because the still photographs have a much higher optical resolution than the videos. In the photographs species larger than 3 mm, in the videos larger than 1 cm are recognisable and countable. Under optimum conditions the transects were strait; the speed and direction of the ROV were determined by the drift of the ship in the coastal current, since both, the ship and the ROV were used as a drifting system; the option to operate the vehicle actively was only used to avoide obstacles and to reach at best a distance of only approximately 30 cm to the sea-floor. As a consequence the width of the photographs in the foreground is approximately 50 cm. Deviations from this strategy resulted mainly from difficult ice- and weather conditions but also from high current velocity and local up-welling close to the sea-bed. The sea-bed images provide insights into the general composition of key species, higher systematic groups and ecological guilds. Within interdisciplinary approaches distributions of assemblages can be attributed to environmental conditions such as bathymetry, sediment characteristics, water masses and current regimes. The images also contain valuable information on how benthic species are associated to each other. Along the transects, small- to intermediate-scaled disturbances, e.g. by grounding icebergs were analysed and further impact to the entire benthic system by local succession of recolonisation was studied. This information can be used for models predicting the impact of climate change to benthic life in the Southern Ocean. All these approaches contribute to a better understanding of the fiunctioning of the benthic system and related components of the entire Antarctic marine ecosystem. Despite their scientific value the imaging methods meet concerns about the protection of sensitive Antarctic benthic systems since they are non-invasive and they also provide valuable material for education and outreach purposes.
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Human use of the oceans is increasingly in conflict with conservation of endangered species. Methods for managing the spatial and temporal placement of industries such as military, fishing, transportation and offshore energy, have historically been post hoc; i.e. the time and place of human activity is often already determined before assessment of environmental impacts. In this dissertation, I build robust species distribution models in two case study areas, US Atlantic (Best et al. 2012) and British Columbia (Best et al. 2015), predicting presence and abundance respectively, from scientific surveys. These models are then applied to novel decision frameworks for preemptively suggesting optimal placement of human activities in space and time to minimize ecological impacts: siting for offshore wind energy development, and routing ships to minimize risk of striking whales. Both decision frameworks relate the tradeoff between conservation risk and industry profit with synchronized variable and map views as online spatial decision support systems.
For siting offshore wind energy development (OWED) in the U.S. Atlantic (chapter 4), bird density maps are combined across species with weights of OWED sensitivity to collision and displacement and 10 km2 sites are compared against OWED profitability based on average annual wind speed at 90m hub heights and distance to transmission grid. A spatial decision support system enables toggling between the map and tradeoff plot views by site. A selected site can be inspected for sensitivity to a cetaceans throughout the year, so as to capture months of the year which minimize episodic impacts of pre-operational activities such as seismic airgun surveying and pile driving.
Routing ships to avoid whale strikes (chapter 5) can be similarly viewed as a tradeoff, but is a different problem spatially. A cumulative cost surface is generated from density surface maps and conservation status of cetaceans, before applying as a resistance surface to calculate least-cost routes between start and end locations, i.e. ports and entrance locations to study areas. Varying a multiplier to the cost surface enables calculation of multiple routes with different costs to conservation of cetaceans versus cost to transportation industry, measured as distance. Similar to the siting chapter, a spatial decisions support system enables toggling between the map and tradeoff plot view of proposed routes. The user can also input arbitrary start and end locations to calculate the tradeoff on the fly.
Essential to the input of these decision frameworks are distributions of the species. The two preceding chapters comprise species distribution models from two case study areas, U.S. Atlantic (chapter 2) and British Columbia (chapter 3), predicting presence and density, respectively. Although density is preferred to estimate potential biological removal, per Marine Mammal Protection Act requirements in the U.S., all the necessary parameters, especially distance and angle of observation, are less readily available across publicly mined datasets.
In the case of predicting cetacean presence in the U.S. Atlantic (chapter 2), I extracted datasets from the online OBIS-SEAMAP geo-database, and integrated scientific surveys conducted by ship (n=36) and aircraft (n=16), weighting a Generalized Additive Model by minutes surveyed within space-time grid cells to harmonize effort between the two survey platforms. For each of 16 cetacean species guilds, I predicted the probability of occurrence from static environmental variables (water depth, distance to shore, distance to continental shelf break) and time-varying conditions (monthly sea-surface temperature). To generate maps of presence vs. absence, Receiver Operator Characteristic (ROC) curves were used to define the optimal threshold that minimizes false positive and false negative error rates. I integrated model outputs, including tables (species in guilds, input surveys) and plots (fit of environmental variables, ROC curve), into an online spatial decision support system, allowing for easy navigation of models by taxon, region, season, and data provider.
For predicting cetacean density within the inner waters of British Columbia (chapter 3), I calculated density from systematic, line-transect marine mammal surveys over multiple years and seasons (summer 2004, 2005, 2008, and spring/autumn 2007) conducted by Raincoast Conservation Foundation. Abundance estimates were calculated using two different methods: Conventional Distance Sampling (CDS) and Density Surface Modelling (DSM). CDS generates a single density estimate for each stratum, whereas DSM explicitly models spatial variation and offers potential for greater precision by incorporating environmental predictors. Although DSM yields a more relevant product for the purposes of marine spatial planning, CDS has proven to be useful in cases where there are fewer observations available for seasonal and inter-annual comparison, particularly for the scarcely observed elephant seal. Abundance estimates are provided on a stratum-specific basis. Steller sea lions and harbour seals are further differentiated by ‘hauled out’ and ‘in water’. This analysis updates previous estimates (Williams & Thomas 2007) by including additional years of effort, providing greater spatial precision with the DSM method over CDS, novel reporting for spring and autumn seasons (rather than summer alone), and providing new abundance estimates for Steller sea lion and northern elephant seal. In addition to providing a baseline of marine mammal abundance and distribution, against which future changes can be compared, this information offers the opportunity to assess the risks posed to marine mammals by existing and emerging threats, such as fisheries bycatch, ship strikes, and increased oil spill and ocean noise issues associated with increases of container ship and oil tanker traffic in British Columbia’s continental shelf waters.
Starting with marine animal observations at specific coordinates and times, I combine these data with environmental data, often satellite derived, to produce seascape predictions generalizable in space and time. These habitat-based models enable prediction of encounter rates and, in the case of density surface models, abundance that can then be applied to management scenarios. Specific human activities, OWED and shipping, are then compared within a tradeoff decision support framework, enabling interchangeable map and tradeoff plot views. These products make complex processes transparent for gaming conservation, industry and stakeholders towards optimal marine spatial management, fundamental to the tenets of marine spatial planning, ecosystem-based management and dynamic ocean management.
Resumo:
Habitat loss, fragmentation, and degradation threaten the World’s ecosystems and species. These, and other threats, will likely be exacerbated by climate change. Due to a limited budget for conservation, we are forced to prioritize a few areas over others. These places are selected based on their uniqueness and vulnerability. One of the most famous examples is the biodiversity hotspots: areas where large quantities of endemic species meet alarming rates of habitat loss. Most of these places are in the tropics, where species have smaller ranges, diversity is higher, and ecosystems are most threatened.
Species distributions are useful to understand ecological theory and evaluate extinction risk. Small-ranged species, or those endemic to one place, are more vulnerable to extinction than widely distributed species. However, current range maps often overestimate the distribution of species, including areas that are not within the suitable elevation or habitat for a species. Consequently, assessment of extinction risk using these maps could underestimate vulnerability.
In order to be effective in our quest to conserve the World’s most important places we must: 1) Translate global and national priorities into practical local actions, 2) Find synergies between biodiversity conservation and human welfare, 3) Evaluate the different dimensions of threats, in order to design effective conservation measures and prepare for future threats, and 4) Improve the methods used to evaluate species’ extinction risk and prioritize areas for conservation. The purpose of this dissertation is to address these points in Colombia and other global biodiversity hotspots.
In Chapter 2, I identified the global, strategic conservation priorities and then downscaled to practical local actions within the selected priorities in Colombia. I used existing range maps of 171 bird species to identify priority conservation areas that would protect the greatest number of species at risk in Colombia (endemic and small-ranged species). The Western Andes had the highest concentrations of such species—100 in total—but the lowest densities of national parks. I then adjusted the priorities for this region by refining these species ranges by selecting only areas of suitable elevation and remaining habitat. The estimated ranges of these species shrank by 18–100% after accounting for habitat and suitable elevation. Setting conservation priorities on the basis of currently available range maps excluded priority areas in the Western Andes and, by extension, likely elsewhere and for other taxa. By incorporating detailed maps of remaining natural habitats, I made practical recommendations for conservation actions. One recommendation was to restore forest connections to a patch of cloud forest about to become isolated from the main Andes.
For Chapter 3, I identified areas where bird conservation met ecosystem service protection in the Central Andes of Colombia. Inspired by the November 11th (2011) landslide event near Manizales, and the current poor results of Colombia’s Article 111 of Law 99 of 1993 as a conservation measure in this country, I set out to prioritize conservation and restoration areas where landslide prevention would complement bird conservation in the Central Andes. This area is one of the most biodiverse places on Earth, but also one of the most threatened. Using the case of the Rio Blanco Reserve, near Manizales, I identified areas for conservation where endemic and small-range bird diversity was high, and where landslide risk was also high. I further prioritized restoration areas by overlapping these conservation priorities with a forest cover map. Restoring forests in bare areas of high landslide risk and important bird diversity yields benefits for both biodiversity and people. I developed a simple landslide susceptibility model using slope, forest cover, aspect, and stream proximity. Using publicly available bird range maps, refined by elevation, I mapped concentrations of endemic and small-range bird species. I identified 1.54 km2 of potential restoration areas in the Rio Blanco Reserve, and 886 km2 in the Central Andes region. By prioritizing these areas, I facilitate the application of Article 111 which requires local and regional governments to invest in land purchases for the conservation of watersheds.
Chapter 4 dealt with elevational ranges of montane birds and the impact of lowland deforestation on their ranges in the Western Andes of Colombia, an important biodiversity hotspot. Using point counts and mist-nets, I surveyed six altitudinal transects spanning 2200 to 2800m. Three transects were forested from 2200 to 2800m, and three were partially deforested with forest cover only above 2400m. I compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analyzing the effect of deforestation on 134 species, I tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species’ elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species’ elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations.
In Chapter 5, I refine the ranges of 726 species from six biodiversity hotspots by suitable elevation and habitat. This set of 172 bird species for the Atlantic Forest, 138 for Central America, 100 for the Western Andes of Colombia, 57 for Madagascar, 102 for Sumatra, and 157 for Southeast Asia met the criteria for range size, endemism, threat, and forest use. Of these 586 species, the Red List deems 108 to be threatened: 15 critically endangered, 29 endangered, and 64 vulnerable. When ranges are refined by elevational limits and remaining forest cover, 10 of those critically endangered species have ranges < 100km2, but then so do 2 endangered species, seven vulnerable, and eight non-threatened ones. Similarly, 4 critically endangered species, 20 endangered, and 12 vulnerable species have refined ranges < 5000km2, but so do 66 non-threatened species. A striking 89% of these species I have classified in higher threat categories have <50% of their refined ranges inside protected areas. I find that for 43% of the species I assessed, refined range sizes fall within thresholds that typically have higher threat categories than their current assignments. I recommend these species for closer inspection by those who assess risk. These assessments are not only important on a species-by-species basis, but by combining distributions of threatened species, I create maps of conservation priorities. They differ significantly from those created from unrefined ranges.
Resumo:
Les organismes aquatiques sont adaptés à une grande variabilité hydrique et thermique des rivières. Malgré ceci, la régulation des eaux suscite des changements aux débits qui peuvent provoquer des impacts négatifs sur la biodiversité et les processus écologiques en rivière. Celle-ci peut aussi causer des modifications au niveau des régimes thermiques et des caractéristiques de l’habitat du poisson. Des données environnementales et biologiques décrivant l’habitat du poisson existent, mais elles sont incomplètes pour plusieurs rivières au Canada et de faible qualité, limitant les relations quantitatives débit-température-poissons à un petit nombre de rivières ou à une région étudiée. La recherche menée dans le cadre de mon doctorat concerne les impacts de la génération d'hydroélectricité sur les rivières; soit les changements aux régimes hydriques et thermiques reliés à la régulation des eaux sur la variation des communautés ichtyologiques qui habitent les rivières régulées et naturelles au Canada. Suite à une comparaison d’échantillonnage de pêche, une méthode constante pour obtenir des bons estimés de poisson (richesse, densité et biomasse des espèces) a été établie pour évaluer la structure de la communauté de poissons pour l’ensemble des rivières ciblées par l’étude. Afin de mieux comprendre ces changements environnementaux, les principales composantes décrivant ces régimes ont été identifiées et l’altération des régimes hydriques pour certaines rivières régulées a été quantifiée. Ces résultats ont servi à établir la relation significative entre le degré de changement biotique et le degré de changement hydrique pour illustrer les différences entre les régimes de régulation. Pour faire un complément aux indices biotiques déjà calculés pour l’ensemble des communautés de poissons (diversité, densité et biomasse des espèces par rivière), les différences au niveau des guildes de poissons ont été quantifiées pour expliquer les divers effets écologiques dus aux changements de régimes hydriques et thermiques provenant de la gestion des barrages. Ces derniers résultats servent à prédire pour quels traits écologiques ou groupes d’espèces de poissons les composantes hydriques et thermiques sont importantes. De plus, ces derniers résultats ont servi à mettre en valeur les variables décrivant les régimes thermiques qui ne sont pas toujours inclues dans les études hydro-écologiques. L’ensemble des résultats de cette thèse ont des retombées importantes sur la gestion des rivières en évaluant, de façon cohérente, l’impact de la régulation des rivières sur les communautés de poissons et en développant des outils de prévision pour la restauration des écosystèmes riverains.
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Insect pollination underpins apple production but the extent to which different pollinator guilds supply this service, particularly across different apple varieties, is unknown. Such information is essential if appropriate orchard management practices are to be targeted and proportional to the potential benefits pollinator species may provide. Here we use a novel combination of pollinator effectiveness assays (floral visit effectiveness), orchard field surveys (flower visitation rate) and pollinator dependence manipulations (pollinator exclusion experiments) to quantify the supply of pollination services provided by four different pollinator guilds to the production of four commercial varieties of apple. We show that not all pollinators are equally effective at pollinating apples, with hoverflies being less effective than solitary bees and bumblebees, and the relative abundance of different pollinator guilds visiting apple flowers of different varieties varies significantly. Based on this, the taxa specific economic benefits to UK apple production have been established. The contribution of insect pollinators to the economic output in all varieties was estimated to be £92.1M across the UK, with contributions varying widely across taxa: solitary bees (£51.4M), honeybees (£21.4M), bumblebees (£18.6M) and hoverflies (£0.7M). This research highlights the differences in the economic benefits of four insect pollinator guilds to four major apple varieties in the UK. This information is essential to underpin appropriate investment in pollination services management and provides a model that can be used in other entomolophilous crops to improve our understanding of crop pollination ecology.
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Understanding how biodiversity spatially distribute over both the short term and long term, and what factors are affecting the distribution, are critical for modeling the spatial pattern of biodiversity as well as for promoting effective conservation planning and practices. This dissertation aims to examine factors that influence short-term and long-term avian distribution from the geographical sciences perspective. The research develops landscape level habitat metrics to characterize forest height heterogeneity and examines their efficacies in modelling avian richness at the continental scale. Two types of novel vegetation-height-structured habitat metrics are created based on second order texture algorithms and the concepts of patch-based habitat metrics. I correlate the height-structured metrics with the richness of different forest guilds, and also examine their efficacies in multivariate richness models. The results suggest that height heterogeneity, beyond canopy height alone, supplements habitat characterization and richness models of two forest bird guilds. The metrics and models derived in this study demonstrate practical examples of utilizing three-dimensional vegetation data for improved characterization of spatial patterns in species richness. The second and the third projects focus on analyzing centroids of avian distributions, and testing hypotheses regarding the direction and speed of these shifts. I first showcase the usefulness of centroids analysis for characterizing the distribution changes of a few case study species. Applying the centroid method on 57 permanent resident bird species, I show that multi-directional distribution shifts occurred in large number of studied species. I also demonstrate, plain birds are not shifting their distribution faster than mountain birds, contrary to the prediction based on climate change velocity hypothesis. By modelling the abundance change rate at regional level, I show that extreme climate events and precipitation measures associate closely with some of the long-term distribution shifts. This dissertation improves our understanding on bird habitat characterization for species richness modelling, and expands our knowledge on how avian populations shifted their ranges in North America responding to changing environments in the past four decades. The results provide an important scientific foundation for more accurate predictive species distribution modeling in future.
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Artificial lakes must differ from natural lakes in important structural and functional aspects that need to be understood so that these ecosystems can be properly managed. The aim of this work was to test the hypothesis that the artificial lakes (impoundments) in the semi-arid region of the Rio Grande do Norte State are more eutrophic and turbid and have different trophic structure when compared to the natural coastal lakes that occur in the humid eastern coast of the State. To test this hypothesis, 10 natural lakes and 8 artificial lakes with about 100 ha were sampled between September and November 2005 for the determination of some limnological variables and the abundance of the main fish species, which were grouped in three trophic guilds: facultative piscivores, facultative planktivores and omnivores. The results show that the artificial lakes had significantly higher concentrations of total nitrogen, total phosphorus, chlorophyll a , total and volatile suspended solids than the natural lakes. Results also show that the values of pH, total alkalinity, electric conductivity, turbidity as well as the coefficient of vertical attenuation of light were significantly higher in the artificial lakes than in the natural lakes. In the artificial lakes, the abundance of facultative planktivores was significantly higher, while the abundance of facultative piscivores significantly lower than in the natural lakes. There was no significant difference in the abundance of omnivorous fish between the two types of lakes. These results suggest that the increase in turbidity together with the other changes in the water quality of the artificial lakes, modifies the trophic structure of the fish communities reducing the importance of piscivores and the length of the food chains
Resumo:
O objetivo desse estudo foi caracterizar a composição florística e a estrutura do componente arbóreo em fragmento de Floresta Ombrófila Mista Alto-Montana e avaliar a influência do efeito de borda sobre a organização, estrutura, riqueza e diversidade de espécies. Foram alocadas 50 parcelas permanentes de 10 x 20 m, divididas em cinco transeções distanciadas, no mínimo, 100 m entre si, em um fragmento florestal, no município de Bom Jardim da Serra - SC. As árvores com circunferência ≥ 15,7 cm na altura do peito (CAP) foram mensuradas (CAP e altura total), identificadas e classificadas quanto às guildas de regeneração (pioneiras, climácicas exigentes em luz e climácicas tolerantes à sombra). Os dados foram analisados por meio dos índices de valor de importância (IVI), NMDS (Nonmetric Multidimensional Scaling), modelo aditivo generalizado e regressões lineares simples. Foram observados 1.457 indivíduos arbóreos, distribuídos em 29 famílias, 43 gêneros e 55 espécies. A espécie com maior valor de importância foi Dicksonia sellowiana Hook. Não foi observada influência do efeito de borda sobre a organização, a estrutura (diâmetro médio, altura média e densidade) da comunidade e participação relativa das guildas de regeneração. No entanto, ficaram evidenciados maiores valores de diversidade, riqueza e equabilidade nas áreas de borda. Desta forma, concluí-se que parte das variações dos valores relativos à diversidade de espécies arbóreas na Floresta Ombrófila Mista Ato-Montana foi determinada pela distância da borda.
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O efeito das grandes barragens na comunidade piscícola vem sendo documentado por numerosos estudos, enquanto o número de trabalhos que incidem sobre o efeito dos obstáculos de pequena dimensão é bastante mais reduzido. A comunidade piscícola foi amostrada e as variáveis ambientais foram caracterizadas em 28 locais divididos por dois cursos de água da Península Ibérica, 14 dos quais localizados imediatamente a montante, jusante e entre cinco pequenos obstáculos na Ribeira de Muge e 14 na Ribeira de Erra, considerada a linha de água de referência. Através de análise estatística multivariada foi possível verificar que variáveis de habitat como a velocidade de corrente e a profundidade, e não as variáveis físico-químicas, foram as principais responsáveis pela discriminação dos vários grupos de locais nas duas ribeiras. A ribeira de referência exibiu um gradiente longitudinal de velocidade de corrente que, contudo, não era suficientemente forte para causar alterações significativas na composição e estrutura dos agrupamentos piscícolas. Através da sucessiva e drástica repetição deste gradiente junto a cada estrutura, a ribeira com obstáculos apresentou diferenças na fauna piscícola entre os três tipos de locais. Os troços lênticos a montante apresentavam uma densidade mais elevada de espécies limnofilicas, omnívoras e exóticas, como o góbio (Gobio lozanoi), que estão bem adaptadas a este tipo de habitat. Os locais de amostragem situados a jusante e entre os obstáculos caracterizavam-se pela dominância de taxa reófilos e invetivo-os (i.e. barbo, Luciobarbus bocagei). As métricas relacionadas com a riqueza específica não apresentaram diferenças entre os três tipos de locais, ao contrário da diversidade que foi mais elevada nos pontos situados entre os obstáculos, afastados da sua influência directa, onde a diversidade de habitats também é mais elevada. Contrariamente aos locais a montante, os troços a jusante e entre os obstáculos apresentaram similaridades, em muitas das características estudadas, com a ribeira de referência, sugerindo que este tipo de estruturas provoca uma alteração mais significativa na comunidade piscícola a montante. Este estudo sugere que os efeitos dos pequenos obstáculos no habitat e na ictiofauna são, em parte, semelhantes aos descritos para as grandes barragens, fornecendo considerações importantes para os esforços de conservação dos ecossistemas ribeirinhos. ABSTRACT; Many studies have assessed the effects of large dams on fishes but few have examined the effects of small obstacles. Fishes were sampled and environmental variables were characterized at 28 sites in two lberian streams, 14 located immediately downstream, upstream and between five small obstacles at River Muge and 14 at River Erra, considered as the reference stream. Multivariate analysis indicated that habitat variables like current velocity and depth, but not physicochemistry, were the main responsible for site groups' discrimination in both streams. The reference stream exhibited a longitudinal gradient of current velocity that, however, wasn't strong enough to cause significant changes in the fish assemblage's composition and structure. By successive and drastically repeating this gradient near each structure, the obstac1es stream presented differences in fish fauna between the three site types. Lentic upstream sites presented higher density of limnophilic, omnivorous and exotic species, like gudgeon Gobio lozanoi, who are well adapted to this type of habitat. Downstream and between obstacles sites were characterized by the dominance of rheophilic and invertivorous taxa, especially barbel Luciobarbus bocagei. Richness metrics did not differ among site types, but diversity was higher in sites located between the obstacles away from its direct influence, where the habitat diversity was higher. Contrarily to upstream sites, downstream and between obstacles sites were similar in many of the studied features to the reference stream, implying that this type of structures cause a higher modification in the upstream fish community. This study suggests that the effects of small obstacles on habitat and fishes are similar, in some extent, to those reported for larger dams, providing important considerations for riverine ecosystem conservation efforts.
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Conhecer os requisitos ambientais por parte das espécies demonstrou ser essencial em disciplinas como a ecologia e a biologia da conservação. O presente estudo visa estudar as respostas e dependência das comunidades de aves em relação às galerias ripícolas mediterrânicas. Para tal utilizaram-se dados recolhidos pelo River Habitat Survey (RHS) e por censos por pontos de escuta, em três ribeiras no sul de Portugal. Os dados ambientais foram estruturados em matrizes de acordo com as características físicas da ribeira e das margens, e modificações antropogénicas. Enquanto os dados biológicos foram agrupados em guildas: alimentação e ocupação vertical do habitat ("estrato"). Através de análises canónicas aos a dos estruturados obtiveram-se correlações válidas entre as matrizes ambientais e as guildas, nomeadamente para indivíduos directamente dependentes da água e planadores ("aéreas"), provando a validade da metodologia e o potencial da combinação destas duas técnicas. ABSTRACT; Understanding species habitat requirements has proved to be essential in ecology and conservation biology. The present report aims to examine the responses and dependence we used data collected by River Habitat Survey (RHS) and point count censuses in three rivers in southern Portugal. The environmental data were structured in matrices according to physical characteristics of the stream, the banks and anthropogenic modifications, whilst biological data was grouped into guilds: foraging and occupation ("estate"). Through canonical analysis to structured data we obtained valid correlations between the environmental variables and species guilds, particularly for those directly dependent on water and gliders ("aéreas"), proving the validity of the methodology and the potential of these two techniques working together.
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Les organismes aquatiques sont adaptés à une grande variabilité hydrique et thermique des rivières. Malgré ceci, la régulation des eaux suscite des changements aux débits qui peuvent provoquer des impacts négatifs sur la biodiversité et les processus écologiques en rivière. Celle-ci peut aussi causer des modifications au niveau des régimes thermiques et des caractéristiques de l’habitat du poisson. Des données environnementales et biologiques décrivant l’habitat du poisson existent, mais elles sont incomplètes pour plusieurs rivières au Canada et de faible qualité, limitant les relations quantitatives débit-température-poissons à un petit nombre de rivières ou à une région étudiée. La recherche menée dans le cadre de mon doctorat concerne les impacts de la génération d'hydroélectricité sur les rivières; soit les changements aux régimes hydriques et thermiques reliés à la régulation des eaux sur la variation des communautés ichtyologiques qui habitent les rivières régulées et naturelles au Canada. Suite à une comparaison d’échantillonnage de pêche, une méthode constante pour obtenir des bons estimés de poisson (richesse, densité et biomasse des espèces) a été établie pour évaluer la structure de la communauté de poissons pour l’ensemble des rivières ciblées par l’étude. Afin de mieux comprendre ces changements environnementaux, les principales composantes décrivant ces régimes ont été identifiées et l’altération des régimes hydriques pour certaines rivières régulées a été quantifiée. Ces résultats ont servi à établir la relation significative entre le degré de changement biotique et le degré de changement hydrique pour illustrer les différences entre les régimes de régulation. Pour faire un complément aux indices biotiques déjà calculés pour l’ensemble des communautés de poissons (diversité, densité et biomasse des espèces par rivière), les différences au niveau des guildes de poissons ont été quantifiées pour expliquer les divers effets écologiques dus aux changements de régimes hydriques et thermiques provenant de la gestion des barrages. Ces derniers résultats servent à prédire pour quels traits écologiques ou groupes d’espèces de poissons les composantes hydriques et thermiques sont importantes. De plus, ces derniers résultats ont servi à mettre en valeur les variables décrivant les régimes thermiques qui ne sont pas toujours inclues dans les études hydro-écologiques. L’ensemble des résultats de cette thèse ont des retombées importantes sur la gestion des rivières en évaluant, de façon cohérente, l’impact de la régulation des rivières sur les communautés de poissons et en développant des outils de prévision pour la restauration des écosystèmes riverains.
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Artrópodos associados à copa de árvores, principalmente palmeiras, são pouco conhecidos no Cerrado. Para descrever a estrutura da comunidade de artrópodos à copa de Mauritia flexuosa (Arecaceae) foram amostradas 150 palmeiras em seis veredas” do Distrito Federal, de áreas silvestres, rurais e periurbanas na estação chuvosa. Os artrópodos presentes nos ninhos abandonados de aves, refúgios de mamíferos, folhas e matéria orgânica foram coletados manualmente, fixados em etanol 70% e separados em ordem, família, morfoespécie e guildas alimentares. As características das palmeiras medidas foram altura da estipe, diâmetro da copa, número de folhas e de ninhos de aves nas palmeiras. Foram coletados 3.862 indivíduos, pertencentes a 15 ordens, 45 famílias e 135 morfoespécies. As ordens mais abundantes foram Coleoptera (28,6%), Blattodea (21,8%), Collembola (11,4%) e Hemiptera (10,2%). As famílias Blaberidae, Tenebrionidae, Entomobryidae, Reduviidae, Oniscidae, Staphylinidae, Carabidae e Formicidae representaram 82,1% de todos os indivíduos coletados. A maioria das morfoespécies foi pouco abundante, 71 (52,6%) apresentaram uma abundância média igual ou menor que 1 indivíduo/palmeira. Coleoptera compreendeu o maior número de morfoespécies (43,7%) seguida de Araneae (20,0%). A análise das guildas alimentares mostrou prevalência de predadores e hematófagos (36,0%). A riqueza e a abundância de artrópodos foram menores no ambiente periurbano. O número de ninhos de aves apresentou correlação positiva com abundância e riqueza, o que não ocorreu com as medidas das palmeiras. A importância de M. flexuosa para a manutenção da artropodofauna nas “veredas” no bioma Cerrado é discutida. _______________________________________________________________________________________ ABSTRACT
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Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Florestal, Programa de Pós-Graduação em Ciências Florestais, 2016.
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Esta ponencia expone unas reflexiones sobre el prestigio y la dignidad profesional de la bibliotecología en el estado de Nuevo León, México. Analiza y critica: a) la falta de categorías profesionales en Nuevo León en contraste con la UNAM; menciona también como varios bibliotecologos del IMSS Nuevo Leon lucharon porque se tipificara en el contrato colectivo la categoria de Bibliotecologo Profesional y cuya lucha ganaron; b) las actitudes represoras y dictatoriales por parte de las mafias administrativas y academicas de las principales universidades que no permiten la superacion de las amplias mayorias de bibliotecologos y que censuran la libertad de expresion y pensamiento en Nuevo Leon; c) aboga porque los bibliotecologos deban tener mistica de servicio como si se tratara de un "apostolado" en contra del "monetarismo" o "mercenarismo" que en la actualidad mueve a los bibliotecologos nuevoleoneses. En el aspecto gremial critica la charlataneria y oportunimo demagogico de gremios como los de AMBAC de Nuevo Leon, que se aprovechan de las ineptitudes de los gobiernos en todos los niveles en materia bibliotecaria y utilizan las desgracias naturales apelando a sentimentalismos de la gente solo para salir en la foto y en la prensa, pero sin analizar, criticar ni denunciar las fallas estructurales de fondo del Estado mexicano y de los tres niveles de gobierno. ABSTRACT This paper analyses some reflections about the professional prestige and dignity of librarianship in the state of Nuevo Leon, Mexico. It analyses and criticises: a) the lack of professional categories for librarians with B.A.s or Masters degrees in Nuevo Leon, in contrast, for example with Mexico’s National Autonomous University (UNAM); it also assesses how several librarians with B.A. undergraduate degrees from the Mexican National Institute of Social Security (IMSS) the national health service system) in the Nuevo Leon state-wide fought to obtain a Professional B.A. Undergraduate Degre Librarian Labor Cagegory status to be signed and included in the labor IMSS union collective contract and how eventually they won; b) it also criticises the repressive and dictatorial attitudes on the side of the top managerial and academic mafias from the major Nuevo Leon universities who do not allow free and equal academic and professional development opportunities of the vast majorities of librarians with or without B.A. degrees and whom also censor their freedom of expression and thought in Nuevo Leon librarianship; c) it advocates for librarians to have an honest service mystique as if they were doing a sort of "apostleship" against the "monetarist" and "mercenarist" practices that currently practice librarians in Nuevo Leon state. As for the library guild activities, it criticises the demogogical charlatanism and opportunism of guilds such as AMBAC (standing from the Mexico-wide Mexican Library Association, Nuevo Leon chapter), where their leaders only take advantage of the ineptitudes of the three levels of the Mexican government (municipal, state, and federal) on library issues, and they use the natural disasters against libraries or librarians by appealing to people’s sentimentalisms just to appear themselves in the picture and in the press, but without analysing, criticising and denouncing the deep structural faults underneath the Mexican State, and from all the three levels of the Mexican governments.
Viver no campo ou na cidade? resposta dos morcegos (Mammalia, Chiroptera) à antropização da paisagem
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Ecologia, Programa de Pós-Graduação em Ecologia, 2015.