Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir / Morfometria e tempo de residência como fatores determinantes no estabelecimento e manutenção de macrófitas aquáticas em um reservatório tropical

Abstract Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather than trophic status and depth of the euphotic zone. In this context, this study aimed at describing and comparing the incidence of aquatic macrophytes in a throughflowing, non-dendritic tropical reservoir. During February 2006 to November 2007, eight limnological surveys were performed quarterly within the Ourinhos Reservoir, and in the mouth areas of its tributaries. At the six sampling stations 30 variables were measured. The number of sites with plants varied between 21 and 38 and at the end of the 1st year the total richness was found. The sampling survey outcome the recognition of 18 species of aquatic macrophytes; Cyperaceae (2 genera and 1 species), Pontederiaceae (3 species) and Onarograceae (3 genera) were the families with higher diversity. Seven species (Typha domingensis Pers., Myriophyllum aquaticum (Vell.) Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw.) Kunth, Eleocharis sp1, Eichhornia crassipes (Mart.) Solms, Oxycaryum cubense (Poepp. & Kunth) Lye) always were present and were more frequent in the sites. The occurrence of emergent species predominated (45.9%), followed by submersed rooted (24.5%), free floating (19.5%), floating rooted (9.7%) and free submersed (0.3%). Although limnological variables and the distribution of macrophytes have discriminated the same sampling points, the stepwise multiple linear regressions did not pointed out strong correspondences (or coherence) among the most constant and distributed macrophyte species and the selected limnological variables, as well the trophic statuses. Seeing the low relationship among limnological variables and macrophytes distribution, in the case of Ourinhos Reservoir, the results pointed out that the water turbulence, low DL and wind exposure are the main driving forces that determine its aquatic plant distribution, life forms and species composition.

Resumo As macrófitas podem constituir um recurso importante para vários processos físicos, químicos e biológicos dos ecossistemas aquáticos. Esse estudo considera que nos reservatórios tropicais com baixo tempo de retenção e com baixos valores do grau de desenvolvimento das margens (DL), a expansão e manutenção das macrófitas aquáticas são referidas principalmente às condições locais (e.g., hidrodinâmica e exposição ao vento), ao invés do estado trófico e da profundidade de zona eufótica. Nesse contexto, o presente estudo teve como objetivo descrever e comparar a incidência de macrófitas aquáticas em um reservatório tropical de fluxo rápido e não dendrítico. De fevereiro de 2006 a novembro de 2007, oito avaliações limnológicas foram realizadas trimestralmente no reservatório Ourinhos e nas regiões de desembocadura de seus afluentes. Nas seis estações de amostragem 30 variáveis foram determinadas. O número de locais com plantas variou entre 21 e 38 e no final do primeiro ano o número total de espécies foi encontrado. Foram relacionadas 18 espécies de macrófitas aquáticas; Cyperaceae (2 gêneros e espécies), Pontederiaceae (3 espécies) e Onarograceae (3 gêneros) foram as famílias com mais diversidade. Sete espécies (Typha domingensis Pers., Myriophyllum aquaticum (Vell.) Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw.) Kunth, Eleocharis sp1, Eichhornia crassipes (Mart.) Solms, Oxycaryum cubense (Poepp. & Kunth) Lye) sempre estiveram presentes e foram as mais frequentes. As ocorrências de espécies emergentes predominaram (45,9%), seguidas das submersas enraizadas (24,5%), flutuantes livres (19,5%), flutuantes enraizadas (9,7%) e submersas livres (0,3%). Embora as variáveis limnológicas e as distribuições de macrófitas tenham discriminado os mesmo pontos de coleta, regressões lineares múltiplas stepwise não apontaram correspondências fortes (ou coerentes) entre as espécies de macrófitas mais constantes e distribuídas e as variáveis limnológicas, assim como os estados tróficos. No reservatório Ourinhos, a baixa relação entre as variáveis limnológicas e a distribuição das macrófitas aponta que a turbulência da água, o baixo valor de DL e a exposição ao vento sejam as principais forças que determinam a distribuição das plantas aquáticas, as suas formas de vida e a composição das espécies.

Public green areas and urban environmental quality of the city of São Carlos, São Paulo, Brazil / Áreas verdes públicas e a qualidade ambiental urbana do Município de São Carlos, Estado de São Paulo, Brasil

Abstract Assess the state of public green areas, their importance and influence on environmental quality and living in urban centers is an arduous task considering the conceptual and scientific regarding quantification and data analysis methods divergence. In this study, we aimed to determine two indicators of public green areas relative to the percentage of public green areas (PPGA) and the public green areas index (PGAI) in the urban area of São Carlos, SP. The study area was organized into administrative regions (ARs), using satellite images, topographical maps of 1:10,000 Geographic and Cartographic Institute (1990) and data provided by the Municipality of São Carlos. The results show that public green areas comprise 6.55% of the municipality, with a public green areas index (PGAI) of 18.85 m2/inhabitant, indicating good urban environmental quality when compared to rates of 15 m2/capita for public green areas for recreation, suggested by the Brazilian Society of Urban Forestry. The differences between the administrative regions are concern with situations from 4.16 to 36.30 m2/inhabitant. In this context, it is recommend specific public policies and popular participation in the process of continuous improvement for increasing public green areas in the less favored regions. The Genebrino method applied to indicators of public green areas (GPGA – amount of public green areas divided by population density), showed a commendable goal above 40% for urban environmental quality.

Resumo Diagnosticar a situação das áreas verdes públicas, sua importância e influência na qualidade ambiental e de vida nos centros urbanos é uma tarefa árdua, considerando a divergência conceitual e de métodos científicos no que tange a quantificação e a análise dos dados. Neste estudo, objetivou-se determinar dois indicadores de áreas verdes públicas, referentes ao percentual de áreas verdes públicas (PAVP) e ao índice de áreas verdes públicas (IAVP) no perímetro urbano do Município de São Carlos, SP. A área de estudo foi organizada em regiões administrativas (RAs), utilizando imagens de satélite, cartas topográficas 1:10.000 do Instituto Geográfico e Cartográfico (1990) e dados fornecidos pela Prefeitura Municipal de São Carlos. Os resultados demonstram que as áreas verdes públicas compreendem 6,55% do território do município, com um índice de áreas verdes públicas (IAVP) de 18,85 m2/habitante, indicando uma boa qualidade ambiental urbana quando comparado aos índices de 15 m2/habitante para áreas verdes públicas destinadas à recreação, sugerido pela Sociedade Brasileira de Arborização Urbana. As diferenças entre as regiões administrativas são preocupantes, com situações de 4,16 a 36,30 m2/habitantes. Neste contexto, recomendam-se políticas públicas específicas e a participação popular no processo de melhoria contínua para o incremento das áreas verdes públicas nas regiões menos favorecidas. O método genebrino, aplicado aos indicadores de áreas verdes públicas (IAVP – somatório das áreas verdes públicas dividido pela densidade populacional), apontou uma meta recomendável acima de 40% para a qualidade ambiental urbana.

Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir.

Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather than trophic status and depth of the euphotic zone. In this context, this study aimed at describing and comparing the incidence of aquatic macrophytes in a throughflowing, non-dendritic tropical reservoir. During February 2006 to November 2007, eight limnological surveys were performed quarterly within the Ourinhos Reservoir, and in the mouth areas of its tributaries. At the six sampling stations 30 variables were measured. The number of sites with plants varied between 21 and 38 and at the end of the 1st year the total richness was found. The sampling survey outcome the recognition of 18 species of aquatic macrophytes; Cyperaceae (2 genera and 1 species), Pontederiaceae (3 species) and Onarograceae (3 genera) were the families with higher diversity. Seven species (Typha domingensis Pers., Myriophyllum aquaticum (Vell.) Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw.) Kunth, Eleocharis sp1, Eichhornia crassipes (Mart.) Solms, Oxycaryum cubense (Poepp. & Kunth) Lye) always were present and were more frequent in the sites. The occurrence of emergent species predominated (45.9%), followed by submersed rooted (24.5%), free floating (19.5%), floating rooted (9.7%) and free submersed (0.3%). Although limnological variables and the distribution of macrophytes have discriminated the same sampling points, the stepwise multiple linear regressions did not pointed out strong correspondences (or coherence) among the most constant and distributed macrophyte species and the selected limnological variables, as well the trophic statuses. Seeing the low relationship among limnological variables and macrophytes distribution, in the case of Ourinhos Reservoir, the results pointed out that the water turbulence, low DL and wind exposure are the main driving forces that determine its aquatic plant distribution, life forms and species composition.

Public green areas and urban environmental quality of the city of São Carlos, São Paulo, Brazil.

Assess the state of public green areas, their importance and influence on environmental quality and living in urban centers is an arduous task considering the conceptual and scientific regarding quantification and data analysis methods divergence. In this study, we aimed to determine two indicators of public green areas relative to the percentage of public green areas (PPGA) and the public green areas index (PGAI) in the urban area of São Carlos, SP. The study area was organized into administrative regions (ARs), using satellite images, topographical maps of 1:10,000 Geographic and Cartographic Institute (1990) and data provided by the Municipality of São Carlos. The results show that public green areas comprise 6.55% of the municipality, with a public green areas index (PGAI) of 18.85 m2/inhabitant, indicating good urban environmental quality when compared to rates of 15 m2/capita for public green areas for recreation, suggested by the Brazilian Society of Urban Forestry. The differences between the administrative regions are concern with situations from 4.16 to 36.30 m2/inhabitant. In this context, it is recommend specific public policies and popular participation in the process of continuous improvement for increasing public green areas in the less favored regions. The Genebrino method applied to indicators of public green areas (GPGA - amount of public green areas divided by population density), showed a commendable goal above 40% for urban environmental quality.

Vegetation coverage in hydrographic basins in the central region of the State of São Paulo, Brazil.

Vegetation coverage can be inappropriately used, especially in the absence of proper planning, and can result in a reduction of the occupied area. Demographic and economic alterations are factors that contribute to the degradation of vegetation coverage in landscape units. In addition, because vegetation is essential for protection of recharge areas in aquifers, the fragmentation of habitats in hydrographic basins causes changes in climate temperature, soil erosion, eutrophication, and siltation of watercourses. This study analyzed the vegetation coverage from the municipality of São Carlos, State of São Paulo (SP) to assess the environmental quality of water resources in the hydrographic basins and sub-basins, in the Guarani Aquifer System. The vegetation coverage was analyzed in three scales: municipality, Hydric Resource Management Units (UGRHIs), and hydrographic sub-basins based on map overlapping from the LAPA/UFSCar Digital Cartographic Collection and visual interpretation of LANDSAT 5, TM sensor, Path 220, row 075 on satellite images. The municipality of São Carlos has vegetation coverage of 31,776.4 hectares, in which 57% is classified as preserved vegetation typology, and 58% is over the Guarani aquifer recharge area. The vegetation coverage with savannas, riparian forests, and mesophyll forests represented 28% of the total studied area and is located over 28.3% of the Guarani aquifer recharge area extension. The Permanent preservation areas (PPAs) represent 21.6% of the total vegetation coverage with 51% of it being vegetated. The municipality has a total of 686 springs (Topographic maps of IBGE, escale 1:50,000) distributed on an average of 60 springs per km2; 40% of these are protected by vegetation.