Lake Sanabria ecosystem regime shift (1986-2019)

This dataset has been used to study the ecosystem regime shifts of Lake
Sanabria, the largest natural glacial lake in Spain, in a situation of
climate change that may affect compliance with ecological quality
objectives, even with no significant water quality pressures. It comprises
basic data from long-term (1986-2017) and intensive short-term (2015-2017)
limnological monitoring of a few relevant state variables related to
nutrients balance, primary production of phytoplankton and thermal
structure of the water column. Data about recent history of the lake
productivity, reconstructed by high-resolution palaeolimnological analysis
of a surface sediment core, is provided. Time series analysis over several
decades has detected significant conditional heteroscedasticity in the
concentrations of parameters such as chlorophyll and oxygen in recent
years in relation to lake turnover rates, coinciding with exceptional
episodic single-species blooms of some planktonic diatoms. We include
precipitation data, inflow measurements and land use modeling data that
indicate how external nutrient loadings have declined during the last
decades, with reduced precipitation and progressive afforestation of the
catchment, but the lake is shifting to a more productive regime enhancing
the relevance of internal loading and processes.