DOI: 10.5061/dryad.6wwpzgmx9
title: Data to Prior exposure to stress allows the maintenance of an ecosystem cycle following severe acidification

description: This freshwater mesocosm study was conducted in
 19 out of 110 mesocosms at the Large Experimental Array
 of Ponds (LEAP) at the Gault Nature Reserve in
 Mont-St-Hilaire, QC, Canada (45°32' N, 73°08' W, 122 m a.s.l.)
 between May and October 2018 for a total of 147 days. On 24 May
 2018, the mesocosms (1100L stock tanks, Rubbermaid,
 Huntersville, NC, USA) were filled with approximately 1000 liters of
 unfiltered lake water via a pipeline from oligotrophic
 Lac Hertel, located 1 km upstream of the experimental facility. 
 These data consist of two datasets that were used for
 our paper.  Dissolved oxygen as measured with data loggers
 (MiniDOTs, PME, Vista, California, USA) in 12 mesocosms Phytoplankton
 biomass as measured with a FluoroProbe (bbe Moldaenke, Schwentinental,
 Germany) in 19 mesocosms
description: <strong>Dissolved oxygen</strong>
 We tracked DO dynamics in twelve mesocosms using data loggers
 (MiniDOTs, PME, Vista, California, USA) attached to the side of the
 mesocosms at a depth of approximately 20 cm from May to October 2018.
 Water temperature (°C) and DO (in mg/l) were measured every 20 minutes for
 145 days in 2018. Four loggers were in mesocosms at pH 5.5, four at pH 6.5
 and four at pH 8.5. All analyses focused on temperature-corrected values
 of DO (in % saturation). Outlier values &gt; 4 standard deviations
 away from the mean DO across all data points (98 % DO saturation) were
 attributed to temporary probe disturbance or malfunction and were thus
 excluded from analyses of DO across time and mean DO per phase (but not in
 the wavelet analysis). These values (DO saturation &lt; 40 % or
 &gt; 150%) represented 0.4 % of all data points.
 <strong>Phytoplankton biomass</strong>
 We measured total phytoplankton community biomass in the twelve
 mesocosms with the DO loggers throughout the experiment, albeit at a much
 lower temporal resolution than DO (twice per week) from June to
 October 2018. In addition, we measured chlorophyll a in additional seven
 control mesocosms, which were positioned at the side of the experimental
 array. These control mesocosms maintained their base line pH throughout
 the entire experiment, even during phase 2 and, therefore, represent a
 temporal control. 2L of mesocosm water was sampled from across the water
 column and chlorophyll a concentration in a subsample was determined
 fluorometrically with a FluoroProbe (bbe Moldaenke, Schwentinental,
 Germany). 2L of mesocosm water was sampled from across the water column
 and chlorophyll a concentration in a subsample was determined
 fluorometrically with a FluoroProbe (bbe Moldaenke, Schwentinental,
 Germany). Through the excitation of chlorophyll a and accessory pigments
 with various LEDs, the Fluoroprobe detects the biomass (ug/L) of four
 'spectral groups' that roughly correspond to main phytoplankton
 taxa: (i) ‘green’ algae (Chlorophyta and Euglenophyta), (ii) ‘brown’ algae
 (Bacillariophyta, Chrysophyta and Dinophyta), (iii) ‘blue’ algae
 (Cyanophyta) and (iv) ‘red’ algae (Cryptophyta). Sampling started on day 1
 (14 June, 2018) and ended on day 147 (17 October, 2018) for a total of 23
 sampling points. Chlorophyll a concentrations &gt; 80 µg / liter
 (n=21) were attributed to a faulty reading of the fluoroprobe and were
 thus excluded from analyses.
description: For the paper, we only used a subset of the phytoplanktion data
 (i.e., fluoroprobe.csv). We used this line of code to subset the
 dataset. selected &lt;- c("A4",
 "A5", "A6", "D4", "D5",
 "D6", "J4", "J5", "J6",
 "K4", "K5", "K6", "CL1",
 "CL2", "CL11", "CL3", "CL4",
 "CL5", "CL6")<br> d&lt;- df[df$pond %in%
 selected,]