## 3 Results
### Regulation of Lake Metabolism  
With respect to the average weekly metabolism rates, in LS lake GPP, R, and NEP were positively correlated with water temperature and wind speed during the study period. Moreover, R and GPP were also positively correlated with the conductivity. Finally, R was negatively correlated with lake  
Figure 4: Calculated daily and monthly GPP: Gross primary production, R: community respiration, and NEP: net ecosystem production values for the (**a–d**) La Salada and (**e–h**) Sauce Grande lakes. Gaps correspond to periods of replacement or cleaning and calibration of the sensors.  
volume, and NEP was positively correlated (Figure 5). In the case of SG lake, GPP and R were positively correlated with water temperature and negatively correlated with lake volume, whereas NEP was positively correlated (Figure 6). The environmental variables measured monthly (e.g., TP, TNorg, Chl \(a\), etc.) were not included in the statistical analysis because of the small number of measurements. From multiple regression analyses the variables that best described the metabolism rates from the daily measurements were the water temperature, wind speed, and lake volume for both lakes (Table 3).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Lake** & **Dependent Variable** & **Parameter** & \(\mathbf{R^{2}}\) & \multicolumn{2}{c}{**Standardized**} & \(\mathbf{t}\) & \(\mathbf{P}\) \\  & & & & & **Regression Coefficient** & \(\mathbf{t}\) & \(\mathbf{P}\) \\ \hline \multirow{6}{*}{La Salada} & \multirow{6}{*}{R} & Temp & & 0.51 & 1.32 & \textless{}0.0001 \\  & & Wind & 0.392 & 0.50 & \(-0.12\) & \textless{}0.0001 \\  & & Vol & & \(-1.50\) & \(-294.61\) & \textless{}0.0001 \\  & & Temp & & 0.50 & 1.09 & \textless{}0.0001 \\  & & Wind & 0.299 & 0.49 & \textless{}0.19 & \textless{}0.0001 \\  & & Vol & & \(-1.50\) & \textless{}0.73\) & \textless{}0.0001 \\  & & Temp & & 0.50 & 2.42 & \textless{}0.0001 \\  & & Wind & 0.362 & 0.50 & \(-0.29\) & \textless{}0.0001 \\  & & Vol & & \(-1.50\) & \(-831.22\) & \textless{}0.0001 \\ \hline \multirow{6}{*}{Sauce Grande} & \multirow{6}{*}{R} & Temp & & 0.4 & 0.91 & \textless{}0.0001 \\  & & Wind & 0.255 & \(-0.09\) & \(-0.68\) & \textless{}0.0001 \\  & & Vol & & \(-1.34\) & \(-4.80\) & \textless{}0.0001 \\  & & Temp & & 1.1 & 1.29 & \textless{}0.0001 \\  & & Wind & 0.302 & \(-0.72\) & \(-0.57\) & \textless{}0.0001 \\  & & Vol & & 0.57 & 0.74 & \textless{}0.0001 \\  & & Temp & & \(-0.35\) & 2.30 & \textless{}0.0001 \\  & & Wind & 0.314 & \(-0.57\) & \(-1.14\) & \textless{}0.0001 \\  & & Vol & & 1.49 & 31.14 & \textless{}0.0001 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Multiple regression analysis for GPP: Gross primary production, R: community respiration, and NEP: net ecosystem production as a function of Temp: water temperature (\({}^{\circ}\)C), Wind: wind speed (m s\({}^{-1}\)) and Vol: lake volume (m\({}^{3}\) seg\({}^{-1}\)) in the La Salada and Sauce Grande lakes during the study periods.  
Figure 5: Correlation matrix relating the weekly averages for metabolic variables GPP: Gross primary production, R: community respiration, and NEP: net ecosystem production (mmol m\({}^{-3}\) day\({}^{-1}\)) with the environmental variables Temp: water temperature (\({}^{\circ}\)C), Vol: lake volume (m\({}^{3}\) seg\({}^{-1}\)), Cond: electrical conductivity (mS cm\({}^{-1}\)), and Wind: wind speed (m s\({}^{-1}\)) for the La Salada lake during the study period.