Maintaining the ecological health of streams is vital for sustainable water resources management. Streamflow is a primary factor influencing the structure and function of ecological communities. A quantitative understanding of how stream biota respond to variation in streamflow is required for stream bioassessment. This dissertation focuses on quantifying relationships between streamflow regime and stream macroinvertebrate richness and composition. The contribution comprises statistical models that predict stream macroinvertebrate class from streamflow regime and predict streamflow regime from watershed attributes, and a tool that helps derive watershed attribute variables used in these models. The dissertation is a collection of three papers. In the first paper 12 variables were used to represent streamflow regime at 543 sites in the western US. Principal component analysis (PCA) and K-means clustering were used to obtain statistically independent factors and streamflow regime classes. We examined the relationship between these characterizations of streamflow and macroinvertebrate richness and composition at 63 of the 543 sites where there was also biological data. This analysis identified specific aspects of the streamflow regime that were useful in predicting macroinvertebrate richness and composition and that have potential application in classification-based bioassessment and management. A regional-scale study such as this requires tools for efficiently delineating watersheds and deriving their attributes. Paper two presents a multiple watershed delineation tool that addresses issues such as a) incorrectly positioned outlets and b) large Digital Elevation Models. This tool has capabilities to delineate stream networks with the threshold that determines drainage density being objectively determined so that the resulting networks adhere to geomorphological stream network laws. It also derives a suite of geomorphological watershed attributes that were used in prediction models in paper three. In paper three, we developed statistical models to predict streamflow regime class from watershed attributes. Four popular statistical methods were used and the uncertainty associated with class predictions for each method was quantified. Paper three also identified the watershed attributes that were most important for discriminating streamflow regime classes.

In the Oueme River, a lowland river in Benin, Africa, artificial ponds constructed in the floodplain (whedos) are colonized during the high-water period by a presumably random sample of fishes from the river channel. As water slowly recedes from the floodplain, fishes are isolated in whedos until they are harvested near the end of the dry season. I surveyed fishes in whedos and adjacent main-channel and floodplain habitats during two low-water (2008 and 2009) and one falling-water (2010-2011) periods, and measured a suite of physicochemical variables including dissolved oxygen, temperature, specific conductivity, and percent cover of aquatic vegetation in the falling-water period to investigate if fish assemblage structure of whedos resulted from stochastic or deterministic processes. I also investigated food web structure of whedos by analyzing carbon (delta13C) and nitrogen (delta15N) stable isotope ratios of fish and primary producer tissue samples, and samples of net primary production, soluble reactive phosphorus (SRP), NH4+, NO2-, and NO3- collected during the falling-water period. Whedos were covered with dense growth of aquatic vegetation, and dissolved oxygen concentrations were lower in whedos compared to a natural floodplain depression and the main channel. Multivariate analyses revealed that habitat types were distinct with regard to fish assemblage structure and abiotic conditions. Assemblages in whedos and natural floodplain depressions were differentiated from those of the river channel, with the floodplain habitats being dominated by piscivorous fishes that tolerate aquatic hypoxia. These results indicate that fish assemblage structure of whedos was influenced by deterministic processes during the falling- and low-water periods when these water bodies were isolated. Floodplain habitats were more nutrient-rich than the river channel, and whedos were net heterotrophic. Microphytobenthos and C3 macrophytes accounted for a large fraction of fish biomass in whedos, compared with the river channel, which was mainly supported by seston. Whedo food webs had fewer trophic transfers compared to the food web of the river channel.

Made available in DSpace on 2014-06-11T19:30:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-19Bitstream added on 2014-06-13T20:00:50Z : No. of bitstreams: 1 araujo_rb_dr_jabo.pdf: 1067716 bytes, checksum: 706c3ec31777349a033e768e87ccffee (MD5) / Na planície de inundação do alto rio Paraná, lagoas marginais são viveiros naturais de espécies comercialmente importantes e habitat preferencial de peixes sedentários e de pequeno porte. No presente estudo, foram investigadas a composição e a abundância de comunidades de peixes em lagoas marginais (temporárias e permanentes) sazonalmente isoladas do rio Turvo, incluindo alterações qualitativas e quantitativas nas estações seca e chuvosa e sua relação com fatores ambientais. O material foi coletado em ambas as estações em seis lagoas marginais. As comunidades de peixes foram analisadas por meio de riqueza de espécies, diversidade e equitabilidade, similaridade qualitativa e quantitativa, e associações ecológicas entre amostras, espécies e variáveis ambientais. Foi registrado um total de 7.456 exemplares, distribuídos em 52 espécies, 40 gêneros, 19 famílias, e cinco ordens. As espécies mais abundantes foram Astyanax altiparanae, Serrapinnus heterodon, Liposarcus anisitsi, Hyphessobrycon eques, and Moenkahausia intermedia. A análise de agrupamento mostrou baixa similaridade entre as lagoas, sugerindo heterogeneidade desses ambientes. A composição e abundância das comunidades de peixes nas lagoas estudadas mostraram acentuada sazonalidade, sendo maiores os valores de riqueza e abundância obtidos na estação chuvosa. A análise de correspondência canônica revelou que temperatura da água, alcalinidade e abundância de anfíbios foram significativamente associadas à estrutura da ictiofauna. / In the Upper Paraná River floodplain, marginal lagoons are natural nurseries of commercially important fish species and preferential habitat of sedentary and small-sized fish species. The composition and abundance of fish communities in seasonally isolated lagoons (temporary and permanent) of the rio Turvo, qualitative and quantitative changes in the dry and rainy seasons, as well as relationship with environmental factors, were investigated. The material was sampled in both seasons in six marginal lagoons. The ichthyofauna was studied through species richness, diversity, evenness, qualitative and quantitative similarities, and ecological associations between the samples and species along an environmental gradient. A total of 7,457 specimens, distributed among 52 species, 40 genera, 19 families, and five orders, were recorded. The most abundant species were Astyanax altiparanae, Serrapinnus heterodon, Liposarcus anisitsi, Hyphessobrycon eques, and Moenkahausia intermedia. Cluster analysis showed a low similarity among lagoons suggesting heterogeneity of these environments. The composition and abundance of fish communities in the studied marginal lagoons showed a remarkable seasonality, with highest values of species richness and abundance obtained in the rainy season. Canonical correspondence analysis revealed that the water temperature, alkalinity, and amphibian abundance were significantly associated with the ichthyofauna structure.

Submitted by João Henrique Costa (henrique@biblioteca.ufpb.br) on 2016-12-22T15:17:04Z No. of bitstreams: 1 Arquivototal.pdf: 2614769 bytes, checksum: d7bbe30a1e75e204fc7eb00f5f993d53 (MD5) / Made available in DSpace on 2016-12-22T15:17:04Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 2614769 bytes, checksum: d7bbe30a1e75e204fc7eb00f5f993d53 (MD5) Previous issue date: 2014-10-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The structure of assemblages may be the result of recent events (e.g., ecological interactions or resources availability), as well as historical factors (like evolutionary events). The segregation of resources may be analyzed by morphometric, dietary, microhabitats, and even acoustical data. This thesis aims to test hypotheses related to the structure of an anuran assemblage and related niche segregation by using: (1) morphometric and ecological (dietary and microhabitat) data and (2) bioacoustical data. For the first approach, we collected data from 598 individuals, from 30 species. The results showed that the assemblage is not structured in terms of microhabitat usage. However, competition among phylogenetic related species is pronounced. Besides, the assemblage presents structure regarding dietary data. This result supports the existence of avoidance by competition within the studied assemblage. The effect of phylogenetic niche conservatism is also observed for the usage of microhabitat, and for morphometric and dietary variables. Based on that, we state that the species may coexist because they segregate their niche, at least in one dimension, and that the use of some specific niche component are related to their evolutionary history. For the second approach – using acoustical variables collected from advertisement calls – it was collected data from 15 species. The result has demonstrated that the majority of species present acoustic differences in their calls. The results support our hypothesis of acoustic niche partitioning (at least moderately), corroborating other studies which assert that the acoustical niche occupancy is species-specific. / A maneira como as taxocenoses se estruturam pode ser considerada reflexo de eventos recentes (p.e., interações ecológicas ou disponibilidade de recursos), bem como dos fatores históricos (como eventos evolutivos). Essa partilha de recursos pode ser estudada por meio de morfometria, dieta, microhábitats ou mesmo dados acústicos das espécies. A presente dissertação aborda a temática de estrutura de taxocenose e a partição de nicho para anfíbios anuros por meio de: (1) caracteres morfométricos e ecológicos (dieta e microhábitat) e (2) caracteres bioacústicos. Para a primeira, foram coletados dados de 598 indivíduos, distribuídos entre 30 espécies. Os resultados das análises mostram que a taxocenose não se encontra estruturada em relação aos dados de microhábitat, porém existe uma maior competição entre espécies filogeneticamente próximas. Já para os dados de dieta, a taxocenose encontra-se estruturada, mostrando que as espécies evitam a competição. Além disso foi possível observar conservantismo filogenético para morfometria, para o nicho alimentar e o nicho de microhábitat. Esses dados mostram que as espécies coexistem pois particionam o nicho em, ao menos, alguma dimensão e que, ao menos em parte, a ocupação de determinados nichos está relacionada com a história evolutiva das espécies de anuros encontradas. Para a segunda abordagem, relacionada aos caracteres acústicos dos cantos de anúncio dos anuros, foram coletados dados individuais de 16 espécies. Os resultados das análises realizadas demonstram que a maioria das espécies apresentaram diferenças entre si, apresentando características minimamente distintas a fim de evitar a sobreposição. Esses resultados corroboram, para a maior parte das espécies, nossa hipótese que o nicho acústico encontra-se particionado, apoiando outros trabalhos que afirmam que o sinal acústico é espécie-específico e, portanto, apresentará características diferentes entre as espécies.

Orientador: Francisco Langeani Neto / Banca: Oscar Akio Shibatta / Banca: Lilian Casatti / Banca: Antonio Fernando Monteiro Camargo / Banca: Luiz Henrique Florindo / Resumo: Na planície de inundação do alto rio Paraná, lagoas marginais são viveiros naturais de espécies comercialmente importantes e habitat preferencial de peixes sedentários e de pequeno porte. No presente estudo, foram investigadas a composição e a abundância de comunidades de peixes em lagoas marginais (temporárias e permanentes) sazonalmente isoladas do rio Turvo, incluindo alterações qualitativas e quantitativas nas estações seca e chuvosa e sua relação com fatores ambientais. O material foi coletado em ambas as estações em seis lagoas marginais. As comunidades de peixes foram analisadas por meio de riqueza de espécies, diversidade e equitabilidade, similaridade qualitativa e quantitativa, e associações ecológicas entre amostras, espécies e variáveis ambientais. Foi registrado um total de 7.456 exemplares, distribuídos em 52 espécies, 40 gêneros, 19 famílias, e cinco ordens. As espécies mais abundantes foram Astyanax altiparanae, Serrapinnus heterodon, Liposarcus anisitsi, Hyphessobrycon eques, and Moenkahausia intermedia. A análise de agrupamento mostrou baixa similaridade entre as lagoas, sugerindo heterogeneidade desses ambientes. A composição e abundância das comunidades de peixes nas lagoas estudadas mostraram acentuada sazonalidade, sendo maiores os valores de riqueza e abundância obtidos na estação chuvosa. A análise de correspondência canônica revelou que temperatura da água, alcalinidade e abundância de anfíbios foram significativamente associadas à estrutura da ictiofauna. / Abstract: In the Upper Paraná River floodplain, marginal lagoons are natural nurseries of commercially important fish species and preferential habitat of sedentary and small-sized fish species. The composition and abundance of fish communities in seasonally isolated lagoons (temporary and permanent) of the rio Turvo, qualitative and quantitative changes in the dry and rainy seasons, as well as relationship with environmental factors, were investigated. The material was sampled in both seasons in six marginal lagoons. The ichthyofauna was studied through species richness, diversity, evenness, qualitative and quantitative similarities, and ecological associations between the samples and species along an environmental gradient. A total of 7,457 specimens, distributed among 52 species, 40 genera, 19 families, and five orders, were recorded. The most abundant species were Astyanax altiparanae, Serrapinnus heterodon, Liposarcus anisitsi, Hyphessobrycon eques, and Moenkahausia intermedia. Cluster analysis showed a low similarity among lagoons suggesting heterogeneity of these environments. The composition and abundance of fish communities in the studied marginal lagoons showed a remarkable seasonality, with highest values of species richness and abundance obtained in the rainy season. Canonical correspondence analysis revealed that the water temperature, alkalinity, and amphibian abundance were significantly associated with the ichthyofauna structure. / Doutor

Abstract In this thesis, I studied spatial and temporal variability of macroinvertebrate assemblages of boreal streams. The main objectives were (i) to characterize macroinvertebrate assemblage types across large geographical extents, and to assess the utility of assemblage types and landscape and stream type classifications as the basis of stream bioassessment and conservation programs (ii, iii). I also examined the relative roles of large-scale spatial trends and local environmental conditions in structuring macroinvertebrate assemblages (iv). Finally, I assessed (v) if assemblage classifications produce temporally stable and predictable assemblage types. Stream macroinvertebrate assemblage structure exhibited continuous variation instead of distinct assemblage types. Although ecoregions clearly accounted for a considerable amount of variation of macroinvertebrate assemblage characteristics, a combination of regional stratification and prediction from environmental factors would probably yield the most comprehensive framework for the characterizations of macroinvertebrate assemblages of boreal headwater streams. Differences in macroinvertebrate assemblage structure, as well as a group of effective indicator species for different stream types, suggest that landscape classifications could be used as a preliminary scheme for the conservation planning of running waters The strength of the relationship between assemblage structure and local environmental variables increased with decreasing extent, whereas assemblage variation related to spatially variables showed the opposite pattern. At the largest scale, spatial variation was related to latitudinal gradients, while spatial autocorrelation among neighbouring streams was the likely mechanism creating spatial structure within drainage systems. These results suggest that stream bioassessment should give due attention to spatial structuring of stream assemblage composition, considering that important assemblage gradients may not only be related to local environmental factors, but also to biogeographical constraints and neighbourhood dispersal processes. The classification strengths of macroinvertebrate assemblages based on data of three years were overall rather weak, and more importantly, the compositions of the site groups varied considerably from year to year. Such wide and continuous variation was also mirrored by low and inconsistent predictability of classifications from environmental variables. The observed level of temporal variation in assemblage structure may not be a serious problem for predictive approaches frequently used in bioassessment of freshwater ecosystems. For conservation purposes, however, alternative approaches (e.g. physical surrogates of biodiversity) need to be considered.

Changes in land cover and fish assemblage structure were assessed across two spatial and temporal scales in the Piedmont and Coastal Plain regions of the Chesapeake Bay watershed in Virginia. A long-term, local study (1953 to 2014) on the Tuckahoe Creek watershed used digitized aerial photography and satellite images (Landsat 5 TM and Landsat 8 OLI/TIRS) to quantify land cover change for five nested catchments in 1953, 1990, and 2014. Instream fish collections from 1958, 1990, and 2014 were utilized to assess a variety of fish assemblage metrics for each of the five catchments, and analyses were performed to assess associations between changes in land cover and changes in fish assemblage structure across all three time periods. A short-term, regional study assessed 21 catchments in the region using 1997 Landsat 5 TM satellite images and 2014 Landsat 8 OLI/TIRS satellite images to quantify land cover change. Fish collections from 1995-1999 and 2014 were utilized to assess a variety of fish assemblage metrics from samples taken at instream sites for each of the 21 catchments. Analyses were performed to discover any associations between changes in land cover and changes in fish assemblage structure from a regional perspective. This study found that there were significant changes in land cover over all study periods in the Tuckahoe Creek watershed and that land cover changes were correlated to changes in fish assemblage structure over the long-term study. Regionally, there were significant changes in land cover, with no correlation to changes in fish assemblage structure found. The data suggests that anthropogenic alterations to the landscape have had long-term effects on fish assemblage structure in Tuckahoe Creek, but the results from the short-term assessments did not detect a relationship between land cover changes and changes in fish assemblage structure. It is possible that the fish communities were already established in moderately degraded catchments by the 1990s due to previous anthropogenic stressors.

The major human activities that have transformed the Earth include agriculture and urbanization. The present study was conducted to contribute to a description of the effect on birds of urbanization and agriculture in an Indian region. Terrestrial bird assemblages were censused along a five-stage urbanisation gradient between January and April 2010-2013 near the city of Amravati, on the Deccan Plateau, Central India. Altogether, 89 species of birds were recorded, with the highest species richness in the rural areas (67 species) and lowest in the urban stage (29 species). The assemblages were significantly nested in all the five stages. Maximum cumulative species abundance (12 399 individuals over four years) was found in the urban stage, and was due to the constant presence of large groups of Rose-ringed Parakeets (Psittacula krameri). The lowest bird abundance was found in the industrial zone (4837 in total), where there was also a nearly two-fold decrease from 2010 to 2013. Thirty-six species demonstrated significant variation in their densities at least in one stage and between at least two months (p&lt;0.05). Densities of 13.9% (n=5) of those species varied significantly in two stages, that of Copsychus saularis in three stages, and of Phoenicurus ochruros, in all five stages. Urban, suburban, periurban and forest stages were characterised by relatively stable species densities (significant changes observed only for 17.2% (n=5), 17.1% (n=6), 12.9% (n=7), and 17.8% (n=16) species, respectively). The additive diversity partitioning indicated that of the overall diversity (gamma-diversity), alpha diversity (within transects located within one stage) contributed 50.1% to the total diversity, and the controbution of within-stage variability was small (2.7%). Additionally, censuses on cultivated fields were taken. In two areas under mixed cropping systems, 53 bird species were identified in the two years period between June and December, 2011 and 2012. Out of the 53 detected species, only 14 were common (recorded at ≥50% of visits). Twenty-one species were recorded at Zadgaon in crops of tur (Cajanus cajan), cotton (Gossypium arboreum) and soybean (Glycine max). Nineteen species were recorded at Bhankhed in jawar (Sorghum bicolor), cotton and mung bean (Phaseolus aureus). At Zadgaon, territorial activity was observed in four species: the House Sparrow (Passer domesticus), Jungle Babbler (Turdoides striata), Yellow-eyed Babbler (Chrysomma sinense) and Red-wattled Lapwing (Vanellus indicus). The study indicated that four bird species were found under high risk, thirteen species at medium risk and eight species at low risk due to pesticide applications in croplands. The extent of crop damage in fields of groundnut, pearl millet, peas, sorghum, and sunflower was assessed by doing actual field censuses. The sustainable solution for reducing crop damage is a need for the farmers and such techniques will help to avoid direct or indirect effects of use of lethal bird control techniques on bird species diversity. / <p>QC 20141022</p>

Made available in DSpace on 2015-04-17T14:55:19Z (GMT). No. of bitstreams: 1 arquivototal.PDF: 1079008 bytes, checksum: 6627885b56d1a7d7174f7cbfaceacfb7 (MD5) Previous issue date: 2012-02-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In theroy, the influence of phylogeny in community structure implies that phylogenetically close species may show similar characteristics determined by their evolutionary history. In a fine scale, this is useful to identify processes of microevolution. We used phylogenetic and ecological data to investigate the determinant factors of the relationships among 15 anuran species in temporary ponds in Caatinga. Phylogenetically close species used the same categories of microhabitat, but they differed in usage proportion. Considering diet, overlap values were high in phylogenetically related species and these species tended to form concise groups. Analysis based on null models indicated no significant values of overlap in microhabitat usage and diet composition, showing that competition is unlikely to regulate assemblage structure. Species belonging to the same phylogenetic lineage occupied the same morphological space, suggesting that morphometry may be a conservative trait; however, some close related species have diverged in this pattern. The joint observation of microhabitat usage, diet composition, and morphology indicated the existence of similarities among phylogenetically related species. Canonical Phylogenetic Correlation Analysis revealed the presence of niche phylogenetic conservatism in microhabitat usage in Hylidae and Leptodactyliformes basal dichotomy and in diet composition of the Physalaemus genus. In this work, it is considered that the phylogenetic relationships influence assemblage structure. However, the observation of differences in resource usage among closely related species and similarities among unrelated species suggests the existence of ecological factors acting at some moment of the evolution of these organisms. / Teoricamente a influência da filogenia na estrutura de comunidades implica que espécies próximas filogeneticamente podem apresentar características semelhantes determinadas pela sua história evolutiva. Em uma escala fina isto é útil na identificação de processos de micro-evolução. Aqui utilizamos dados ecológicos e filogenéticos para investigar os fatores determinantes das relações entre 15 espécies de anuros em poças temporárias na Caatinga. Espécies próximas filogeneticamente utilizaram as mesmas categorias de microhábitats, mas diferiram na proporção do uso. Considerando a dieta, valores de sobreposição foram altos em espécies relacionadas filogeneticamente e estas tenderam a formar grupos concisos. Uma análise baseada em modelos nulos indicou valores não significativos de sobreposição no uso do microhábitat e na composição da dieta, evidenciando que a competição não parece regular a estrutura da taxocenose. Espécies damesma linhagem filogenética ocuparam o mesmo espaço morfológico sugerindo que a morfometria pode ser um traço conservativo, no entanto, algumas espécies próximas divergiram deste padrão. A observação conjunta do uso do microhábitat, composição da dieta e morfologia indicou a existência de similaridades entre espécies relacionada filogeneticamente. Análise de Correlação Filogenética Canônica revelou presença de conservação filogenética de nicho no uso do microhábitat na dicotomia basal Hylidae eLeptodactyliformes e na composição da dieta do gênero Physalaemus. Aqui consideramos que as relações filogenéticas exercem influência sobre a estrutura da taxocenose, no entanto, a observação de diferenças no uso dos recursos entre espécies próximas e similaridades entre espécies não relacionadas sugere a existência de fatores ecológicos atuando em algum momento da evolução destes organismos.

The Florida Reef Tract (FRT) extends from the tropical Caribbean up the southeast coast of Florida into a temperate environment where tropical reef assemblages diminish with increasing latitude. This study used data from a three-year comprehensive fishery-independent survey to quantify reef fish spatial distribution along the Southeast FRT and define where the assemblage shifts from tropical to temperate. A total of 1,676 reef fish visual census samples were conducted to assess the populations on a stratified-random selection of sites of marine hardbottom habitats between the Miami River and St. Lucie inlet. Multivariate analyses were used to investigate differences in assemblages among sites. Depth (m), general habitat (reef or hardbottom), and slope (high or low) strata were examined to explain the dissimilarities between assemblages. A general trend of cold-tolerant temperate fish dominated the northern assemblages and more tropical species dominated further south. Seven reef fish assemblage biogeographic regions were determined. In shallow habitats the data clustered in three spatial regions: One south of Hillsboro inlet, one in Northern Palm Beach south of Lake Worth inlet, and one north of Lake Worth inlet. The assemblage in deep habitats mainly split in close proximity to the Bahamas Fracture Zone south of Lake Worth Inlet. The presence of reef habitat aided in splitting the southern assemblage regions from the northern all-hardbottom assemblage regions in both the shallow and deep habitats. Substrate relief was significantly correlated with the differences in the northernmost deep assemblages but did not appear to affect the remainder of the shallow and deep assemblages. This bioregional study creates a baseline assessment of reef fish assemblages of the Southeast FRT for future analyses.