La fragmentación de los ecosistemas naturales viene siendo un grave problema mundial, ocasionado por la construcción de infraestructura convencional, que, si bien ha contribuido al desarrollo económico de las grandes ciudades, su instalación y funcionamiento afecta socioeconómicamente a diferentes poblaciones rurales, creando en ellas condiciones y sensaciones de marginalidad y pobreza. Por ello, se ha evaluado mediante la ecología del paisaje y un software especializado, si aquella construida desde el año 1975 en la puna del Departamento de Tacna, ha provocado efectos ecológicos sobre sus ecosistemas y sociedades altoandinas, determinándose que 267,3 km2 de infraestructura convencional (5.51% de la superficie total) ha provocado el efecto barrera sobre el Suri y el efecto área en diversas especies de flora silvestre, reduciendo su abundancia, diversidad y cobertura, pero también del efecto borde, evidenciado por cambios en la humedad relativa y temperaturas del suelo y ambiente encontradas. La interacción del hombre rural con su entorno natural satisface sus necesidades humanas, comprobándose .- que el reemplazo parcial o total de los ecosistemas, ha limitado las condiciones básicas de desarrollo, como el acceso a recursos y la exclusión 110 en las decisiones sobre ellos, generando un clima de injusticia, provocando reclamos y oposiciones durante los conflictos sociales pasados que aún son latentes, por lo que la implementación de mejores mecanismos de evaluación del impacto ambiental, de gestión territorial, de restauración y desarrollo rural, basado en la conservación de sus ecosistemas y las compensaciones o retribuciones efectivas por servicios ecosistémicos, garantizaran el desarrollo y la paz social en las sociedades altoandinas de la ecorregión Puna.

. In the southernmost Andean regions of Peru, Moquegua, and Tacna, close to Chile and Bolivia borders, large forest stands of Polylepis species are essential for the social, economic, and environmental functionality of six basins. However, the need for more knowledge about their ecology, limited conservation efforts, and insufficient technical capacities for territorial regulation could accelerate their structural and functioning deterioration. Using landscape ecology -interdisciplinary science shaped by geography and biologywe found that in four evaluated areas, the composition of birds (and therefore also the resources they use) is differentiated by the influence of landscape fragmentation. Only two protected areas were legally recognized in the region, but they were established to cover small and remote isolated territories, which makes it challenging to conserve them effectively. Due to the poverty conditions common among the local communities, extractive or pastoralist activities conducted in large areas can trigger higher forest fragmentation rates. Under these circumstances, the valuable ecosystem services in the study area would be permanently lost or maintained at high risk. Because of these risks, specific measures were proposed to improve the social-environmental management of the forest by implementing mechanisms aimed at generating sustainable economic benefits in a healthy environment and social peace.

As in many other countries, Peru has the Water Quality Standard (WQS) asthe primary tool for managing and diagnosing water resources. Ananalysis variable by variable to define water quality as poor or goodwas applied by setting concentration limits. A second group of toolscommonly used are Biotic Indexes based on tolerance of benthicmacroinvertebrates to pollution, that reflect the impacts caused by agroup of variables, even though they cannot identify which variablesdetermine the viability of the ecosystem. This research proposes toinclude the Stable States approach to evaluate the ecological integrityin central Andes rivers to explore an alternative approach with thecapacity to represent a broader number of factors through multivariateanalysis. A ten-year database of biological and physical-chemicalvariables measured in five Andean rivers were evaluated. Our resultssuggest these rivers fluctuate into two seasonal stable states (wet anddry season), accounting for approximately 31% of the systemvariability. In the wet season, the equilibrium of the state wasdominated by the highest levels of suspended solids, turbidity,coliform, phosphorus, and some metals. During the dry season, the keyvariables were dissolved oxygen, flow, physical habitat, and biotic anddiversity indexes. Likewise, there seems to be a third alternative stateinfluenced by human pressures because of variables that exceed the WQS.Regarding water quality, the concentrations of coliforms, phosphorus,and lead usually exceeded the limits in two stations, but not everyyear. The ecological condition was better represented by ABI index thanEPT.

The vegetation, geographic distribution, and pastoralist uses of peatlands in the central Andes have been extensively studied over the past 20 years. However, little information exists to characterize the hydrologic processes that support these groundwater-dependent ecosystems or the hydrologic alterations occurring due to human activities or climate changes. This lack of information significantly limits our understanding of how the central Andean Puna, one of the world's most threatened ecoregions, may be altered by increasing temperature and water extraction for human use. In addition, these peatlands provide critical pasture for native and domestic livestock and carbon storage, but overgrazing is an important modifier of their ecological trajectories. We analyzed three groundwater-fed fen peatlands with differing hydrologic regimes, annual precipitation, land use, and vegetation composition. Water table depth was a key factor significantly contributing to differences in soil hydraulic conductivity (p < 0.05) and vegetation composition (p < 0.05). Saturated hydraulic conductivity (K) varied from 0.57 m day(-1) to 0.03 m day(-1) for the horizontal component (K-h) and 0.07 to 0.002 m day(-1) for the vertical component (K-v). The principal differences in K were in the seasonally unsaturated upper soil layers at 0-75 cm depth. The annual deepening in the water table and Distichia muscoides dominance drive the variability in K for these layers. Those drivers were themselves correlated but can individually modify K, increasing the decomposition rate and porosity (WT deepening) and altering the initial peat structure (D. muscoides dominance). Three vegetation communities were identified, one in sites with the deepest water tables, the lowest hydraulic conductivities, and dominance of Werneria pygmaea and Plantago rigida. The second community, dominated by bunch grasses in the genus Calamagrostis, occurred in areas with the most variable water table and medium hydraulic conductivity. The third community occurred in the most hydrologically stable areas, with the shallowest water table, highest hydraulic conductivities, and was dominated by Distichia muscoides. The study peatlands appear to have originated as the third community - groundwater-supported fens dominated by Distichia muscoides cushion and pool communities. However, modern hydrologic changes caused by human land uses and climate variability have caused a divergence in the vegetation, and in the more disturbed sites created higher decomposition rates in the shallow peat layers, and differences in soil structure.

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.

Despite the importance of Polylepis forests for biodiversity and the environmental services provision in the southern Peruvian Altiplano (Tacna department), there is no updated scientific information to support effective conservation activities. Through remote sensing techniques the surface of Polylepis tarapacana forests in the Maure basin has been mapped and the main environmental factors were evaluated. The forest area obtained was compared with environmental factors such as altitude, climate, orientation and topographic protection. Unlike other Polylepis forests, the dominant orientation of Polylepis tarapacana patches is N-NE-E, exposed to solar insolation before the noon, and developing in areas with low morphometric protection and negative topographical wetness index (low probabilities to meet with shallow groundwater tables). 56,66% of the area obtained intercepts the Polylepis polygon of the 2018 National Map of Ecosystems of Peru, 30,12% is under regional conservation modality and 74,49% is located within the territories of six rural communities. This research generates a more precise forest polygon than those currently available, and allows the evaluation of alternatives for its protection. The expansion of the Regional Conservation Area Vilacota - Maure emerges as the best option to ensure the preservation of this forest, since it ensures the protection of almost all of the identified area.

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.

La lagunaAricota se ha mantenido ''biológicamente'' estable en los últimos años, a pesar de la extracción de agua por parte de las centrales hidroeléctricas (Aricota I y II) y la disminución del cauce por parte de sus afluentes (ríos Callazas y Salado). El objetivo del trabajo tuvo como propósito la identificación de las diferentes comunidades acuáticas (fitoplancton, perifiton, zooplancton, macroinvertebrados bentónicos y peces). El estudio se realizó durante cinco meses en 5 estaciones de muestreo, a fines de 2017 e inicios del 2018, a lo largo de la zona litoral y pelágica de la laguna. En los resultados, el fitoplancton estuvo representado por 52 morfoespecies distribuidas en: 6 Phyllum, 26 ordenes y 31 familias; el perifiton, con 56 morfoespecies distribuidas en: 8 Phyllum, 25 ordenes y 34 familias; el zooplancton, con 13 morfoespecies distribuidas en: 6 Phyllum, 8 ordenes y 11 familias; los macroinvertebrados estuvieron representados por 24 especies distribuidas en: 5 Phyllum, 9 ordenes y 16 familias; y la ictiofauna estuvo representada por Oncorhynchus mykiss y Trichomycterus sp. Los parámetros físico químicos presentaron valores promedio: la temperatura en la zona litoral de la laguna Aricota (HBO1, HBO2, HBO3 y HBO4) fue de 18.0-18.2 °C, mientras que en la zona pelágica (HBO5) fue de 17.9-18.2 °C; en el caso del oxígeno disuelto, la variación en la zona litoral fue de 7.14-7.24 mg/L y en la zona pelágica fue de 7.21-7.24 mg/L; para la conductividad eléctrica, la variación en la zona litoral fue de 1960-2031 µS/cm y en la zona pelágica fue de 1964-2030 µS/cm; y para el pH, la variación en la zona litoral fue de 7.99-8.85 y en la zona pelágica fue de 8.53-9.02. Se concluye que las comunidades acuáticas presentaron una moderada riqueza de especies durante el tiempo de evaluación.

Los bofedales altoandinos son los ecosistemas acuáticos más vulnerables y frágiles, por ser el sumidero de muchas sustancias como sedimentos, minerales, nutrientes de plantas acuáticas y materiales orgánicos. Por ese motivo, el objetivo de la investigación fue determinar la condición trófica y calidad del agua de los bofedales de Candarave mediante el uso de indicadores fitoplanctónicos. Se registró la composición del fitoplancton de dos bofedales de la provincia de Candarave. La colecta de las muestras se realizó con una red de 20 pm y fueron analizados en el laboratorio de botánica de la UNJBG, mediante claves especializadas. Además, se determinó la relación de los parámetros fisicoquímicos del agua con las comunidades del fitoplancton mediante el índice de correlación de Pearson con una significancia de P < 0,05 para establecer relaciones de sensibilidad entre ambas métricas. Los componentes fitoplanctónicos identificados corresponden a 6 divisiones: Cyanobacteria, Euglenophyta, Cryptophyta, Crysophyta, Bacillariophyta y Chlorophyta. Se utilizó a las Bacillariophytas (diatomeas) para la caracterización trófica y calidad del agua. La estimación del índice IDG permite concluir que los bofedales de Candarave (C1 y C2) presentan diferentes condiciones tróficas y calidad del agua en diferentes meses calificados como: polución moderada (eutrofización); polución media (eutrofización acentuada), calidad normal, polución fuerte y condición óptima del agua.

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.

El análisis taxonómico de las diatomeas se utiliza como bioindicador de la calidad del agua. El presente estudio se realizó en el río Tingo al noroeste de Hualgayoc, en los alrededores de la unidad minera Cerro Corona en Cajamarca. Se colectaron muestras en tres estaciones de muestreo E -1, E-2 y E-3, ubicadas en la cuenca, tanto en la temporada seca (mayo) como húmeda (diciembre) de 2017. En estas estaciones se registraron varios parámetros físico-químicos: OD (ppm), pH, temperatura, conductividad eléctrica y los sólidos totales disueltos (ppm). Se encontró una dominancia de las diatomeas (Bacillariophyta) del 83%. El resto de fitoplancton estaba representado por otros grupos taxonómicos, como las cianobacterias 9%, chlorophyta 6%, mientras que las euglenophyta y xanthophyta representaron solo el 1 %. Según la métrica del índice Diatónico Genérico (IDG), las estaciones E-2 y E-3 se evaluaron con calidad de agua pésima, y E-l con calidad de agua mala. Se observaron formas teratológicas en tres especies de diatomeas Ulmaria una (270 células/ml), Fragilaria spp (180 células/ml) y Synedra goulardii (129 células/ml). Las formas teratológicas aparecen como un efecto accidental de las tensiones ambientales, tanto físicas como químicas; tipos de estrés; contaminación orgánica, metales pesados.

Peatlands (known as _bofedales_ in the Peruvian Andes) provide important social and environmental services in the Peruvian Puna ecoregion, especially as sources of water and forage for domestic livestock. In biological terms, these peatlands are key habitats with their own community structure, dynamics and interactions; and they serve as biodiversity hotspots within the High Andes. In this article we assess the relationships between: (i) physical structure, (ii) water quality, (iii) plant communities and (iv) the assemblages of aquatic invertebrates (benthic macroinvertebrates) in three peatlands located in Cuzco Region, southern Peru. The results suggest that the benthic macroinvertebrate assemblage is a good indicator of the trophic status of the small pools that are typically present in bofedales. Trophic status is, in turn, primarily related to spatial and seasonal water availability and the types of plant communities present in each peatland.

Trichomycterus punctulatus is an endemic benthopelagic freshwater catfish found in the western systems of Peru; it is a predator and as such is a good integrator of ecological information. The information generated from this species will improve a better understanding of community structure and promote its conservation and management. Feeding habits of T. punctulatus were determined by analyzing the stomach contents of 127 individuals collected in two seasons: dry (August, 2010) and wet (May, 2011), in three sectors (6 sampling stations) of the Pisco river middle basin. Feeding items were set at the family level, and the Index of Relative Importance (IRI) and the Index of Numerical Importance (INI) were calculated. It was found out that T. punctulatus mainly consumes individuals from the Chironomidae, Hydropsychidae and Leptohyphidae families during the dry season; whereas in the wet season, it consumes individuals from the Chironomidae and Elmidae families. Using the linear food selection index (L), it was determined that T. punctulatus is not an active selector, being rather opportunistic. The graphical method of Cortes (1997), determined that the feeding strategy of T. punctulatus is a generalist. Finally with a Kruskal-Wallis analysis, it was determined that there are changes in feeding habits within basin sectors and among dry and wet seasons.

Abstract Biological monitoring programs provide data and information for decision making and to ensure the resources protection. However, in tropical ecosystems that are home to most of the planet's biodiversity these programs need to be improved in design and implementation. As part of the Environmental Management Plan "Environmental Impact Assessment for the 2D-3D Seismic Program and drilling of 22 exploratory wells in Kinteroni, Mapi and Mashira – Block 57" (Peru), we develop a Biological Monitoring Plan to keep track of potential biological changes (temporal and spatial scale) caused by the project activities to identify the need for corrective actions or to define new measures for unforeseen impacts. Temporarily, the activities of the monitoring plan depend on the stages of the project (construction, operation and closure), meanwhile they correspond spatially to factors that may cause effects on the flora and fauna. Block 57 is located in the Amazon rain forest of southern Peru; this is an ecosystem with limited information. Seeking a scheme to support exploration activities, It has been designed a systematic biological monitoring program, based on a gradient of disturbance caused by the clarification of an area. This design is intended to identify the variables that are most sensitive to the effect of exploration activities in forests with similar features and comparable seasons. The design is being implemented in exploratory platforms of Block 57 located in the buffer zones of the Ashaninka and Machiguenga Communal Reserves and Otishi National Park, covering the three stages of the drilling process, and evaluating spatially flora and arthropods to smaller scale (≤ 150 m from the edge of the deforested area) and birds, small mammals and reptiles at the mesoscale (≤ 600 m from the edge of the deforested area), in the area around the cleared area. The information generated, besides determining the parameters used to assess the level of impacts on local wildlife generated during the drilling, helps to evaluate the effectiveness of appropriate sampling methodologies and optimizes logistics; looking forward to replicate this design in other tropical ecosystems.

Trichomycterus punctulatus es un bagre de agua dulce de hábitos bentopelágicos, endémico de los ríos de la vertiente occidental del territorio peruano. Se trata de un depredador situado en la cima de la cadena trófica y como tal, podría constituir un buen integrador de la información ecológica, por lo que generar información sobre esta especie contribuiría con un mejor entendimiento del ensamblaje comunitario, además de propiciar su conservación y manejo. Los hábitos alimentarios de T. punctulatus se determinaron analizando el contenido estomacal de 127 individuos colectados durante dos estaciones del año: seca (Agosto, 2010) y húmeda (Mayo, 2011), en 3 sectores (6 estaciones de muestreo) de la cuenca media del río Pisco. Los ítems alimenticios, fueron identificados a nivel de familia. En base a estos datos se calcularon el Índice de Importancia Relativa (IRI) y el Índice de Importancia Numérica (INI), encontrándose que T. punctulatus consume principalmente individuos de las familias Chironomidae, Hydropsychidae y Leptohyphidae durante la temporada seca; mientras que en la temporada húmeda, consume individuos de las familias Chironomidae y Elmidae. Mediante el índice lineal de selección de alimentos (L), se determinó que T. punctulatus no presenta una selección activa, siendo más bien oportunista. Con el desarrollo del método gráfico de Cortés (1997), se determinó que la estrategia alimentaria de T. punctulatus es generalista. Por último con un análisis de Kruskal-Wallis se determinó que existe variación en los hábitos alimentarios por sector de cuenca y, entre las temporadas seca y húmeda.

Salmonidae were introduced in the Peruvian freshwaters during the first quarter of the 20th century with the Rainbow Trout, Oncorhynchus mykiss (Walbaum, 1792), and later with three more species: Salmo trutta Linnaeus, 1758, Salvelinus namaycush (Walbaum, 1792) and Salvelinus fontinalis (Mitchill, 1814). Only Oncorrynchus mikyss seems to have established itself extensively and successfully, is regularly reported and appears on the taxonomic checklists. This article reports on the presence of Salvelinus fontinalis in the high Andes of southern Peru, an area which is biogeographically associated with the Lake Titicaca Plateau.

This paper discusses the appropriate number of Sample Units and the Minimum Sample Size (MSS) to determine the least biased value for estimating the density of benthic macroinvertebrates. This analysis applies to sections with similar physiographic and ecosystem characteristics in lotic habitats of mountainous rainforest. The data analyzed were obtained from intensive sampling using the Surber net method in an Andean-Amazonic piedmont river in central Peru (Colorado River, Chanchamayo river basin, Chanchamayo province in Junin). The results indicate that collecting efforts less than 12 Sample Units and individual samples equal or less than five replicates provide low quality data for density estimation. The results here obtained were compared with some empirical density estimations cited in Peruvian journals and technical reports since year 2000.

En este documento se discute sobre el número apropiado de Unidades Muestrales y el Tamaño Mínimo de Unidad Muestral (TUM) recomendable, para la estimación más precisa posible de un valor referencial de la densidad de macroinvertebrados bentónicos. El enfoque del análisis está referido a secciones con parámetros homogéneos en cuanto a fisiografía y características generales de hábitat, en ambientes lóticos en selva de montaña. Se analizaron datos provenientes de un muestreo intensivo mediante el uso de red Surber en un rio de piedemonte Andino-Amazónico en el Perú central (Río Colorado, cuenca del Río Chanchamayo, Provincia de Chanchamayo, Región Junín). Los resultados indican que muestreos con esfuerzos por debajo de las 12 unidades muestrales y muestras individuales constituidas por cinco o menos réplicas, aportan datos muy poco confiables para estimar la densidad. Sobre la base de los resultados obtenidos se realizaron comparaciones con algunas aproximaciones empíricas en la estimación de densidad citadas en artículos científicos y reportes técnicos publicados en el Perú desde el año 2000.