Carlos A. Rivera-Rondón

Unidad de Ecología y Sistemática, Departamento de Biología, Pontificia Universidad Javeriana, Bogotá, Colombia []

Developing a diatom calibration dataset for environmental reconstruction in Colombian high-mountain lakes

The ecological response of diatom to water chemistry of lakes is the basis for reconstructing past environmental conditions using lake sedimentary records. Diatom training-sets have been extensively implemented in high-mountain lakes at high latitudes. The environmental reconstruction using diatoms has been focused on their strong ecological response to pH and alkalinity. However, the ecology of diatoms can be used also in the reconstruction of other environmental variables. Thus, the study of diatom ecology in oligotrophic environments, such as the mountain lakes in the Pyrenees, has shown diatom versatility to reconstruct different chemical variables and habitat characteristics of lakes using a single diatom calibration data set. The use of diatom in environmental reconstruction is subordinated to the knowledge of their taxonomy and ecology in a regional context. In equatorial ecosystems, major order factors such as climate and geology are affecting lakes in a different way with respect to temperate ones. Despite there are few studies in Colombian high-mountain lakes, it is expected a different ecological diatom response to environment. The presence of a large vegetation cover in the basin and a constant temperature through the year substantially affects water chemistry and increase the diversity of potential habitats where diatoms can grow. Therefore, the ecological relationships between diatoms, chemistry and habitats have to be recognized prior to their use in environmental reconstruction. Accordingly, this project is oriented towards the generation of basic taxonomical and ecological information of diatoms in Colombia Páramo lakes. In this presentation, I use the experience developing and using diatom-based transfer function in Pyrenes lakes to develop a conceptual framework for studying Colombian high-mountain lakes.