2.3 | Phase II: Phytometer Phase
In June 2020, we germinated seeds of the same four grass species following the procedure outlined above. Eastern redcedar were purchased from Pinewoods nursery, New Jersey. Individual grass and redcedar seedlings were transferred into 2.8 L pots that contained home oraway soils that were either live or sterilized . They were planted in pots using the following method: We added 1.3 L of sterilized sand, then 0.4 L of conditioned training soil from one of the five above-mentioned species, followed by a 0.3 L cap of sterilized sand (Appendix Figure 1). We used a full-factorial design with ten replicates of each phytometer- and conditioned-soil combination, resulting in a total of 500 experimental pots (Figure 1). Grasses were grown in controlled greenhouse conditions for 96 days. Eastern redcedar pots were allowed to grow for 13 months due to their slower growth rate. The maximum height of each plant was measured twice a week for the duration of the experiment. At the end of the experiment, each sample was cut at the root collar and dried in an oven prior to weighing above- and belowground biomass.