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Methods for Experiment 303 -

aiae303 - Aboveground peak biomass

Biomass Clipping Protocol

Locate the two flags and slide the clipping pole into the plot so that it is directly in between the two flags to aid in cutting the straightest line possible. Make sure that there is not biomass underneath the meter stick. Place the hedge clipper at one end of the clipping pole so that the clippers are on the east side of the clipping pole (figure 1). Clip the biomass along the clipping from one flag to the other. Keep the clippers approximately 1cm above soil level. Cut only the plants rooted in the 100cm by 10cm clip strip. As you are clipping pull the clipped biomass out of the plot and carefully place it in a tray. Fold any biomass that is too tall for the tray. Make sure that no biomass is hanging out of the tray. Rake your hands through the biomass on either side of the clip strip to find any cut biomass that has not been placed in the tray. Collect all of the litter that is lying on the ground in the strip and place it into the tray. If one tray gets full, place the rest of the biomass in a second tray. When the plot has been clipped, place an empty tray over each tray that contains biomass. Using the tray labeling paper, record the date, your initials, the number of trays containing biomass for this plot, and the plot number onto the paper and place the paper into the tray with the biomass. Make sure to do this for each tray that is filled with biomass if there is more than one tray per plot. Take the finished trays to the vehicle and place them in the pile of filled trays. Check the plot off on the check-off sheet and proceed to the next plot. Before leaving make a final sweep to make sure that all plots were clipped.

Biomass Weighing Protocol

Open the E303 Aboveground Harvest weigh program. Use at least a 2 point scale for this (0.00). Tare the scale with a weighing tub on it. Weigh the sample. If it requires multiple weighings, add up the weights and just record the final weight. If there is sand in the samples, sieve the sample to remove the sand. Sand weighs significantly more than biomass so it is important to remove as much of the sand as possible from the sample. There is a computer program that records all of the weights. If you accidentally enter a weight that is not supposed to be there make notes in the notes section about which weight is correct. Also make sure to record the weights by hand on the datasheets. After weighing the sample, place it back in the bag. Be careful not to lose any of the sample because we may have to re-weigh it. Put the plot bag into a large clear garbage bag and record the plot number on the logging sheet for that plastic bag. Make sure that the garbage bag is labeled with the experiment number, what is in the bag, and the date.

aibe303 - Continuous Soil Moisture and Temperature

Missing data

Missing values (NA) are exncluded where sensors became disturbed or disconnected from the data logger and stopped collecting data.

Sensors

Meter Group, Inc. USA: 5TM Soil Moisture and Temperature sensor and EM50 Data Logger

VWC and Temp collection

Obtain the correct number of probes, 1 per subplot and 4 per plot. One data logger is needed per plot Replace batteries in the data logger before deploying. Set up the data logger by connecting to a computer with the cable and using the ech20 software to rename the data logger as the new plot number and set the correct date, time, and experiment number. Use the sheet of paper on the left hand side of the data logger to: Label the data logger with the plot number and date of deployment Label each port with a corresponding subplot - this is the ONLY way to tell which subplot corresponds with which port, so it???s very important to label and stick to the labeling scheme. If the paper is already filled on both sides, replace it but keep the old piece of paper in the data logger. Take a picture of the new sheet of paper when you are done. Make sure the probe goes into the correct subplot corresponding with the label. Place the probe approximately in the center of the subplot, but shifted toward the inside of the full plot to avoid being directly under a heat lamp that would block all rain. Gently insert the probe vertically into the soil using both hands. Avoid wiggling the probe back and forth as this can create air pockets around the sensors that may influence the reading. Push the probe in until the prongs are fully in the soil and the bottom of the handle is flush with the soil. Use 2 zip ties to fasten the data logger to a leg of the scaffolding infrastructure in the middle of the plot. Make sure that probes are securely plugged into the data logger and double check that each port contains the correct probe.