Community descriptors based on attributes have been widely used to make inferences about mounting rules in a community. The level of discrimination used to identify attributes (resolution) influence the estimates of diversity at the community level. Thus, the practical decisions about how the attributes are measured may have repercussions on the patterns of diversity and its correlation with forecast variables. We have developed a framework to evaluate: i) how much information is lost when the resolution on the measurement of performance is reduced, and; II) to what extent the morphological characteristics and phylogeny can be used as a substitute for strategy. We tested also the resolution on the measurement of attributes affects the ability to discriminate different functional diversity marine habitats. We used empirical data from the community of marine fish and correlate with the array of more detailed resolution diet (proportion of food items in the stomach contents of the collected specimens) with matrices (for par) on different resolutions of diet (trophic array based on secondary data; in primary data; primary data of presence and absence of diet food items; primary data as the 0 , 1 and 2 according to itensde foods of importance), eco-morphology and phylogeny. We will then use a functional diversity index (FD) between three regions (influenced by the reef, lagoon and estuary) using different resolutions of attributes, phylogeny and ecomorphology. Phylogeny and ecomorfológicas characteristics were not correlated with the food strategy of the species. However, there was a strong correlation (0.7) between maximum resolution and diet data obtained at the expense of lower resolutions data. Significantly, the resolution was the only one able to discriminate different tropical habitats. These results do not support the use of substitutes for trophic characteristics and highlights the importance the resolution of trophic attributes as a measure to be considered in studies of functional diversity. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Descritores da comunidade baseada em atributos têm sido amplamente utilizados para fazer inferências sobre regras de montagem em uma comunidade. O nível de discriminação usado para identificar atributos (resolução) influencia as estimativas de diversidade ao nível da comunidade. Assim, as decisões práticas sobre como os atributos serão medidos pode ter consequências sobre os padrões de diversidade e sua correlação com variáveis de previsão. Nós desenvolvemos um framework para avaliar: i) quanta informação é perdida quando a resolução na medição de características funcionais é reduzida, e; ii) até que ponto as características morfológicas e filogenia podem ser usados como substitutos de estratégia de alimentação. Nós testamos também se a resolução na medição de atributos afeta a capacidade da diversidade funcional em discriminar diferentes habitats marinhos. Foram utilizados dados empíricos da comunidade de peixes marinhos e correlacionamos com a matriz da resolução mais detalhada de dieta (proporção de itens alimentares no conteúdo estomacal dos exemplares coletados) com as matrizes (par a par) em diferentes resoluções da dieta (matriz trófica com base em dados secundários; em dados primários; dados primários de dieta com presença e ausência de itens alimentares; dados primários como a 0, 1 e 2 de acordo com itensde alimentos de importância), ecomorfologia e filogenia. Nós, então, utilizamos um índice de diversidade funcional (FD) entre três regiões marinhas (influenciado pelo recife, lagoa e estuário) usando diferentes resoluções de atributos, filogenia e ecomorfologia. Filogenia e características ecomorfológicas não foram correlacionadas com a estratégia alimentar das espécies. No entanto, houve uma forte correlação (0,7) entre resolução máxima e dieta obtida por dados, em detrimento a dados de resoluções mais baixas. Significativamente, a resolução foi a única capaz de discriminar diferentes habitats tropicais. Esses resultados não suportam o uso de substitutos para características tróficas e destaca a importância da resolução de atributos tróficos como medida a ser considerada em estudos de diversidade funcional.

Made available in DSpace on 2014-06-11T19:35:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-16Bitstream added on 2014-06-13T19:05:55Z : No. of bitstreams: 1 magnoni_apv_dr_botib.pdf: 4022379 bytes, checksum: 443c6ffc4d48e73996f7b0cb4982f851 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este estudo foi conduzido no reservatório de Chavantes, médio rio Paranapanema, SP/PR, Brasil, sendo o seu objetivo avaliar o papel da compartimentalização deste grande reservatório na distribuição das espécies, partilha de recursos e estrutura e organização trófica das assembléias de peixes. Os peixes foram coletados trimestralmente entre outubro/2005 e julho/2006, com redes de espera, redes de arrasto e peneirão em seis trechos ao longo do gradiente longitudinal do reservatório, representado por dois trechos lóticos (ITA e VER), dois trechos intermediários ou de transição (PAR e FAR) e dois trechos lênticos (BAR e RCL). Foram coletadas 57 espécies no reservatório, sendo que no capítulo 1 apresentam-se a distribuição, abundância e biomassa das espécies nos diferentes trechos, as análises de diversidade (H’), Equitabilidade (E) e β diversidade, e ainda do agrupamento dos trechos de acordo com a abundância das espécies. No capítulo 2 estão apresentadas a composição da dieta, organização trófica, amplitude e sobreposição de nicho trófico de 44 espécies das assembléias de peixes. No capítulo 3 foi analisada a estrutura trófica das assembléias, utilizando-se as variações na abundância e biomassa de 36 espécies pertencentes a 9 guildas tróficas. Os resultados indicam que: 1) as assembléias de peixes apresentam diferenças quanto a composição, abundância e diversidade ao longo do gradiente longitudinal 2) a dieta é um fator importante na segregação das espécies entre os trechos, influenciado pelo elevado consumo de detrito, insetos aquáticos e fragmentos vegetais nos trechos lóticos e intermediários e peixe nos trechos lênticos; 3) as maioria das espécies apresentam alta especialização trófica devido aos baixos valores de amplitude de nicho; 4) a baixa sobreposição de nicho trófico entre os pares de espécies indica... / This study was carried out in the Chavantes Reservoir Middle Paranapanema River, SP/PR, Brazil, to evaluate the role of the longitudinal compartmentalization of this large reservoir in the species distribution, resource partitioning and trophic structure of fish assemblages. Fish were collected every three months from October/2005 to July/2006, with gill nets in six sites along the longitudinal gradient of the reservoir, represented by two lotic (ITA and VER), two transitional (PAR e FAR) and two lentic ones (BAR e RCL). We registered 57 fish species in the reservoir. The chapter 1 presents the distribution, abundance and biomass of fish species, with analysis of species diversity (H’), evenness (E), β diversity, and cluster of the six sites based on the abundance of fish species. The chapter 2 presents the diet composition, trophic organization, niche breadth and niche overlap of 44 species from the fish assemblages. In the chapter 3 was evaluated the trophic structure of assemblages, based in the variation of abundance and biomass of 36 species belonging to 9 trophic guilds. The results indicate that 1) fish assemblages differ in species composition, abundance and diversity along the longitudinal gradient; 2) the diet of fish species is important in their segregation along the sites, affected by the high consumption of detritus, aquatic insects and vegetal matter in the lotic and transitional sites and by fish in the lentic ones; 3) great number of species present high trophic specialization, due to the low values of niche breadth; 4) the low niche overlap observed between pairs indicate that species partition food resources, with no evidence of competition; 5) the high abundance of detritivorous and insectivorous sustain great biomass of piscivorous in many sites. All the results reinforce that longitudinal compartmentalization and environmental aspects of each site are important... (Complete abstract click electronic access below)

Resumo: Este estudo foi conduzido no reservatório de Chavantes, médio rio Paranapanema, SP/PR, Brasil, sendo o seu objetivo avaliar o papel da compartimentalização deste grande reservatório na distribuição das espécies, partilha de recursos e estrutura e organização trófica das assembléias de peixes. Os peixes foram coletados trimestralmente entre outubro/2005 e julho/2006, com redes de espera, redes de arrasto e peneirão em seis trechos ao longo do gradiente longitudinal do reservatório, representado por dois trechos lóticos (ITA e VER), dois trechos intermediários ou de transição (PAR e FAR) e dois trechos lênticos (BAR e RCL). Foram coletadas 57 espécies no reservatório, sendo que no capítulo 1 apresentam-se a distribuição, abundância e biomassa das espécies nos diferentes trechos, as análises de diversidade (H'), Equitabilidade (E) e β diversidade, e ainda do agrupamento dos trechos de acordo com a abundância das espécies. No capítulo 2 estão apresentadas a composição da dieta, organização trófica, amplitude e sobreposição de nicho trófico de 44 espécies das assembléias de peixes. No capítulo 3 foi analisada a estrutura trófica das assembléias, utilizando-se as variações na abundância e biomassa de 36 espécies pertencentes a 9 guildas tróficas. Os resultados indicam que: 1) as assembléias de peixes apresentam diferenças quanto a composição, abundância e diversidade ao longo do gradiente longitudinal 2) a dieta é um fator importante na segregação das espécies entre os trechos, influenciado pelo elevado consumo de detrito, insetos aquáticos e fragmentos vegetais nos trechos lóticos e intermediários e peixe nos trechos lênticos; 3) as maioria das espécies apresentam alta especialização trófica devido aos baixos valores de amplitude de nicho; 4) a baixa sobreposição de nicho trófico entre os pares de espécies indica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract:This study was carried out in the Chavantes Reservoir Middle Paranapanema River, SP/PR, Brazil, to evaluate the role of the longitudinal compartmentalization of this large reservoir in the species distribution, resource partitioning and trophic structure of fish assemblages. Fish were collected every three months from October/2005 to July/2006, with gill nets in six sites along the longitudinal gradient of the reservoir, represented by two lotic (ITA and VER), two transitional (PAR e FAR) and two lentic ones (BAR e RCL). We registered 57 fish species in the reservoir. The chapter 1 presents the distribution, abundance and biomass of fish species, with analysis of species diversity (H'), evenness (E), β diversity, and cluster of the six sites based on the abundance of fish species. The chapter 2 presents the diet composition, trophic organization, niche breadth and niche overlap of 44 species from the fish assemblages. In the chapter 3 was evaluated the trophic structure of assemblages, based in the variation of abundance and biomass of 36 species belonging to 9 trophic guilds. The results indicate that 1) fish assemblages differ in species composition, abundance and diversity along the longitudinal gradient; 2) the diet of fish species is important in their segregation along the sites, affected by the high consumption of detritus, aquatic insects and vegetal matter in the lotic and transitional sites and by fish in the lentic ones; 3) great number of species present high trophic specialization, due to the low values of niche breadth; 4) the low niche overlap observed between pairs indicate that species partition food resources, with no evidence of competition; 5) the high abundance of detritivorous and insectivorous sustain great biomass of piscivorous in many sites. All the results reinforce that longitudinal compartmentalization and environmental aspects of each site are important... (Complete abstract click electronic access below) / Orientador: Edmir Daniel Carvalho / Coorientador: Mário Luis Orsi / Banca: Rosemara Fugi / Banca: Virgínia Uieda / Banca: José Marcelo Rocha Aranha / Banca: Katharina Eichbaum Esteves / Doutor

Submitted by (ana.araujo@ufrpe.br) on 2016-08-22T11:40:08Z No. of bitstreams: 1 Carolina Alves Collier.pdf: 1967577 bytes, checksum: 200ee0c9c05fb39ab23840a268dff357 (MD5) / Made available in DSpace on 2016-08-22T11:40:09Z (GMT). No. of bitstreams: 1 Carolina Alves Collier.pdf: 1967577 bytes, checksum: 200ee0c9c05fb39ab23840a268dff357 (MD5) Previous issue date: 2012-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The dynamics of resource partitioning among species from the same trophic guild, reduces competition and allows coexistence between them. Such sharing can result from different environmental performance and morphological changes resulting from the differential use of food resources. In this study, we evaluated the dynamic of partitioning of food resources in a guild of piscivorous fish, considering the ecomorphology and feeding of the species. Samples were collected monthly, between March/2007 and February/2008, the pond Curralinho, inserted in the semiaridnortheast. We evaluated the five most abundant species ofpiscivorous guild, and they are Acestrorhynchus lacustris, Acestrorhynchus britskii, Hoplias malabaricus, Pygocentrus piraya e Serrasalmus brandtii. The association of the informations trophics and ecomorphologicals of the evaluated piscivores resulted in similar patterns of clustering, demonstrating that the species that used different food resources, also possessed distinct morphological. The first group focused concentrated the two Serrasalminae species, while the second contained Hoplias malabaricus and two species of Acestrorhynchus. Among the species of Serrasalminae and Acestrorhynchus, morphological changes were not observed. However, among the members of Serrasalminae differences were observed in the strategies and food preferences, indicating a partitioning of resources between them. Such sharing can be evidenced by the intermediate value of dietary overlap between these two species. The food overlap index shows high values just within the group formed by H malabaricus and the two Acestrorhynchus species, however H. malabaricus differed in their strategy and food preference, which can contribute to reducing the potentialcompetitive with Acestrorhynchus. Just between the two species Acestrorhynchus did not show differences in strategy and food preference, indicating that theyhad the highest competitive potential between piscivorous evaluated. We emphasize the importance of the concomitant use of analysis ecomorphological and feeding, which is essential to a better understanding of the real trophic sharing. / A dinâmica da partilha de recursos, entre espécies de uma mesma guilda trófica, reduz a competição e possibilita a coexistência entre elas. Essa partilha pode decorrer do desempenho ecológico diferenciado resultante de variações morfológicas e da utilização diferenciada dos recursos alimentares. Neste estudo, avaliou-se a dinâmica da partilha de recursos alimentares numa guilda de peixes piscívoros, considerando a ecomorfologia e alimentação das espécies. As coletas foram realizadas mensalmente, entre março/2007 e fevereiro/2008, na lagoa Curralinho, inserida no semiárido nordestino. Foram avaliadas as cinco espécies mais abundantes da guilda dos piscívoros, sendo elas Acestrorhynchus lacustris, Acestrorhynchus britskii, Hoplias malabaricus, Pygocentrus piraya e Serrasalmus brandtii. A associação das informações ecomorfológicas e tróficas dos piscívoros avaliados resultou em padrões similares de agrupamento, demonstrando que as espécies que utilizaram recursos alimentares diferenciados, também possuíram padrões morfológicos distintos. O primeiro grupo concentrou as duas espécies de Serrasalminae, enquanto o segundo conteve Hoplias malabaricus e as duas espécies de Acestrorhynchus. Entre as espécies de Serrasalminae e Acestrorhynchus não foram observadas variações morfológicas. No entanto, entre os integrantes de Serrasalminae, foram observadas diferenças nas estratégias e preferências alimentares, indicando uma partilha dos recursos entre elas. Essa partilha pode ser evidenciada pelo valor intermediário de sobreposição alimentar entre estas duas espécies. O índice de sobreposição alimentar apresentou altos valores apenas dentro do grupo formado por H. malabaricus e as duas espécies de Acestrorhynchus,, entretanto H. malabaricus diferiu em sua estratégia e preferência alimentar, o que pode contribuir para a redução do potencial competitivo com Acestrorhynchus. Apenas entre as duas espécies de Acestrorhynchus não foram evidenciadas diferenças na estratégia e preferência alimentar, indicando que elas apresentaram o mais elevado potencial competitivo entre os piscívoros avaliados. Ressaltamos a importância da utilização concomitante de análises ecomorfológicas e de alimentação, que são indispensáveis para uma melhor compreensão da real partilha trófica.

The emerald ash borer (EAB, Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a non-native wood boring beetle that is causing extensive ash (Fraxinus spp.) mortality in eastern North America, affecting both urban and wildland forests and drastically altering forest structure and composition. As EAB-induced ash mortality progresses, native arthropod associates of ash forests are impacted by the effects of rapid and broad scale tree mortality. These include loss of food source, increased canopy gap formation, alterations in litter inputs causing shifting temperature and moisture regimes on the forest floor, and significant accumulation of coarse woody debris. I assessed the sub-canopy arthropod community in five forests, all in different stages of the invasion process, from introduction through impact. Additionally, I assessed the ground level arthropod community in a post EAB-invaded forest with 100% mature ash mortality. Arthropod communities were assessed at the ordinal level, and with a focus on coleopterans, they were further classified to families and trophic guilds to analyze abundance, richness, and diversity. Due to their overwhelming abundance, I identified scolytines collected in the post EAB-invaded forest to species to see if the EAB-invasion was part of a greater invasional meltdown. My results indicate that the EAB-invasion in North America is affecting the native coleopteran communities associated with these forests.

Entre les fleuves Amazone et Orénoque, la frange côtière atlantique de l’Amérique du Sud (1500 km) est considérée comme la plus vaseuse au monde, conséquence des apports de sédiments en suspension de l’Amazone. Malgré la forte variabilité et l’instabilité de ces vasières uniques au monde, elles apparaissent comme des écosystèmes très productifs et sont des habitats clés dans l’accomplissement du cycle de vie des espèces de poissons et d’oiseaux qui les exploitent. Cependant, les connaissances sur les communautés biologiques qui y sont associées restent au niveau exploratoire. Ce travail de thèse vise donc à décrire la structure de l’endofaune benthique intertidale des vasières guyanaises et à définir son fonctionnement dans des environnements vaseux tropicaux très instables. Comme prévu, la forte instabilité des sédiments a entraîné une très faible diversité des assemblages de la macrofaune et de la méiofaune. Néanmoins, les communautés benthiques des vasières guyanaises ont montré une abondance remarquablement élevée avec la dominance d'espèces opportunistes de petites tailles. 39 taxons de la macrofaune ont été trouvés tandis que la méiofaune était moins diversifiée avec la présence de 34 taxons. Le tanaidacée Halmyrapseudes spaansi et le polychète Sigambra grubii sont les deux espèces de macrofaune les plus abondantes, largement réparties le long de la côte guyanaise. De même, le nématode Pseudochromadora spp., suceur d’épistrate, et Halomonhystera sp. 1 (non deposit feeders) étaient les deux espèces de méiofaune les plus abondantes sur chacune des stations. La distribution des communautés benthiques sont spécifiques aux sites d’étude et varie saisonnièrement. Les assemblages en zone estuarienne (Sinnamary) étaient plus diversifiées que dans la zone de vasière nue (Awala), alors que les abondances des communautés benthiques étaient toujours plus élevées en saison humide qu’en saison sèche. Les facteurs abiotiques et biotiques ont influencé significativement les communautés benthiques. Néanmoins, les changements dans la structure de la communauté benthique induits par la disponibilité des sources alimentaires (chl a) et la pression de prédation étaient tout aussi importantes que les variations des assemblages imposées par les paramètres abiotiques (teneur en eau, salinité ...). En particulier, une forte corrélation a été trouvée entre la méiofaune et le microphytobenthos. Les mesures isotopiques de différents compartiments des vasières ont non seulement révélé le rôle central du microphytobenthos dans la composition du régime alimentaire de la méiofaune, mais ont également montré l'importance écologique de la méiofaune comme principale source de nourriture pour les petits oiseaux limicoles et les poissons côtiers. La méiofaune et le microphytobenthos rentrent dans le régime alimentaire de trois poissons côtiers en grande proportion, alors que les oiseaux limicoles migrateurs présentaient une plus grande diversité de proies. Cependant, la contribution relative des tanaidacées dans le régime alimentaire des oiseaux limicoles était étonnamment faible. Le travail de thèse a permis d'améliorer notre compréhension de la structure de l’endofaune benthique intertidale des vasières guyanaises et de définir son fonctionnement dans des environnements vaseux tropicaux très instables. Ce travail a permis de construire, pour la première fois, un modèle conceptuel de réseau trophique des vasières intertidales mobiles guyanaises. / Locating between the Amazon and Orinoco Rivers, the 1500 km-long Atlantic coastline of South America are considered as the muddiest areas in the world due to the large discharge of suspended sediment from the Amazon. Despite the extreme morphodynamics of these ecosystems, the Guianas mudflats are important feeding zones for many shorebirds and fish. However, the state of knowledge on benthic organisms associated with these highly unstable environments is still at an exploratory stage. This study, therefore, aims to describe the structure and dynamics of the intertidal benthic infauna in the Guianas mudflats and to define its functioning in such highly unstable tropical muddy environments. As expected, the high instability of the sediment resulted in very low diversity of both macrofauna and meiofauna assemblages. Nonetheless, the infauna communities of the Guianas mudflats showed remarkably high abundance with the predominance of small-sized opportunistic species. A total of 39 operational taxonomic units of macrofauna was recorded while meiofauna was less diverse with the occurrence of 34 taxa. The tanaid Halmyrapseudes spaansi and the polychaeta Sigambra grubii are the two most abundant macrofauna species, which widely distributed along the Guianas coast. Likewise, the nematodes epistrate feeder Pseudochromadora spp. and non-deposit feeders Halomonhystera sp. 1 were the principal components of meiofauna communities in every station. The distribution patterns of the infauna were both site-specific and seasonal variation. The assemblages in estuarine habitat were more diverse than in the bare mudflat habitat, while infauna abundances in the WS were always higher than in the DS. Both abiotic and biotic factors significantly influenced the benthic communities. Nevertheless, the changes in benthic community structure induced by food source availability (chl a) and predation pressure were more prominent than the assemblage variations imposed by abiotic parameters (mud content, salinity…). Particularly, the tight coupling between meiofauna and MPB was observed in both distribution patterns and trophic structures. The isotopic measurements of different intertidal compartments not only revealed the pivotal role of MPB on structuring meiofaunal coummunities, but also indicated the ecological importance of meiofauna as the main food source for the small shorebirds and coastal fish. Meiofauna and MPB entered the diet of three coastal fish in great proportion, whereas the migrating shorebirds showed a wider diet breadth. The isotopic ratios were perfectly matched with the feeding guilds assigned by morphological features. However, the relative contribution of tanaids to the top epibenthic predators were surprisingly lower than expected. The thesis has increased our understanding of the Guianas infauna communities, and revealed for the first time a conceptual food web model of these unique intertidal mudflats.

Au cours de ce travail, nous nous sommes intéressés à l’influence des conditions locales et paysagères sur la structuration des communautés d’arthropodes en agroécosystèmes, ceci grâce à un dispositif de suivi situé en Ille-et-Vilaine (Bretagne, France), et comprenant des parcelles conduites en agriculture biologique et conventionnelle spatialement appariées. Notre première étude a mis en évidence que l’hétérogénéité paysagère, parfois en interaction avec le système local de culture, conditionne la diversité et l’abondance des groupes trophiques, à la fois pour les arthropodes au sol comme pour ceux de la végétation. Dans un second temps, nous avons pu montrer l’importance du contexte paysager dans la structuration des assemblages d’arthropodes prédateurs, et émis l’hypothèse que les mécanismes déterminant la distribution des espèces diffèrent fortement entre araignées et carabiques. Enfin, il est apparu la nécessité de distinguer les individus résidents (émergeants) des individus mobiles (circulants) lorsque l’on s’intéresse au rôle différentiel des facteurs locaux vs. paysagers dans la structuration des communautés de carabiques. D’une façon générale, nos résultats montrent donc une influence importante et positive de l’agriculture biologique sur les populations, assemblages d’espèces et communautés d’arthropodes, que ce soit à des échelles locales et paysagères comme en interaction avec d’autres variables paysagères. Nous avons également montré la pertinence de l’utilisation de différents niveaux d’organisation et variables réponses associées pour évaluer finement la structure et le fonctionnement de communautés d’Arthropodes en agroécosystèmes. / In this study, we got interested in quantifying how local and landscape metrics structure arthropod communities in agro-ecosystems. For that, we used a long-term monitoring design located in ‘Ille-Et-Vilaine’ (Brittany, France), composed by spatially pair-matched fields under organic vs. conventional farming systems. First, we found that landscape heterogeneity, also interacting with farming systems, drives the diversity and abundance of trophic groups for both ground- and vegetation-dwelling arthropods. In a second chapter, we showed the importance of landscape context in shaping assemblages of predatory arthropods, and suggested that mechanisms behind the distribution of individual species strongly differ between spiders and carabids. Lastly, we highlighted the importance of distinguishing between resident (emergent) and mobile (circulating) individuals when assessing the differential role of local vs. landscape factors in community assembly. Overall, our results show a strong and positive effect of organic farming on arthropod populations, assemblages and communities, both at local and landscape scales, as well as in interaction with other landscape metrics. We also highlighted the relevance of using different levels of biological organization, and related response variables, when assessing the structure and functioning of arthropod communities in agroecosystems