The occurrence of smectite-illite and smectite-chlorite minerals series was studied along a thick clay cap (~300 m) drilled in the Cerro Pabellón geothermal field (northern Andes, Chile). X-ray diffraction (XRD) and scanning electronic microscopy (SEM) were used to characterize the alteration mineralogy and clay mineral assemblages and their changes with depth. Cerro Pabellón is a high-enthalpy blind geothermal system, with a reservoir zone from ~500 m to 2000 m depth, with temperatures of 200–250°C. Three main hydrothermal alteration zones were identified: (1) argillic; (2) sub-propylitic, and (3) propylitic, with variable amounts of smectite, illite-smectite, chlorite-smectite, mixed-layer chlorite-corrensite, illite and chlorite appearing in the groundmass and filling amygdales and veinlets. Chemical and XRD data of smectites, I-S and illites show, with some exceptions, a progressive illitization with depth. The evolution of I-S with depth, shows a sigmoidal variation in the percentage of illite layers, with the conversion of smectite to R1 I-S at ~180–185°C. These temperatures are greater than those reported for other similar geothermal fields and might indicate, at least in part, the efficiency of the clay cap in terms of restricting the circulation of hydrothermal fluids in low-permeability rocks. Our results highlight the importance of a better understanding of clay-mineral evolution in active geothermal systems, not only as a direct (or indirect) way to control temperature evolution, but also as a control on permeability/porosity efficiency of the clay cap.

Wetland restoration can be measured over time using community vegetation as an effectiveness indicator of restoration actions. Spencer Island Regional Park is part of the tidal freshwater wetlands along the Snohomish river basin. Those wetlands are part of a complex ecosystems, in which they are included as a salmon corridor. This research analyzes the vegetation community changes over time after restored in 1996 on Spencer Island Regional Park, Everett, Washington State, U.S. I analyzed three spectral indices using segmentation and supervised classification of land cover from 1997 to 2018. I found that in the last 21 years, the areas with emergent palustrine vegetation and forests increased, in contrast to diminishing areas of upland and scrub-shrub classes. Those finds can be interpreted that the community vegetation advanced to higher wetland successional stages as upland areas have been colonized by emergent wetland plant communities. A linear regression model predicted that by 2025, the difference between emergent and upland classes should increase. Empirical evidence is presented that support the integration of spectral indices to identify changes in community vegetation. However, it is recommended for future studies to include spectral indices and spatial information for soil and hydrology to deepen these results.

El bosque templado lluvioso valdiviano es considerado una de las ecorregiones más relevantes a nivel mundial debido a su importancia biológica. Sin embargo, sus bosques han sido constantemente sometidos a intervenciones antropogénicas, afectando su funcionalidad, composición y estructura, llevándolo a ser altamente prioritario de recuperar. Debido a lo anterior, se determinaron zonas prioritarias para la recuperación de bosque nativo intervenido del bosque templado lluvioso valdiviano en la Región de Los Ríos. En primera instancia, se realizó una revisión de criterios ecológicos discutidos en la literatura, los cuales fueron seleccionados según su aplicabilidad al área de estudio y a la disponibilidad de coberturas para su espacialización. Posteriormente, tales criterios se valoraron y jerarquizaron mediante la aplicación de cuestionarios a diferentes expertos en ecología y conservación de bosques nativos. Luego, esta información fue integrada a un modelo de evaluación multicriterio a partir de sistemas de información geográfica, permitiendo generar un mapa de sitios prioritarios. De acuerdo con los juicios de expertos, los principales criterios son: riqueza de especies en categoría de conservación y el tamaño de la unidad de análisis. Se identificaron 31 sitios prioritarios, abarcando una superficie total de 6.582 hectáreas, concentrados en la comuna de Panguipulli. Finalmente, los sitios identificados proporcionan una primera aproximación para dirigir y evaluar acciones de recuperación. Sin embargo, para que estas acciones sean efectivas, se recomienda incorporar otras dimensiones, buscando soluciones locales, considerando una estrategia de financiamiento y la dinámica natural del bosque.