Aquatic community response to volcanic eruptions on the Ecuadorian Andean flank: evidence from the palaeoecological record

Aquatic ecosystems in the tropical Andes are under increasing pressure from human modification of the landscape (deforestation and dams) and climatic change (increase of extreme events and 1.5 °C on average temperatures are projected for AD 2100). However, the resilience of these ecosystems to perturbations is poorly understood. Here we use a multi-proxy palaeoecological approach to assess the response of aquatic ecosystems to a major mechanism for natural disturbance, volcanic ash deposition. Specifically, we present data from two Neotropical lakes located on the eastern Andean flank of Ecuador. Laguna Pindo (1°27.132′S–78°04.847′W) is a tectonically formed closed basin surrounded by a dense mid-elevation forest, whereas Laguna Baños (0°19.328′S–78°09.175′W) is a glacially formed lake with an inflow and outflow in high Andean Páramo grasslands. In each lake we examined the dynamics of chironomids and other aquatic and semi-aquatic organisms to explore the effect of thick (> 5 cm) volcanic deposits on the aquatic communities in these two systems with different catchment features. In both lakes past volcanic ash deposition was evident from four large tephras dated to c.850 cal year BP (Pindo), and 4600, 3600 and 1500 cal year BP (Baños). Examination of the chironomid and aquatic assemblages before and after the ash depositions revealed no shift in composition at Pindo, but a major change at Baños occurred after the last event around 1500 cal year BP. Chironomids at Baños changed from an assemblage dominated by Pseudochironomus and Polypedilum nubifer-type to Cricotopus/Paratrichocladius type-II, and such a dominance lasted for approximately 380 years. We suggest that, despite potential changes in the water chemistry, the major effect on the chironomid community resulted from the thickness of the tephra being deposited, which acted to shallow the water body beyond a depth threshold. Changes in the aquatic flora and fauna at the base of the trophic chain can promote cascade effects that may deteriorate the ecosystem, especially when already influenced by human activities, such as deforestation and dams, which is frequent in the high Andes

Activation During Observed Parent–Child Interactions with Anxious Youths: A Pilot Study

Parent–child interaction paradigms are often used to observe dysfunctional family processes; however, the influence of such tasks on a participant’s level of activation remain unclear. The aim of this pilot project is to explore the stimulus value of interaction paradigms that have been commonly used in child anxiety research. Twenty-nine parent–child dyads with clinically anxious (n = 16) and non-anxious (n = 13) youths engaged in a series of tasks (threat and non-threat) used in previous studies of parenting and youth anxiety. Heart rate (HR) data, as an indicator of physiological activation, were collected across tasks, and participants rated the perceived representativeness of their interactions in the laboratory to their usual behavior at home. Significant HR changes were observed for both parent and child. Change in child HR from baseline to non-threat task was smaller than change in HR from baseline to threat tasks. Change in parent HR from baseline to ambiguous situations tasks was smaller than changes from baseline to other threat tasks. Differences in HR change between anxious and non-anxious children were explored. Participants rated laboratory interactions as similar to those experienced in the home. Results suggest that presumably emotionally-charged discussion tasks may produce increased activation compared to tasks that were designed to be more neutral. Implications for future research and limitations are discussed

Conflict, convergent evolution, and the relative importance of immature and adult characters in endopterygote phylogenetics

10.1146/annurev.ento.54.110807.090459Annual Review of Entomology5485-104AREN

Ethnoecology in pluricultural contexts: Theoretical and methodological contributions

This chapter is a contribution to current ethnoecology from a complex perspective, through a revision of the presuppositions that constitute its theoretical–methodological framework. The systemic approach of ecology understood as a science of synthesis based on relationships between the organism and its environment is discussed. The complex thinking applied to biocultural ecology, based on the relationships between the people and their environment is also discussed, including a reflection about the dissociation between nature and culture, and its conceptual implications. Ethnoecology as the study of local people knowledge system about their own relationships with their environment poses a discussion on sciences and ethnosciences, and its relationships with ecology and biocultural ecology. The reflection about the relationships between the observer and the observed people implies a discussion upon the researcher’s presence in his own research, and how he manages his thinking categories. The role of interviews as communication systems in which the generated knowledge is embodied in actions (discourses and behaviors) is revalued. Ultimately, three cases for the Rio de la Plata riverside (Buenos Aires province, Argentina) are presented. These cases illustrate how the local people identify and value the environmental changes in the pluricultural contexts of the urban areas, and how the obtained results have meaning in the theoretical–methodological framework developed. In conclusion, complex thinking allows us to construct adequate explanations for complex phenomena that ethnoecology tries to explain, and to avoid reductionisms.Fil: Hurrell, Julio Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Stampella, Pablo César. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Doumecq, María Belén. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Pochettino, María Lelia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin