Metadata

Sampling Description
We haphazardly selected three replicate points at each of the sites along each transect for periphyton collection and environmental measurements. At each of the 3 replicate points, surface (SW) and porewater (PW) conductivity (mS cm-1) were measured with a YSI 30 Pro meter (Yellow Springs Inc., Yellow Springs, Ohio), water depth (cm) was measured by placing a meter stick on the soil surface and measuring to the surface of the water column, and soil depth (cm) was measured by inserting a steel rod into the soil until it hit bedrock and measuring the length of rod to the soil surface. Periphyton mats were harvested from a 1 m2 quadrat at each replicate point and placed in a perforated graduated cylinder to drain excess water and measure total mat biovolume. A 120 mL subsample of the total harvested material was placed in a sample bag, transported back to the laboratory on ice, and stored in a -20°C freezer until processed. Samples were thawed and transferred to a clean dish where plant material, rocks or other fragments were removed using forceps. The clean periphyton was relocated to a 500-mL beaker and homogenized with a hand-held blender. The volume of the homogenized sample was recorded to account for dilution with deionized water (DI) water used to facilitate cleaning and homogenizing the sample. The beaker was placed on a stir plate and subsampled for biomass, chlorophyll-a, total phosphorus, and diatom assemblage composition (Mazzei and Gaiser in press Ecological Indicators)

Method Step