The lake district concept in the ecological understanding of high mountains

Sets of lakes in the landscape are known as lake districts. The objective of this project is to demonstrate that the lake district acts as a regional functional ecological unit. The hypothesis is that ecological properties, beyond the simple addition of smaller units (lakes), emerge from the densification of lakes in a region. They could result among others from topographical restrictions, border effects, directional environmental gradients, stochastic colonizing patterns, concatenation of dominant biogeochemical processes.

This study is conducted in the lake district of the Pyrenees, for which the research group has a large amount of information after 30 years of limnological and environmental research. The relief of high mountains transforms the dynamics between "islands" (lakes ) in a plane , in a three-dimensional "landscape" or network of "islands". In this situation, some emergent properties may exhibit traits more pronounced, or simply different, due to more explicit connections and physical barriers. The study is divided into four analytical objectives that consider the lake district , respectively , as: i) a network of lakes with varying connection distances between nodes according to the process considered, ii ) a biogeochemical reactor spatially complex, in which how biogeochemical compartments are spatially distributed affects the final result ; iii) a metacommunity in which the influence of spatial and environmental factors may vary according to the lifestyle of the organisms considered iv ) and finally, an ontogenetic unit, where the whole district has a directional historical development, as each of the lakes, interrupted only by major climatic fluctuations or tectonic events. Each of these four aspects will address with some specific studies as possibilities are infinite. For example, the spatial analysis of the distribution of lakes, their size and climatic conditions; the relationship of the soil cover features with the chemical characteristics of the lakes and the organic matter stored in sediments; the assessment of the degree of coupling between N cycle processes at different scales; the spatial and environmental distribution of zooplankton communities as a case for few species per lake; the effects of spatial scales in the distribution of diatom species richness as a case of many species per lake; the analysis of topographic restrictions on the distribution macroinvertebrate richness, as a case of high diversity in dispersal forms; the analysis of changes in diatoms and chrysophyceae stomatocysts diversity (alpha and beta) throughout the Late Glacial and Holocene, the analysis of genetic markers for crustaceans indicative of colonization dynamics, dispersal and local adaptation; among others topics. The final task is to summarise, from all these studies , the general features of the lake district ecological concept as a functional unit and the particular implications for mountain areas and the understanding of current accelerated environmental changes.

Duration: 2014-2016

 Funding Agency: Ministerio de Economía, Industria y Competitividad

 LOOP participants: Jordi Catalan, Marisol Felip, Sergi Pla, Lluís Camarero.

 Coordinator: J. Catalan (CREAF)

Participant institutions: CREAF, CEAB-CSIC