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Diversidade taxonômica, filogenética e funcional de aves em gradientes ambientais na caatingaCorreia, Kelly Isadora de Oliveira 27 July 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Biological diversity is a broad, deep and multifaceted concept that describes all variability of
living forms on different spatial and temporal scales and levels of organization. Even among
species, diversity can assume distinct characters, including a taxonomic, a phylogenetic and
a functional one. Semiarid ecosystems such as the Caatinga were poorly addressed from an
integrated perspective of its biodiversity. The region possess high biotic variability and
undergoes intense pressures from abiotic and anthropogenic factors. With around 500 species
known in the biome, birds compose an expressive biological group in the Caatinga, with
distinct evolutionary lineages and ecological features. This study aims to understand the
evolutionary and ecological aspects of the diversity of birds of the Caatinga and their
environmental drivers. Specifically, we aim to (i) summarize the existing knowledge on birds
assemblages in the biome, their phylogenetic relationships and ecological (i.e., functional)
differences; (ii) investigate the interrelationships among taxonomic, phylogenetic and
functional diversity, including their distinct measures; (iii) evaluate the effects of different
environmental (climatic and structural) gradients on these different dimensions of bird
diversity; and (iv) evaluate the effects of these factors on the functional diversity based on
individual traits. We gathered information of 123 birds assemblages from the Caatinga based
on the available literature, and used a species-level phylogenetic tree and a set of speciesspecific
functional traits to estimate the phylogenetic and functional diversities, respectively.
Also, we explored different diversity metrics, aiming to understand their interrelationships
and select those less biased by species richness and sampling effort. 523 species composed
the regional diversity of the Caatinga. The phylogenetic and functional diversity patterns
were coincident regarding spatial distribution and environmental hypothesis, with current
climate as the leading factor. Nonetheless, the diversity of individual traits diverged
qualitatively and quantitatively from the total functional diversity. These results reinforce the
need to intensify the sampling efforts in the Caatinga, allow us to comprehend the effects of
environmental conditions on birds assembling in ecological and evolutionary terms and,
finally, warns to the problem of selecting ecological traits to describe functional diversity. / Diversidade biológica é um conceito amplo, profundo e multifacetado que descreve toda
variabilidade de formas de vida em diferentes escalas espaciais, temporais e níveis de
organização. Mesmo entre espécies, a diversidade pode assumir distintos caráteres, incluindo
o taxonômico, o evolutivo e funcional. Ecossistemas semiáridos como a Caatinga foram
pouco estudados sob uma perspectiva integrada da biodiversidade. A região possui alta
variabilidade biótica e sofre intensa pressão de fatores abióticos e antrópicos. Com cerca de
500 espécies conhecidas no bioma, as aves compõem um grupo biológico expressivo da
Caatinga, com distintas linhagens evolutivas e características ecológicas. Este trabalho
objetiva compreender os aspectos evolutivos e ecológicos da diversidade de aves da Caatinga
e seus determinantes ambientais. Especificamente, buscamos (i) sumarizar o conhecimento
existente sobre as assembleias de aves do bioma, suas relações filogenéticas e diferenças
ecológicas (funcionais); (ii) investigar as inter-relações entre a diversidade taxonômica,
filogenética e funcional, incluindo distintas medidas destas; (iii) avaliar os efeitos de
diferentes gradientes ambientais (climáticos e estruturais) sobre essas diferentes dimensões
da diversidade; e (iv) avaliar os efeitos desses fatores sobre a diversidade funcional de traços
individuais. Reunimos informações de 123 assembleias de aves da Caatinga a partir da
literatura disponível e utilizamos uma árvore filogenética das espécies e um conjunto de
traços funcionais espécie-específicos para estimar a diversidade filogenética e funcional,
respectivamente. Ainda, exploramos diferentes métricas de diversidade, a fim de entender
suas inter-relações e selecionar aquelas menos enviesadas pela riqueza e esforço amostral.
523 espécies compuseram a diversidade regional da Caatinga. Os padrões de diversidade
filogenética e funcional foram coincidentes quanto à distribuição espacial e a hipótese
ambiental, tendo o clima atual como fator principal. Entretanto, a diversidade de traços
funcionais individuais divergiu qualitativa e quantitativamente da diversidade funcional total.
Esses resultados reforçam a necessidade de intensificar os esforços amostrais na Caatinga,
permitem compreender o efeito das condições ambientais na formação das assembleias de
aves em termos ecológicos e evolutivos, e por fim, alerta para o problema de selecionar traços
ecológicos para descrever a diversidade funcional.
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Diversité et structure du zooplancton : importance pour la conservation de la biodiversité aquatique en zone urbaineMimouni, El-Amine 06 1900 (has links)
L'écologie urbaine est un nouveau champ de recherche qui cherche à comprendre les structures et les patrons des communautés et des écosystèmes situés dans des paysages urbains. Les petits plans d’eau sont connus comme des écosystèmes aquatiques qui peuvent contenir une biodiversité considérable pour plusieurs groupes taxonomiques (oiseaux, amphibiens, macroinvertébrés), ce qui en fait des écosystèmes intéressants pour les études de conservation.
Cependant, la biodiversité du zooplancton, un élément central des réseaux trophiques aquatiques, n’est pas entièrement connue pour les plans d’eaux urbains et devrait être mieux décrite et comprise. Cette étude a évalué les patrons de biodiversité des communautés zooplanctoniques dans des plans d’eau urbains sur l’Ile de Montréal et leurs sources de variation. Des suggestions pour l’évaluation et la conservation de la biodiversité sont aussi discutées.
La biodiversité zooplanctonique des plans d’eaux urbains s’est avérée être assez élevée, avec les cladocères et les rotifères montrant les contributions à la diversité gamma et bêta les plus élevées. Sur l’ensemble des plans d’eau, il y avait une corrélation négative entre les contributions à la bêta diversité des cladocères et des rotifères. Au niveau de chaque plan d'eau, la zone littorale colonisée par des macrophytes s'est avérée être un habitat important pour la biodiversité zooplactonique, contribuant considérablement à la richesse en taxons, souvent avec une différente composition en espèces. Les communautés zooplanctoniques répondaient aux facteurs ascendants et descendants, mais aussi aux pratiques d’entretien, car le fait de vider les plans d’eau en hiver affecte la composition des communautés zooplanctoniques.
Les communautés de cladocères dans ces plans d’eau possédaient des quantités variables de diversité phylogénétique, ce qui permet de les classer afin de prioriser les sites à préserver par rapport à la diversité phylogénétique. Le choix des sites à préserver afin de maximiser la diversité phylogénétique devrait être correctement établi, afin d’eviter de faire des choix sous-optimaux. Cependant, pour des taxons tels que les cladocères, pour lesquels les relations phylogénétiques demeurent difficiles à établir, placer une confiance absolue dans un seul arbre est une procédure dangereuse. L’incorporation de l’incertitude phylogénétique a démontré que, lorsqu’elle est prise en compte, plusieurs différences potentielles entre la diversité phylogenétique ne sont plus supportées.
Les patrons de composition des communautés différaient entre les plans d’eau, les mois et les zones d’échantillonnage. Etant donné les intéractions sont significatives entres ces facters; ceci indique que tous ces facteurs devraient êtres considérés. L’urbanisation ne semblait pas sélectionner pour un type unique de composition des groupes alimentaires, étant donné que les communautés pouvaient changer entres des assemblages de types alimentaires différents. Les variables environnementales, surtout la couverture du plan d’eau en macrophytes, étaient des facteurs importants pour la biodiversité zooplanctonique, affectant la richesse spécifique de divers groupes taxonomiques et alimentaires. Ces variables affectaient aussi la composition des communautés, mais dans une moindre mesure, étant des variables explicatives modestes, ce qui indiquerait le besoin de considérer d’autres processus. / Urban ecology is an emerging research field that seeks to understand the structures and patterns of communities and ecosystems located in urban landscapes. Small waterbodies are known as aquatic ecosystems that can harbour notable biodiversity for various taxonomic groups (birds, amphibians, macroinvertebrates), making them interesting ecosystems for conservation studies.
However, the biodiversity of zooplankton, a central element of aquatic trophic networks, is still not entirely known for urban waterbodies and should be better described and understood. This study examined the biodiversity patterns of zooplanktonic communities in urban waterbodies on the Island of Montreal and their sources of variation. Suggestions for biodiversity assessment and for biodiversity preservation are also discussed.
Zooplankton biodiversity urban waterbodies proved to be quite high, with cladoceran and rotifer taxa showing the highest contributions to gamma and beta diversity. Across waterbodies, there was a negative correlation between the contributions to cladoceran and rotifer beta diversity. Within waterbodies, the littoral zone showing macrophytes proved to be an important habitat for zooplankton biodiversity, considerably contributing species richness, often with a different species composition. Zooplankton communities responded to bottom-up and top-down forces, but also management practices, as waterbody emptying in winter affected zooplankton community composition.
Cladoceran communities in these waterbodies showed varying amounts of phylogenetic diversity, which allowed them to be ranked in order to prioritize sites to preserve with regards to phylogenetic diversity. Selection of sites to preserve in order to maximize phylogenetic diversity should be properly guided, in order to avoid making suboptimal choices. However, for taxa such as Cladocera, for which phylogenetic relationships remain difficult to establish, placing absolute confidence in a single tree is a dangerous procedure. Incorporation of phylogenetic uncertainty showed that, when it is taken into account, then several potential differences in phylogenetic diversity were not supported anymore.
Community composition patterns differed between waterbodies, months and sampling zones. Due to the presence of significant interactions between these factors, this indicates that all these factors should be considered. Urbanization did not seem to select for a single type of feeding group composition, as communities in waterbodies could shift between assemblages with different feeding types. Environmental variables, especially waterbody macrophyte coverage, were important factors for zooplankton biodiversity, positively affected species richness of various taxonomic groups and feeding groups. These variables also affected community composition, but to a lesser extent, being modest predictor variables, indicating the need to consider other processes.
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