Recebido em 12/7/99; aceito em 21/1/00 INFLUENCE OF CATTLE RANCHING AND AGRICULTURAL ACTIVITIES ON PHYSICAL CHEMICAL PARAMETERS OF WATER. Water Quality Index (WQI) was used during summer and winter of 1994 and 1995 in the final section of Onça and Feijão streams, downstream BroaReservoir (São Carlos/SP) to evaluate agricultural and catlleman effects. In Onça stream water quality was ″acceptable″ in winter and ″inappropriate to conventional treatment″ in the summer. In Feijão stream the water had an ″excellent″ quality in winter and ″good″ in the summer. A MANOVA (Multivariate Analysis of Variance) has used to discriminate seasons and streams. Correlation (p<0,05) among the variables was tested. Water temperature, turbidity, pH and fecal bacteria are highly correlated and can be one of the factors that cause WQI change by seasons.Keywords: water quality; grazing; agriculture; limnology; physic-chemical parameters. ARTIGO INTRODUÇÃOA agricultura e a pecuária são atividades econômicas indispensáveis na produção de alimentos. Contudo, a deposição de resíduos agrícolas e animais têm resultado em alterações ambientais que desde a década de 60 já são avaliadas nos Estados Unidos 1-3 . Tanto a agricultura como a pecuária têm uma necessidade imediata: o espaço físico. Isto faz do desmatamento a primeira conseqüência prejudicial ao ambiente. Com isto o solo desnudo fica exposto à lixiviação superficial (que leva consigo a deposição orgânica de vegetais e sua microfauna associada) e à lixiviação profunda (que promove uma lavagem dos nutrientes nas camadas subsequentes); tais processos resultam em empobrecimento do solo e conduzem o material para áreas mais baixas, que em geral convergem para rios e lagos, que pode acarretar aumento no uso de fertilizantes, desequilibrando o conteúdo de nutrientes no solo e expondo-o à contaminação química.A criação de pastagens diminui a diversidade vegetal local (por se tratar de uma monocultura) e a diversidade animal (pois homogeneiza o ambiente e poucas espécies, quando não apenas uma, conseguem se adaptar). A intensidade de forrageamento compromete a manutenção e regeneração do sistema florestal (devido ao pisoteio) 4-5 de forma que a vegetação arbustiva é lentamente substituída pela herbácea que pode diminuir em diversidade com a predação [6][7] . Também a manutenção de pastos e o pisoteio propiciam o empobrecimento em nutrientes do solo e facilitam a erosão 8 . Com a homogeneização do ambiente, muitos predadores naturais de parasitas inicialmente emigram e produtos químicos são então usados para o controle de patógenos.Uma segunda prioridade para agricultura e pecuária é o suprimento de água, o que conduz ao desenvolvimento destas atividades próximo à rios e lagos. Atividades de forrageamento intensivo ou semi-intensivo bem como o manejo agrí-cola com uso de produtos que visam aumento de produção, gradualmente desgastam o solo exposto à escorrimentos superficiais da água da chuva ou até erosões profundas. Nos dois casos há uma entrada adicional de material edáfico (componentes do so...

BackgroundIn small-scale fishery, information provided by fishers has been useful to complement current and past lack of knowledge on species and environment.MethodologyThrough interviews, 82 fishers from the largest fishing communities on the north and south borders of a Brazilian northeastern coastal state provided estimates of the catch per unit effort (CPUE) and rank of species abundance of their main target fishes for three time points: current year (2013 at the time of the research), 10, and 20 years past. This information was contrasted to other available data sources: scientific sampling of fish landing (2013), governmental statistics (2003), and information provided by expert fishers (1993), respectively.Principal FindingsFishers were more accurate when reporting information about their maximum CPUE for 2013, but except for three species, which they estimated accurately, fishers overestimated their mean CPUE per species. Fishers were also accurate at establishing ranks of abundance of their main target species for all periods. Fishers' beliefs that fish abundance has not changed over the last 10 years (2003–2013) were corroborated by governmental and scientific landing data.ConclusionsThe comparison between official and formal landing records and fishers' perceptions revealed that fishers are accurate when reporting maximum CPUE, but not when reporting mean CPUE. Moreover, fishers are less precise the less common a species is in their catches, suggesting that they could provide better information for management purposes on their current target species.

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Aim Protected areas are frequently defined on the basis of biological importance. Ecosystem services are expected to be under protection when biodiversity is preserved; however, new approaches are needed to confirm this statement. We evaluated how spatial associations between ecosystem services and plant biodiversity on a large spatial scale influence their representativeness in current protected areas. Location Brazilian seasonally tropical dry forest (Caatinga). Methods We produced woody plant biodiversity maps (species richness, narrow‐range species richness and beta diversity) using species distribution modelling. We estimated regulating services (water purification, carbon storage and erosion control), provisioning services (water supply, fodder and agriculture) and supporting services (water balance, net primary productivity and soil fertility) using primary data and a proxy‐based approach. We performed spatial correlation analyses between biodiversity and ecosystem services using Pearson's correlation test. After estimating the percentage of hotspot areas of biodiversity and ecosystem services presented in two types of protected areas (strict protection and sustainable use), we compared it to expected distribution by null model. Results Mostly weak and intermediary positive correlations arose among biodiversity and ecosystem services (beta diversity with water balance and species richness with water purification and carbon storage). Negative correlations occurred among water balance with both species richness and narrow‐range species richness. Strict protection areas were well represented in terms of carbon storage and underrepresented for fodder and agriculture. Sustainable use protected areas were important for water balance. Plant biodiversity variables were not represented in current protected areas. Main conclusions Positive correlations between biodiversity and ecosystem services do not assure the protection of these targets in protected areas. Surrogates choice based only on spatial correlations might not effectively protect biodiversity and ecosystem services. Selection of priority areas must include biodiversity and ecosystem services as distinct conservation targets.

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