Table 2. Summary of physicochemical data collected at Lakeside Drive in 2010.

Date range in 2010	Dominant phase
	Gallionellales	Transition	Leptothrix ochracea
	4/3–5/3	5/6–5/23	5/26–9/30
Biomarker quantification
% Stalks	30.0±7.5	19.4±3.7	2.6±1.2
% Sheaths	10.8±5.0	40.8±3.0	68.7±0.1
Physical parameters
Water temperature (°C)	11.6±1.4	13.1±2.4	15.7±1.4
Raina (cm hr−1)	0.12±0.18	0.56±0.73	1.0±0.95
Gross chemical parameters
Change in oxygen with depth from the  surface of the matb	[O2] =−50(x) μM cm−1+139 μM R2=0.94	not determined	[O2] =−4(x) μM cm−1+39 μM R2=0.76
pH	6.1±0.5	5.2±0.5	5.2±0.2
Dissolved ferrous iron (μM; passed through  a filter of 0.2 μm in size)	7±7	59±27	89±70
DOC (mg l−1)	4.8±1.5	7.3±0.1	7.1±1.3
Spectral slope ratio	1.005±0.021	1.081±0.057	1.128±0.107
Major conservative elemental constituentsc
Na	5.26±4.13	0.00±0.00	1.34±1.74
Mg	64.0±32.7	23.4±4.6	57.8±41.1
K	52.4±34.1	26.2±24.6	23.5±20.3
Ca	67.2±21.5	33.1±11.8	53.4±22.4
Cl	126.9±124.1	20.7±1.8	30.0±9.5
Al	3.0±1.0	1.7±0.7	2.8±1.3
Biologically active redox elementsc
P	0.3±0.2	1.0±0.9	0.9±0.5
S	55.9±19.3	16.3±5.5	24.4±14.1
Mn	1.6±1.3	2.3±0.9	10.1±10.9
Fe	5.0±4.0	7.3±2.4	22.8±14.4
Ni	0.04±0.02	0.03±0.04	0.009±0.01
Cu	0.6±0.4	1.4±1.7	0.2±0.3
Zn	0.3±0.08	0.7±0.7	0.02±0.1

Abbreviation: DOC, dissolved organic carbon.

^aAverage rain rate during storm.

^bWhere [O2]=oxygen concentration (μM) and x=depth (μM cm⁻¹) into the mat from the surface with (n=4 or 3, respectively).

^cElemental concentrations are in μM.