Fig. 1.
Schematic of sunlit mesocosm units and the planting grid used for spatial arrangement of plant replicates within each mesocosm. (A) Mesocosms are independent units enclosed within clear 8-mil PVC film, and include an evaporative cooler to assist in temperature control, a pollen restriction filter and insect netting to contain pollen and pollinators. Mesocosms contain three replicate soil tubs with 1·2 m2 of soil surface and 0·6 m depth each. Each mesocosm tub was planted with one of three randomly assigned competition treatments. (B) Within each mesocosm tub, an 18-cell planting grid is utilized to arrange the experimental genotypes in a spatially balanced pattern. Competitor plants are added at position 6. The central cell is the location of each tub's independent irrigation system.