Environmental quality contributes to the physical and mental well-being of the population. In this way, the green areas (GA) of the cities are essential spaces for coexistence, sports, socialization, recreation, among others. The objective of this research was to determine the environmental conditions of green areas, using indicators as tool for urban management in two cities of Costa Rica. The study area corresponded to the districts of Heredia and Carmen, Costa Rica. The existing GA were determined using Rapid Eye satellite images, 2 012 through spatial analysis and remote sensing. Eleven indicators of urban green areas were applied, the species was identified, the height, the diameter at breast height (DBH) and the number of trees in parks and streets were measured. In addition, surveys were conducted to users of public GA, on issues related to accessibility and use of GA. Five types of GA were identified in Carmen and six were located in Heredia. The percentage of public and private green areas corresponded to 36 % and 64 % in Carmen and 13 % and 87 % in Heredia respectively. The green area per capita (m2 / hab) was 24.6 in Carmen and 2.7 in Heredia. Sixty-two species of trees were identified in the Carmen parks and 23 in Heredia. There were 1 105 trees of 61 species in the streets, sidewalks and avenues of Carmen and 278 individuals of 47 species in Heredia. Regarding the existence of riparian vegetation, it was determined that the Pirro, Burrio, Torres and Negritos streams maintain 82 %, 51 %, 81 % and 14 % of the area of protection of their margins in conforming use. 11 of the public GA’s were evaluated, nine presented a high physical accessibility. In both districts, the surveyed citizens indicated the necessity to have more GA, highlighting the recreational, ecological and touristic value of these spaces. It is concluded that the indicators of urban green areas showed that there are differences between the environmental conditions in both of the evaluated cities. In addition, the applicability of the indicators is feasible as an input for the sustainable environmental management of urban ecosystems.

Abstract:Currently, nitrogen has become the main element of water pollution, causing riverine, lacustrine and coastal eutrophication. The continuous contamination of aquifers and the absence of planned water resource utilization, boost its scarcity, and has been the only way in which our societies become aware of the urgent need to process the generated wastewater. The objective of this research was to evaluate the nitrifying capacity of different autochthonous bacterial isolates from soils from nearby sources of domestic wastewater drainage. For this, bacteria were isolated from Pirro River, contaminated with nitrogen of domestic sewage. Nitrifying bacteria were counted by serial dilution and agar plates, and were isolated until obtaining axenic colonies. These were identified by biochemical batteries or genetic sequencing, and the quantification of their nitrifying capacity was obtained by the methods 4500-NH4 + -F and 4500-NO-2-B, all between September 26, 2011 and March 16, 2014. A total of seven strains of nitrifying microorganisms were isolated and purified, including four Streptomyces sp., one Pseudomonas putida, one Sphingomonas sp. and one Aeromonas sp. We found that there were 2.23 x 10 5 UFC/g of soil of ammonium oxidizing bacteria and 2.2 x 10 4 CFU/g of soil of nitrite oxidizing bacteria in the samples. The quantification of the nitrifying capacity of the strains by colorimetric methods, determined that the maximum ammonium removal capacity was 0.050 mg N/L/day and 0.903 mg N/L/day of nitrite. The collection of few strains of nitrifying organisms and a low CFU count, can be attributed to the technique used, since this only recovers 1 % of the microorganisms present in a sample, which, however, is acceptable for studies which main purpose is to obtain cultivable microorganisms. Future research should consider removal tests with higher ammonium and nitrite levels, to find the maximum capacity of the isolated microorganisms, and evaluate their potential use in wastewater treatment systems. Rev. Biol. Trop. 65 (4): 1527-1539. Epub 2017 December 01.

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La variabilidad climática provoca impactos sobre los ecosistemas marino-costeros, además de la afectación de los recursos naturales, paisajes y las comunidades costeras vinculadas. Tales comunidades pueden adaptarse a estos cambios o convertirse en migrantes climáticos. Este estudio tuvo como propósito evaluar los mecanismos de adaptación de las comunidades costeras del Caribe Sur (CS) de Costa Rica en relación con los impactos de la variabilidad climática sobre los ecosistemas marinos y costeros para la reducción de su vulnerabilidad. Se realizó revisión documental, se aplicaron técnicas de observación no participante y encuestas a pobladores locales. Se realizaron 65 encuestas en las localidades de Gandoca, Manzanillo, Cahuita, Puerto Viejo, del cantón de Talamanca y Limón del cantón de Limón. Entre los principales resultados destacan las actividades económicas registradas, que fueron agricultura de subsistencia, pesca, turismo, comercio y recolección de cocos. Las artes de pesca identificadas fueron buceo a pulmón, caña de pescar, nasas, líneas de palangre y trasmallo. Se identificó que los locales perciben la influencia de la variabilidad climática; por ejemplo, el aumento del nivel del mar debido a que ha afectado la infraestructura (casas, carreteras, puentes) y el aumento de la temperatura atmosférica porque ha impactado la distribución de las especies de peces. Las comunidades locales no cuentan con un plan de acción gubernamental; pero se han adaptado a las nuevas condiciones, implementado acciones como: diversificación del voluntariado, traslado de infraestructura, agricultura orgánica, pesca como actividad económica complementaria y reforestación de la línea costera. Estas comunidades se han adaptado a los cambios presentados por la variabilidad climática, aunque sin planificación, por lo que es necesaria la atención urgente de las autoridades para definir acciones en el futuro.