ABSTRACT The inland waters in the Andes Mountains in the extreme north of Chile are in a zone with a marked arid climate in the called Atacama Desert (23° S, Antofagasta region, Chile) that has sporadic rains mainly in January or February (summer rains/Altiplano winter), many of these water bodies have high mineral contents due high mineral contents, and low species diversity (mainly crustacea and insecta). The present study aims to do a comparative analysis of inland water crustaceans in different kinds of water bodies in the surroundings of San Pedro de Atacama and Salar de Atacama in the north of Chile using co-occurrence null model analysis. The results revealed a scarce species richness and random species associations due to the lack of a structured pattern and many recurring species in the studied sites. Species reported, and species associations agree with literature descriptions. Nevertheless, more ecological studies would be necessary to understand the community patterns in these water bodies.

RESUMEN Los cuerpos de agua en la cordillera de los Andes del extremo norte de Chile están en una zona con un clima árido marcado en el denominado Desierto de Atacama (23° S, Región de Antofagasta, Chile), que tiene lluvias esporádicas en enero o febrero (lluvias estivales/invierno altiplánico), muchos de estos cuerpos de agua tienen alto contenido de minerales y baja riqueza de especies (principalmente crustáceos e insectos). El objetivo del presente estudio es realizar un análisis comparativo de los crustáceos de aguas continentales en diferentes tipos de cuerpos de agua en los alrededores de San Pedro de Atacama y del Salar de Atacama en el norte de Chile usando análisis de modelos nulos de co-ocurrencia de especies. Los resultados revelaron que hay baja riqueza de especies y que las asociaciones de estas son aleatorias, debido a la carencia de un patrón estructurado, por la presencia de muchas especies repetidas en los sitios estudiados. Las especies reportadas y las asociaciones de especies reportadas concuerdan con los antecedentes de la literatura. No obstante, serían necesario más estudios ecológicos para comprender los patrones comunitarios en estos cuerpos de agua.

Abstract Temporary pools are freshwater bodies of significant interest due to their high species diversity, and the colonization and extinction processes observed at temporal scales. The aim of the present study was to perform a short-term ecological comparison in a group of shallow temporary pools in northern Chilean Patagonia in two periods, August and September 2018. The results revealed marked differences in terms of species richness in the study pools at different conductivities and chlorophyll a concentrations. The dominant species was the calanoid copepod Boeckella gracilis Daday, 1902, while the presence of the rare Anostracan Branchinecta rocaensis Cohen, 1982 was reported in conditions of low chlorophyll a and low conductivity. The community was studied using co-occurrence null models that revealed the absence of structured patterns in species associations, and the presence of niche overlap, with many repeated species that have a similar ecological niche. The present results are identical with observations from temporary pools in southern Chilean Patagonia.

RESUMO A fauna bentônica nos córregos do norte da Patagônia é caracterizada pela presença de espécies indicadoras de qualidade da água. O objetivo do presente estudo foi caracterizar as comunidades bentônicas em riachos associados a locais com presença de florestas de Nothofagus e com intervenção humana sem florestas de Nothofagus usando modelos nulos em ecologia, teoria unificada de biodiversidade unificada (UNTB) e método de grupo de par não ponderado com média aritmética (UPGMA). Os resultados do modelo nulo de co-ocorrência de espécies revelaram que as associações de espécies são aleatórias, enquanto os resultados de modelos nulos de sobreposição de nicho revelaram a presença de sobreposição de nicho. Os resultados do UNTB revelaram baixo número de espécies. Os resultados da UPGMA demonstraram que a composição de espécies é específica para cada local, existindo diferenças marcadas. Os resultados expostos concordam com os resultados observados para os rios chileno central e norte da Patagônia, onde a composição das espécies é variável de acordo com as propriedades da bacia circundante e às condições sazonais.

ABSTRACT The benthic fauna in northern Patagonian streams is characterized by presence of water quality indicator species. The aim of the present study was characterized the benthic communities in streams associated to sites with presence of Nothofagus forests and with human intervention without Nothofagus forests using null models in ecology, unified neutral theory of biodiversity (UNTB) and unweighted pair group method with arithmetic mean (UPGMA). The results of species co-occurrence null model revealed that species associations are random, whereas the results of niche overlap null models revealed the presence of niche overlap. The UNTB results revealed low species number. The results of UPGMA revealed that species composition is specific for each site existing marked differences. The exposed results agree with results observed for central and northern Patagonian Chilean rivers, where the species composition is variable in according to surrounding basin properties and seasonal conditions.

ABSTRACT Genypterus chilensis is a marine fish of high gastronomic demand, whose capture has declined in recent years due to overfishing. In the development of the farming technology, high mortalities were obtained during egg incubation. The objective of this study is to contribute to the knowledge of fecundity and eggs viability of G. chilensis in captivity. The spawns of G. chilensis were analyzed over a period of 2 years and 3 months. The total fecundity was estimated by counting the masses and eggs produced monthly throughout the period. The results confirm that G. chilensis is a partial spawner, since a female may more than two masses of eggs per day, due to a large amount of mass spawned per season (621 average). The total production of masses of the Farming Centre during the period was 2,290; of these, only 7% (166) corresponding to 15,330,517 eggs were incubated. Because of its high fecundity, G. chilensis produces numerous masses of eggs, of which only a small percentage reaches incubation, as well as it occurs in other marine fish.

ABSTRACT Decomposition of leaf litter is a fundamental process for the functioning of forested wetlands. The rapid increment of forest plantations has involved a greater contribution of leaf litter of exotic origin to these ecosystems. The decomposition rate between leaf litter of native and exotic origin in a forested wetland of the Mediterranean zone of Chile was compared, as well as the contribution of bacteria and macroinvertebrate to this process. It was determined that the decomposition rate of the leaf litter presented significant differences (p < 0.05) between species, being faster in those of non-native origin. This could be due to differences in ecophysiological aspects of the leaves like the presence of chemical compounds such as waxes or oils. Both analyzed communities were relevant in the studied process. However, bacteria contributed mostly to the decomposition of both types of leaves. The implications of the physical and chemical characteristics of the leaves and the water on the processing of the foliar material are discussed.

RESUMEN En los humedales boscosos, la descomposición de la hojarasca es un proceso fundamental para su funcionamiento. El rápido incremento de las plantaciones forestales ha implicado un mayor aporte de hojarasca de origen exótico a estos ecosistemas. Se comparó la tasa de descomposición entre hojarasca de origen nativo y exótico en un humedal boscoso de la zona Mediterránea de Chile, así como la contribución de las bacterias y macroinvertebrados a este proceso. Se determinó que la tasa de descomposición de la hojarasca presentó diferencias significativas entre las diferentes especies (p < 0,05), siendo más rápido en especies de origen exótico. Esto podría ser dado por diferencias en algunos aspectos ecofisiológicos de las hojas como la presencia de compuestos químicos tales como ceras o aceites. Ambas comunidades analizadas fueron relevantes en el proceso estudiado. Sin embargo, las bacterias contribuyeron mayormente a la descomposición de ambos tipos de hojas. Se discuten las implicaciones de las características físicas y químicas de las hojas y el agua en el procesamiento del material foliar.

Ecosystem services provide many benefits to society. These services have been classified into four categories: provisioning services, regulating, cultural and support. One of the major gaps in mapping these services is related to the lack of a standardized methodology that integrates biophysical and perceptual variables derived from the vision of relevant actors in a territory. Multi-criteria spatial analysis (MCSA) is an appropriate methodological framework to integrate this type of information. The present study aims at proposing and applying a methodology of multi-criteria analyses based on GIS tools and homogeneous environmental units (HEU) for mapping ecosystem services in Quepe river basin. Results indicated that provision, regulation and cultural services were significantly associated with the HEU Bosque Nativo. Furthermore, the level of presence of these services was significantly lower in the HEU Plantación and Tierras Agrícolas. We conclude that the method has the advantage of providing ease and flexibility in data spatialization, while collecting perceptual values of a specific service in the sub-basin.

Los servicios ecosistémicos proveen variados beneficios a la sociedad. Dichos servicios han sido clasificados en cuatro categorías: servicios de provisión, regulación, soporte y culturales. Una de las principales brechas en el mapeo social y la espacialización de estos servicios, se relaciona con la ausencia de una metodología que integre variables biofísicas y perceptuales de actores relevantes en un territorio. El análisis espacial multicriterio (AEMC) constituye un marco metodológico apropiado que permite integrar esta información. La presente investigación tuvo como objetivo proponer y aplicar una metodología de análisis multicriterio, basado en herramientas SIG y unidades ambientales homogéneas (UAH) para el mapeo de servicios ecosistémicos en la subcuenca del río Quepe. Los resultados indicaron que los servicios de provisión, regulación y culturales, estuvieron significativamente presentes y asociados a la UAH bosque nativo. Por otro lado, el nivel de presencia de estos servicios fue significativamente menor en las UAH plantaciones y terrenos agrícolas. Se concluye que el método presenta la ventaja de otorgar facilidad y flexibilidad en la espacialización de datos, mientras que recoge de manera sencilla los valores perceptuales de los actores locales y cómo estos perciben el nivel de presencia de un determinado servicio en la subcuenca.

C. Esse, PJ. Donoso, V. Gerding, and F. Encina-Montoya. 2013. Determination of homogeneous edaphoclimatic zones for the secondary forests of Nothofagus dombeyi in central-southern Chile. Cien. Inv. Agr. 40(2): 351-360. Nothofagus dombeyi grows in a wide variety of sites in Chile (30-47°S), but there is little knowledge about its productive potential. This lack of information hinders decision-making to better guide the production of goods and services from these forests. This study was conducted in central-southern Chile (39°S-41°S), where this species is prominent, especially in secondary forests. The aim of the study was to determine the homogeneous edaphoclimatic zones for secondary forests of N. dombeyi based on the integration of environmental factors. The methodological approaches considered the spatial analysis and construction of geographic covers using geographic information systems, principal components multivariate analysis, and clustering techniques with CART analysis. Five homogeneous zones could be determined for N. dombeyi with a high level of accuracy. The spatial distribution of N. dombeyi secondary forests was explained in decreasing order by climate, soil and topography.

C. Esse, PJ. Donoso, V. Gerding y F. Encina-Montoya. 2013. Determinación de zonas edafoclimáticas homogéneas para bosques secundarios de Nothofagus dombeyi en el centro-sur de Chile. Cien. Inv. Agr. 40(2): 351-360. Nothofagus dombeyi crece en una amplia variedad de sitios en Chile (30-47 ° S), por ello existe escaso conocimiento sobre su potencial productivo. Esto dificulta la toma de decisiones que orienten de mejor forma la producción de bienes y servicios de estos bosques. Este estudio se llevó a cabo en el centro-sur de Chile (39° S-41° S), donde esta especie es prominente, especialmente en bosques secundarios. El estudio tuvo como objetivo determinar zonas edafoclimáticas homogéneas para los bosques secundarios de N. dombeyi, basado en la integración de factores biofísicos. Los enfoques metodológicos consideraron análisis espacial y construcción de coberturas geográficas por medio de sistemas de información geográfica, análisis multivariado de componentes principales y técnicas de agrupamiento con análisis CART. Fue posible determinar cinco zonas homogéneas para N. dombeyi con un alto nivel de precisión. La distribución espacial de la especie se explicó en orden decreciente por los factores biofísicos clima, suelo y topografía.

Based on recent advances in ecological network theory, we present an ad hoc conceptual framework and a methodological proposal for the evaluation of the ecological relevance of species within a community, oriented towards the Ecological Risk Assessment in Chilean aquatic systems. The procedure is theoretical and based on the quality of available information, i.e. it does not require experimental tests or field observation. Given the current and medium-term expected state of knowledge about the structure of local aquatic communities, the proposed method is focused towards its application to communities whose level of knowledge is low or medium. The proposal uses qualitative criteria and quantitative indices (seven topological indices and one index based on qualitative modeling) for the identification of ecologically relevant species that represent at least three trophic categories within the community.

En base a avances recientes en teoría de redes ecológicas, se presenta un marco conceptual ad hoc y una propuesta metodológica para la evaluación de la relevancia ecológica de las especies de una comunidad, orientada a la Evaluación de Riesgo Ecológico de sistemas acuáticos en Chile. El procedimiento es de carácter teórico y se basa en la calidad de la información disponible, es decir no requiere de evaluaciones experimentales ni observacionales de campo. Dado el estado de conocimiento actual y esperado a mediano plazo acerca de la estructura de las comunidades acuáticas locales, el método propuesto está enfocado a su aplicación en comunidades cuyo nivel de conocimiento es bajo o medio. La propuesta utiliza criterios cualitativos e índices cuantitativos (siete índices topológicos y un índice basado en modelación cualitativa) para la identificación de especies ecológicamente relevantes que representen al menos tres categorías tróficas de la comunidad.

Los macroinvertebrados han sido utilizados por décadas para evaluar la calidad de las aguas, utilizando medidas de diversidad, índices bióticos y comparativos, sugiriendo que el nivel taxonómico de familia permite una buena interpretación general de la calidad ecológica de un sistema fluvial y es posible hacer inferencias sobre la calidad de éstos sistemas respecto a condiciones de referencias seleccionadas. Este trabajo analiza independientemente tres localidades de Chile centro-sur, mediante un análisis de agrupación, evaluando si existe pérdida de información al utilizar dos niveles jerárquicos, destacando que el nivel de familias en macroinvertebrados bentónicos es suficiente para la realización de monitoreos ambientales. Se discuten las ventajas prácticas, la capacidad integradora que puede alcanzarse y su relación con las variables ambientales.

Macroinvertebrates have been used for decades to evaluate water quality, using measures of diversity, biotic indexes and comparative analysis. The taxonomic level of family allows a general interpretation of the ecological quality of a fluvial system, and is possible to infer the quality of these systems compared to selected references sites. This paper analyzed three localities of Central-South Chile by means of grouping analysis, evaluating if there is any loss of information when using two hierarchic levels. It is shown that the family level of benthic macroinvertebrates is sufficient for environmental monitoring. The practical advantages, the integrating capacity that can be reached and its relation with environmental variables are discussed.

Os macroinvertebrados têm sido utilizados por décadas para avaliar a qualidade das águas, utilizando medidas de diversidade, índices bióticos e comparativos, sugerindo que o nível taxonômico de familia permite uma boa interpretação geral da qualidade ecológica de um sistema fluvial e é possível fazer inferências sobre a qualidade destes sistemas com respeito às condições de referências selecionadas. Este trabalho analisa independentemente três localidades do Chile centro-sul, mediante uma análise de agrupação, avaliando se existe perda de informação ao utilizar dois níveis yerárquicos, destacando que o nível de famílias em macroinvertebrados bentônicos é suficiente para a realização de monitoramentos ambientais. Discutem-se as vantagens práticas, a capacidade integradora que pode se alcançar e sua relação com as variáveis ambientais