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This article relates epilithic dry- and wet-seasonal bacterial biofilm composition to water quality along Río de la Sabana near Acapulco, Mexico. Samples were taken from various locations including nearly pristine upland locations, adjacent to residential floodplain developments, and immediately upstream from an estuarine lagoon. Bacterial composition was identified through sequential DNA analysis at the phylum, class, order, and family levels, with most of these categorized as heterotrophs, autotrophs, denitrifiers, nitrogen fixers, pathogens, and/or potential bioremediators based on generalized literature-sourced assignments. The results were interpreted in terms of location by extent of effluent pollution, and by dry versus wet seasonal changes pertaining to biofilm composition, related bacterial functions, and the following water quality parameters: temperature, pH, dissolved oxygen, biological and chemical oxygen demand, fecal and total bacteria counts, methylene blue active substances, electrical conductivity, and nitrite, nitrate, ammonium, sulfate, and phosphate concentrations. It was found that epilithic bacterial biofilm diversity was richest during the wet season, was more varied in abundance along the upland locations, and was dominated by Proteobacteria and Bacteroidetes with bioremediation and pathogen functions along effluent-receiving river locations. Low-abundance families associated with anaerobic and denitrifying functions were more prevalent during the wet season, while low-abundance families associated with aerobic, N2-fixing and pH-elevating functions were more prevalent during the dry season.

Los árboles capturan y almacenan grandes cantidades de carbono en su biomasa e impactan positivamente en la mitigación de los gases de efecto invernadero (GEI). Hasta esta fecha, no existen ecuaciones alométricas que estimen la biomasa de árboles del estado de Guerrero, México. El presente trabajo tuvo como objetivo generar ecuaciones para estimar la biomasa aérea de árboles de Pinus oocarpa Schiede y Quercus resinosa Liebmann. Se realizó un muestreo destructivo de 33 árboles para la primera especie y 19 para la segunda, distribuidos en el bosque templado de la microcuenca del río Hueyapa, Guerrero, México. La biomasa de los componentes del árbol se estimó con base en el peso seco de 6 a 14 muestras por componente arbóreo, según el tamaño del árbol. Se ajustaron modelos potenciales en su forma lineal y con transformación Box-Cox. El modelo que mejor estimó la biomasa aérea en P. oocarpa fue el potencial y para Q. resinosa fue el que se obtuvo con la transformación Box-Cox, usando logaritmo del diámetro normal ( ) y la variable combinada transformada  como variable independiente. Las ecuaciones alométricas generadas rellenan el vacío existente para la estimación de la biomasa aérea de estas especies forestales en el estado de Guerrero.

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Models based on multifactorial interactions are needed to deal with the dynamics taking place in the eutrophication processes of coastal lagoons. However, as the number of indirect drivers stemming from anthropogenic factors increases, temporal disorders between anthropogenic activities may increase, thus hindering the understanding of their dynamics. We have built multifactorial pathways to deal with the dynamics associated with the cultural eutrophication process of a coastal lagoon. The pathways guided the identification of potential temporal disorder patterns between anthropogenic activities, which may exert influence on the disturbances associated with eutrophication process. The identification of temporal disorder patterns derived from anthropogenic activities belonging to different pathways resulted in a valuable form of support for analyzing and evaluating relationships between public policies, technological skills and environmental culture programs. All of which exert influence on the eutrophication process, which in turn cause changes on the trophic state and on the landscape of the coastal lagoon. Pathways composed of multifactorial interactions that take into account spatial and temporal aspects, contribute to improving the understanding of the inherent dynamics of the eutrophication process of coastal lagoons. Temporal disorders between anthropogenic activities may be seen to emerge, thus exerting changes on the trophic state and spatial damage on the landscapes of coastal lagoons.