Cushion plant dominated peatlands are key ecosystems in tropical alpine regions of the Andes in South America. The cushion plants have formed peat bodies over thousands of years that fill many valley bottoms, and the forage produced by the plants is critical for native and nonnative domesticated mammals. The sources and flow paths of water supporting these peatlands remain largely unknown. Some studies have suggested that glacier meltwater streams support some peatlands, and that the ongoing loss of glaciers and their meltwaters could lead to the loss or diminishment of peatlands. We analysed the hydrologic regime of 10 peatlands in four mountain regions of Bolivia and Peru using groundwater monitoring. Groundwater levels in peatlands were relatively stable and within 20 cm of the ground surface during the rainy season, and many sites had water tables 40–90 cm below the ground surface in the dry season. Topographic and groundwater elevations in the peatlands demonstrated that the water source of all 10 peatlands was hillslope groundwater flowing from lateral moraines, talus, colluvium, or bedrock aquifers into the peatlands. There was little to no input from streams, whether derived from glacier melt or other sources, and glacier melt could not have recharged the hillslope aquifers supporting peatlands. We measured the stable water isotopes in water samples taken during different seasons, distributed throughout the catchments, and the values are consistent with this interpretation. Our findings indicate that peatlands in the study region are recharged by hillslope groundwater discharge rather than stream water and may not be as vulnerable to glacial decline as other studies have indicated. However, both glaciers and peatlands are susceptible to changing thermal and precipitation regimes that could affect the persistence of peatlands.

A pesar de la importancia de los bosques de Polylepis para la biodiversidad y la provisión de servicios ecosistémicos en el Altiplano del extremo sur del Perú (departamento de Tacna), se cuenta con muy poca información científica actualizada que sustente acciones efectivas de conservación. Mediante técnicas de sensoramiento remoto se ha delimitado la superficie de los bosques de Polylepis tarapacana en la cuenca Maure (Altiplano del departamento de Tacna) y evaluado los principales factores ambientales que afectan su desarrollo. Se comparó la superficie obtenida con factores ambientales influyentes para su desarrollo como la altitud, el clima y una serie de índices morfométricos como la orientación y la protección topográfica. A diferencia de otros bosques de Polylepis, la orientación dominante de estos parches de Polylepis tarapacana es N-NE-E, expuesto a insolación durante las horas previas al mediodía, además se desarrolla en sectores de baja protección del relieve y poca probabilidad de intercepción con acuíferos cercanos (valores negativos para el índice de humedad). El 56,66% del área identificada intercepta al polígono de Polylepis del Mapa Nacional de Ecosistemas del Perú del año 2018, el 30,12% se encuentra bajo una modalidad de conservación y el 74,49% se encuentra dentro de terrenos de seis comunidades campesinas. Esta investigación genera un polígono de bosque más preciso que los disponibles en la actualidad, y permite evaluar las alternativas para su protección. La ampliación del Área de Conservación Regional Vilacota - Maure emerge como la mejor opción para asegurar la preservación de este bosque, puesto que asegura la protección de la casi totalidad del área identificada.

Aquatic organisms with different adaptations are used as indicators in physical habitat simulation system models. Those adaptations are critical for determining the shape of the weighted usable area/width curve and for recommending values of environmental flows. The main objective of this study is to compare the use of benthic native species (Astroblepus taczanowskii and Astroblepus vanceae) versus the introduced Oncorhynchus mykiss (rainbow trout) as target indicators for PHABSIM modelling in the Andean–Amazon piedmont rivers. We used adjusted probability distribution functions with L‐moments analyses for developing curves of use and preference to evaluate the efficiency of each indicator. Two hydraulic modelling sections were established in the Ulcumayo River with 21 and 27 cross sections, respectively. Native benthic species are usually dominant but scarcely used as focus organisms for environmental flows modelling. These species are associated with fast running and shallow waters, which makes them potentially more sensitive to the effects of flow reduction. Our results indicated that the native species were more restricted to velocity and depth than O. mykiss. Using selection curves in PHABSIM modelling, it is required between 10% to 94% of the mean monthly flow to preserve 90% of the available habitat for Astroblepus during the dry season (May to November). In contrast, rainbow trout requires 5% to 88% of the mean monthly flow. We conclude that a multispecies approach is useful for determining the required environmental instream flows contributing to a better sustainable condition for the Neotropical mountain rivers.

La inamovilidad ciudadana determinada por la pandemia de COVID-19 generó una serie de impactos sobre el ambiente. Con el objetivo de evaluar la naturaleza de dichos impactos, se aplicó una técnica matricial (RIAM) que luego fue contrastada con información satelital de calidad de aire (CO y NO2), vigor vegetal en agroecosistemas (NDVI) y productividad primaria marina (OC3). Todos los impactos evaluados mediante el análisis matricial fueron calificados como positivos, aunque de corta duración y reversibles. En base a la información satelital, se observó una reducción equivalente al 16 % en la concentración de CO y al 4 % en NO2, mientras que el estado de la vegetación agrícola o la concentración de algas en el litoral no presentaron cambios. Los resultados indicaron que los impactos del confinamiento fueron positivos, pero de corta duración y restringidos a variables asociadas a actividades urbanas e industriales.

As in many other countries, Peru has the Water Quality Standard (WQS) as the primary tool for managing and diagnosing water resources. An analysis of variable by variable was applied to define water quality as poor or good by setting concentration limits. A second group of tools commonly used are Biotic Indexes based on tolerance of benthic macroinvertebrates to pollution, that reflect the impacts caused by a group of variables, even though they cannot identify which variables determine the viability of the ecosystem. This research proposes to include the Stable States approach to evaluate the ecological integrity in central‐Andes rivers to explore an alternative approach with the capacity to represent a broader number of factors through multivariate analyses. A ten‐year database of biological, physical, and chemical variables measured in five Andean Rivers was evaluated. Our results suggest these rivers fluctuate into two seasonal stable states (wet and dry season), accounting for approximately 41% of the system variability. The wet season stable state was defined by high levels of suspended solids and turbidity, coliform, phosphorus, and some metals. During the dry season, the key variables were dissolved solids, barium, pH, and dissolved oxygen. Likewise, there seems to be a third alternative state influenced by human pressures driven by organic pollution variables that exceed the WQS. Regarding water quality, the concentrations of coliforms, phosphorus, and lead usually exceeded the limits in two stations, but not every year. Between bioindicator indexes, the ABI represented the ecological condition more accurately than EPT.