## 3 Results
### Lake Metabolism  
In the LS Lake, GPP and R showed daily and seasonal variations, with R exceeding GPP during most of the study period (Figure 4). The mean monthly R value (17.21 mmol O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\)) slightly exceeded the mean monthly GPP value (16.61 mmol O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\)) (Figure 4d) presenting a GPP/R ratio of 0.91. Monthly GPP ranged between 6.32 mmol O\({}_{2}\) m\({}^{-3}\) in June 2014, and 29.1 mmol O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) in January 2014. GPP presented a seasonal pattern increasing during summer and spring and decreasing during autumn and winter (Figure 4a,d). Temporal variation in R presented a similar pattern and was positively correlated with GPP (Figure 5). The minimum monthly R value was 8.35 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) during June 2014 and the maximum value was 30.8 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) in January 2014 (Figure 4b,d). NEP monthly values varied between \(-\)7.0 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) during April 2014 and 3.5 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) during December 2014. NEP < 0 occurred during most of the study period except during spring of 2014 (Figure 4c,d). Mean monthly NEP value was \(-\)1.1 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) classifying LS as a heterotrophic lake during the study period. Fourier analysis showed maximum densities on monthly, 11-day and weekly scales, and minor scales at 3 days for the three metabolic variables. With regard to the environmental variables, the water input, water temperature, wind speed, and conductivity coincide with these scales, whereas the water volume only showed maximum densities on the monthly scale.  
In SG lake GPP and R also showed daily, and seasonal variations, with R showing greater or similar values with respect to GPP (Figure 4). The mean R value was 13.9 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\), and the mean GPP value was 12.6 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) presenting a GPP/R ratio of 0.93. Monthly GPP ranged between 8.1 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) during October 2016 and 21.2 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\) during March 2017 (Figure 4h). GPP showed a seasonal pattern with maximum values during summer of 2017, decreasing towards colder months. R presented a similar seasonal pattern (Figure 4f,h) with minimum values during October 2016 (7.2 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\)) and maximum during March 2017 (25.8 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\)). Both variables were positively correlated (Figure 5). The NEP mean value during the study period was \(-\)1.25 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\), with NEP < 0 during most of the study period, classifying SG as a heterotrophic lake (Figure 4g,h). Minimum NEP values were recorded during March 2017 (\(-\)4.1 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\)) and maximum during October 2017 (0.9 O\({}_{2}\) m\({}^{-3}\) day\({}^{-1}\)) (Figure 4h). Fourier analysis showed maximum densities on monthly, 11-day and weekly scales and minor scales at 3 days for the three metabolic variables. These coincide with the maximum densities found in the water input, DO, wind speed, and water temperature, whereas the lake volume only presented maximum values on the monthly scale and conductivity on the monthly and 10-day scales.