Land use changes affect water quality and chlorophyll concentration in tropical streams

Background: Forest conversion to agriculture and pasture that has occurred in the last decades southern Mexico can affect ecological functioning of rivers streams. Objective: investigate how land use change at different scales (catchment riparian zone) influences water quality benthic chlorophyll streams Chiapas Tabasco mountains. Methods: Over a period 13 months, physicochemical variables were measured, samples collected for determination nutrients, suspended solids, eight encompassing cover Puyacatengo, Pichucalco, Teapa sub-basins Grijalva watershed. The study statistically compared among categories seasons relationship with was analyzed. Results: Streams draining forested areas showed lower temperature, conductivity, pH, phosphorus concentrations than mixed categories. also greater proportion organic matter dissolved oxygen concentration more disturbed Temporal dispersion values stream forest sites mixed-land Variation related catchment (forest, pasture, secondary vegetation) (pasture scales. Conclusions: Land changes mountains Chiapas, thus conservation restoration actions, including reforestation, must be implemented both