O trabalho apresenta resultados de um estudo sobre a influência da mata ciliar na análise qualitativa e dados quantitativos de água, em três pontos pertencentes à bacia do Ribeirão Lajeado-TO, cuja área é de 612,77 Km2. Os três pontos delimitados para a realização do estudo foram: Trecho do Ribeirão Lajeado (Ponto 1) com 22,09% de mata ciliar; Córrego Brejo da Passagem (Ponto 2) com 14,80% e Contribuinte do Ribeirão Lajeado (Ponto 3) com 49,08%. O objetivo principal do estudo foi avaliar a influência da mata ciliar na qualidade da água na bacia do Ribeirão Lajeado. Os dados estatísticos descritivos, mostraram que os três pontos no período chuvoso apresentaram flutuações significativas de algumas variáveis analisadas. O ponto 3, bacia mais preservada, apresentou gradientes maiores de temperatura, nitrogênio inorgânico dissolvido, pH e froude. Os pontos 1 e 2, as bacias consideradas menos conservadas, mostraram maiores flutuações das variáveis, no mesmo período amostral. O ponto 1 apresentou variações dos valores de sólidos totais dissolvidos, condutividade, transparência e nitrogênio orgânico relativamente mais altas. No ponto 2, a vazão apresentou valor mais elevado. A turbidez, nitrogênio total, sólidos totais, matéria orgânica, alcalinidade, oxigênio dissolvido tiveram também valores elevados neste ponto. O fosfato apresentou variações similares nos pontos 1 e 2. Durante o período seco, nota-se que o ponto 1 apresentou variações maiores nas concentrações de temperatura, condutividade, sólidos totais dissolvidos e transparência. A turbidez, pH, alcalinidade, nitrogênio inorgânico dissolvido, sólidos totais, matéria orgânica e Froude, demonstraram um gradiente relativamente alto no ponto 2. As concentrações das variáveis oxigênio dissolvido, nitrogênio (orgânico e total) e a vazão, apresentaram valores mais altos no ponto 3. A variável fosfato mostrou valores similares em todos os pontos. Os resultados de forma geral na análise de componentes principais demonstraram tendências para dois gradientes, temporal e espacial. No gradiente temporal, foi verificada a segregação dos períodos chuvoso e seco, onde foi analisado o comportamento das variáveis em ambos e no gradiente espacial observou -se a correlação entre os pontos e campanhas adotadas e o desempenho das variáveis físicas, químicas e hidrológicas. Em relação a dinâmica do carbono orgânico total e o carbono inorgânico dissolvido, pode evidenciar respostas mais significantes no período chuvoso, com valores mais expressivos nos pontos 1 e 2. No período seco analisado, observou-se que o ponto 3, apresentou valores mais elevados de carbono orgânico total, e o ponto 1 de carbono inorgânico dissolvido. De acordo com os resultados de outros testes estatísticos aplicados de forma integrada nos dois períodos analisados, verificou-se relações positivas entre: CND x STD; Zsd x Q; OD x Q e MO x ST, no ponto 1. Ainda no Ponto 1 os testes demonstraram correlação negativa nas relações OD x Froude e OD x STD. No ponto 2, verificou-se relações diretamente proporcionais entre as variáreis: T x Q; Zsd x Q; OD x Q; CND x STD e MO x ST. No ponto 3 observou-se também relações positivas entre as variáveis, T x Q; CND x STD e MO x ST; e relações negativas entre STD x (Froude e Q). Com relação ao comportamento hidrológico, especificadamente a vazão especifica, nos respectivos pontos estudados observou-se que o percentual de cobertura de mata ciliar no ponto 3, influenciou positivamente nos resultados dessa variável, no período seco. No período chuvoso, notou-se que os dados apresentaram valores relativamente mais baixos no mês de março. Os pontos 1 e 2, consideradas as bacias com menores percentuais de mata ciliar, demonstraram comportamentos diferentes nos resultados de vazões especificas. No período chuvoso as vazões especificas, com exceção do ponto 2 em parte do período de abril a maio, foram elevadas, o que possivelmente pode estar associado ao aumento do escoamento superficial neste período. Notou-se, entretanto, que no período seco, esses valores sofreram um decréscimo bastante significativo. De maneira geral para avaliar a possível influência da mata ciliar na qualidade da água, outros estudos devem ser realizados e aprofundados considerando características peculiares do ciclo hidrológico local, bem como monitoramento do transporte e deposição de sedimentos e a caracterização dos ciclos de nutrientes na água e nos ecossistemas de mata ripária, além de uma cuidadosa caracterização e quantificação das alterações no uso do solo. | The paper presents results of a study on the influence of riparian vegetation in qualitative and quantitative data of water at three points belonging to the basin of Lajeado stream-TO, whose area is 612.77 km2. The three points chosen for the study were: stretch of Lajeado steam (Point 1) with 22.09% of riparian vegetation; brejo da Passagem stream (Point 2) with 14.80% and Coducive of Lajeado stream (Point 3) with 49.08%. The main objective of the study was to assess the influence of riparian vegetation on water quality in the Lajeado stream basin. Descriptive statistics data showed that the three points in the wet season showed significant fluctuations of some variables analyzed. Point 3 is more preserved basin, showed higher gradients of temperature, dissolved inorganic nitrogen, pH, and Froude. Points 1 and 2 basins considered less conserved, showed greater fluctuations of the variables in the same sample period. Point 1 showed variations in the values of total dissolved solids, conductivity, transparency and relatively higher organic nitrogen. In point 2, the flow were higher. Turbidity, total nitrogen, total solids, organic material, alkalinity, dissolved oxygen values were also high at this point. Phosphate showed similar variations in 1 and 2. During the dry season, it was noted that in point 1 showed greater variations in the concentrations of temperature, conductivity, total dissolved solids and transparency. Turbidity, pH, alkalinity, dissolved inorganic nitrogen, total solids, organic matter and Froude, showed a relatively high gradient in point 2. The concentrations of variables dissolved oxygen, nitrogen (organic and total) and flow, were higher in point 3. The variable phosphate showed similar values at all points. The results generally in principal component analysis showed trends for two gradients, temporal and spatial. In the temporal gradient, there was segregation of the rainy and dry season, where was studied the behavior of both variables. In the spatial gradient it was observed correlation between points and campaigns adopted and performance of physical variables, chemical and hydrological . Concerning the dynamics of total organic carbon and dissolved inorganic carbon, may show the most significant responses in the rainy season, with higher values in point 1 and 2. In the dry period analyzed, it was noted that the point 3 had higher values for total organic carbon, and the point 1 of dissolved inorganic carbon. According to the results of other statistical tests applied in an integrated way in the two study periods analyzed, it was found positive relationships between: CND x STD; ZSD x Q; OD x Q and MO x ST in point 1. Still in Point 1, the tests showed a negative correlation in the relationship OD x Froude and OD x STD. In Point 2, it was observed that there was directly proportional relationship between the varied: T x Q, ZSD x Q; OD x Q; CND x STD end MO x ST. Point 3 was also observed positive relationships between the variables, T x Q; CND x STD and MO x ST and negative relationships between STD x (Froude and Q). With regard to hydrology, specifically the flow specifies, in their points studied it was observed that the percentage coverage of riparian vegetation in point 3, positively influenced the results of that variable in the dry period. In the rainy season, it was noted that the data showed relatively lower values in March. Points 1 and 2, considering the basins with smaller percentages of riparian vegetation, showed different behaviors on the results of specific flow rates. In the rainy season the specific flows, with the exception of point 2 in part the period from April to May, were high, which possibly can be associated with increased outflow superficial in this period. It was noted, however, that in the dry season, these values have undergone a fairly significant decrease. Generally to assess the possible influence of riparian vegetation on water quality, further studies should be conducted and detailed considering the peculiar characteristics of local hydrological cycle, as well as monitoring the transport and deposition of sediments and the characterization of the nutrient cycles in water and riparian forest ecosystems, beyond of a careful characterization and quantification of changes in land use.

Uruguay has a dense hydrographic network, nevertheless the knowledge of the aquatic macroinvertebrate community is still lacking. In recent decades afforestation with exotic species has increased which has produced changes in riparian vegetation of some rivers. The aim of this research was to determine the composition and trophic structure of macroinvertebrate community and its relationship to some physicochemical parameters in eight streams where the native forest is still well preserved and provide the basis for future studies. Samples were collected from December 2006 to December 2007. Temperature, dissolved oxygen, pH and conductivity were measured in situ. Taxonomic composition and abundance were determined, a principal component analysis and a canonical correspondence analysis were carried out with the physico-chemical and biological parameters. The alpha diversity was calculated using the Shannon-Weaver (H'), dominance of Simpson (D) and Pielou evenness indexes (J'). Beta diversity was determined employing similarity index of Bray-Curtis. A total of 1 291 specimens belonging 92 taxa were recorded. The most abundant taxa were Ephemeroptera (36%), Amphipoda (17%) and Coleoptera (12%). The streams show high diversity and low dominance. Conductivity, pH, and temperature were the main factors in determining the macroinvertebrate distribution and composition.

River sediments have the capability to accumulate and absorb traces of anthropic environmental degradation. In this work, we investigated the effects of urban land use on the composition of physical sediment. For this purpose, sediment profiles were collected in the wet and dry seasons and in locations with mixed land-use. For the sediment analysis, particle size separation, organic matter degradation, visual analysis of the thickest fraction using a magnifying glass and stereomicroscope analysis of the particle size material corresponding to the sands were performed. It was observed that the sedimentation of synthetic materials and plastics (fragments and fibres) were the most frequently found materials. More intense urban occupation areas and with less riparian vegetation suffer more from this degradation than rural areas or areas with preserved riparian vegetation. The dam in the basin accumulates more materials (macro and microplastics) and has the role of containing and preventing these residues from being transported downstream. The importance of investing in environmental management measures is emphasized, and based on the sampled sites assessed, the restoration of riparian vegetation, greater inspection of inadequate waste disposal and public cleaning actions are suggested, including actions in the Tibiriçá dam.

Se comentan los efectos de una utilizacion intensiva de los rios por parte del hombre y los motivos para su restauracion, atendiendo a los recursos y valores que ofrecen. La agricultura supone una actividad de gran repercusion economica, a escala mundial, y requiere grandes inversiones para el aprovechamiento de los recursos hidricos, teniendo un gran impacto tanto en la gestion de cuencas vertientes, como en la de los sistemas fluviales propiamente dichos. Las tecnicas de restauracion de los rios afectados por la agricultura deben estar basadas en estrategias de "bio-asimilacion", donde se plantea el establecimiento de bandas protectoras de vegetacion riparia ("buffer strips") a lo largo de su trazado.

Two contrasting sites along Huehueyapan River (Veracruz, Mexico), one relatively conserved and the other one impacted by domestic and coffee mill discharges, were compared based on water quality data, and the structure of the Odonata larval assemblages. Riparian vegetation of both sites was differentially modified or replaced. Physical and chemical parameters and Odonata larvae were gathered from January to November 2001. A Hotelling-T test was used to compare the physico-chemical parameters while rank/abundance graphs and Renyi diversity profiles were constructed using Odonata larvae data. A total of 2,212 larvae of 13 species in 7 genera were collected. The sites were very similar in number of species and Odonata larval assemblage structure, however, some of the most abundant species at both sites showed significant differences in abundance. The observed differences between the 2 sites are mainly explained by differences in the structure of riparian vegetation and the availability of substrates for odonates and, secondarily, by physical and chemical changes in the water. An abundance ratio was established based on the most abundant species for monitoring future impairment or recovery changes.

Resumen: Se compararon, en términos de calidad del agua, la estructura del ensamblaje de larvas de odonatos y el grado de modificación de la vegetación ribereña, en 2 sitios contrastantes del río Huehueyapan (Veracruz, México), uno poco perturbado y otro impactado por descargas domésticas y de un beneficio de café. Se midieron diferentes parámetros físicos y químicos y se recolectaron las larvas de odonatos de enero a noviembre de 2001. Para comparar los sitios por sus variables físicas y químicas se usó una T de Hotelling y para los datos de abundancia de larvas se construyeron curvas de dominancia/diversidad y perfiles de diversidad de Renyi. Se recolectaron 2,212 larvas de 13 especies y 7 géneros. Los sitios resultaron similares en riqueza y estructura de sus ensamblajes, aunque algunas especies dominantes en ambos sitios mostraron diferencias significativas en abundancia, lo que evidencia un establecimiento diferencial en ambos sitios. Las diferencias se explican principalmente por la estructura de la vegetación ribereña y la disponibilidad de sustratos adecuados para los odonatos y, secundariamente, por los cambios físicos y químicos del agua. Se creó una proporción de abundancia para la vigilancia de futuros cambios por deterioro o por recuperación con base en las especies más abundantes. | Abstract: Two contrasting sites along Huehueyapan River (Veracruz, Mexico), one relatively conserved and the other one impacted by domestic and coffee mill discharges, were compared based on water quality data, and the structure of the Odonata larval assemblages. Riparian vegetation of both sites was differentially modified or replaced. Physical and chemical parameters and Odonata larvae were gathered from January to November 2001. A Hotelling-T test was used to compare the physico-chemical parameters while rank/abundance graphs and Renyi diversity profiles were constructed using Odonata larvae data. A total of 2,212 larvae of 13 species in 7 genera were collected. The sites were very similar in number of species and Odonata larval assemblage structure, however, some of the most abundant species at both sites showed significant differences in abundance. The observed differences between the 2 sites are mainly explained by differences in the structure of riparian vegetation and the availability of substrates for odonates and, secondarily, by physical and chemical changes in the water. An abundance ratio was established based on the most abundant species for monitoring future impairment or recovery changes.