Factors of surface thermal variation in highmountain lakes of the Pyrenees

Este artículo contiene 19 páginas, 6 figuras, 1 tabla.
Thermal variables are crucial drivers of biological processes in lakes and ponds. In the current context of climate change, determining which factors better constrain their variation within lake districts become of paramount importance for understanding species distribution and their conservation. In this study, we describe the regional and short-term interannual variability in surface water temperature of high mountain lakes and ponds of the Pyrenees. And, we use mixed regression models to identify key environmental factors and to infer mean and maximum summer temperature, accumulated degree-days, diel temperature ranges and three-days’ oscillation. The study is based on 59 lake-temperature series measured from 2001 to 2014. We found that altitude was the primary explicative factor for accumulated degree-days and mean and maximum temperature. In contrast, lake area showed the most relevant effect on the diel temperature range and temperature oscillations, although diel temperature range was also found to decline with altitude. Furthermore, the morphology of the catchment significantly affected accumulated degree-days and maximum and mean water temperatures. The statistical models developed here were applied to upscale spatially the current thermic conditions across the whole set of lakes and ponds of the Pyrenees.
The authors want to aknowledge the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya and the European Social Fund for the doctoral scholarship FI (2015FI_B_01147) given to the first author, that has allowed this work. The projects provided by the Spanish Government projects; Fundalzoo (CGL2010-14841) and Invasivefish (427/2011) and by the European Commission LIFE+ project LimnoPirineus (LIFE13 NAT/ES/001210), and also the last project of the Spanish Government, FUNBIO (RTI2018-096217- B-I00) supported this research.
With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI).