Fig 1.
Twenty-four major reservoirs in San Diego County, California, USA http://www.sdcwa.org/san-diego-county-water-sources (http://www.sdcwa.org/reservoirs).
Barret (BA); Cuyamaca (CU); Dixon (DI); El Capitan (CAP); Henshaw (HE); Hodges (HO); Jennings (JE); Loveland (LOV); Lower Otay (LO); Maerkle (MA); Miramar (MIR); Morena (MO); Murray (MUR); Olivenhain (OL); Poway (POW); Ramona (RA); Red Mountain (RD MO); San Dieguito (SN DG); San Vicente (SN VI); Sutherland (SL); Sweetwater (SW); Turner (TR); Upper Otay (UP OT); Wohlford (WF). The black points indicate the three reservoirs we sampled.
Table 1.
Characteristics of three reservoirs sampled weekly from 26 June 2013–26 June 2014.
Fig 2.
(A) Time series of partial pressure of carbon dioxide (pCO2) in ppm for each of the three reservoirs. Current atmospheric concentrations of pCO2 are ~400ppm. (B) pH for each reservoir for 50 sampling weeks. Symbols indicate the reservoir as shown in the legend.
Fig 3.
Partial regression plots of the significant drivers of pH and pCO2 across all reservoirs.
Drivers were identified by the model averaging procedure pH versus (A) total nitrogen (mg N L-1) and (B) bacteria abundance (# L-1), and pCO2 versus (C) zooplankton community biomass (mg L-1) and (D) particulate organic nitrogen (mg N L-1). Symbols indicate the reservoir as shown in the legend.
Table 2.
Variables included in the six top models to predict pH and pCO2.
Fig 4.
Time series of estimated CO2 flux (mmol m-2 day-1).
The four negative values correspond to CO2 flux in Lake Poway that were below the range of the graph during strong wind events.
Fig 5.
Time series for chlorophyll-a (chl-a), total phosphorous (TP), total nitrogen (TN), and particulate organic nitrogen (PON) for the three reservoirs.
(A) chlorophyll-a (μg L-1), (B) TP (mg P L-1), (C) TN (mg N L-1), and (D) PON (mg N L-1). The vertical dashed lines represent dates that received >1 cm precipitation. Precipitation during our study period totaled 14.78 cm, and average annual precipitation in San Diego County is 26.26 cm.
Fig 6.
Time series for (A) dissolved organic carbon (DOC; mg C L-1), and (B) particulate organic carbon concentrations (POC; mg C L-1) for all three reservoirs.
Fig 7.
Time series of bacteria abundance (# L-1) for all three reservoirs.
Fig 8.
Time series for (A) Zooplankton community mean body length (mm) and (B) community biomass (mg L-1) for all three reservoirs.
Fig 9.
Surface (1 m) and bottom (16–20 m) water temperatures (°C) for each reservoir from Sept 2013-June 2014.
The bottom depths for Lakes Poway and Miramar was 20 m and the bottom depth for Lake Murray was 16–17 m. The water columns are stratified when the lines diverge and mixed when the surface and bottom temperatures are the same.