Loblolly pine seedling response to competition from exotic vs. native plantsThis article is part of a larger document. View the larger document here.
A field study was conducted in Santa Rosa County, FL to test the hypothesis that an exotic understory would exert a higher degree of competition on tree seedling establishment and growth than native vegetation. The study site was a 60 ha cutover area infested with the invasive exotic cogongrass [Imperata cylindrica (L.) Raeusch.]. A completely randomized design was set up with five replications of three treatments: (1) control- plots that were kept weed free, (2) plots with only native vegetation, and (3) cogongrass infestation. On March 6, 2003, 1-year-old bare-root loblolly pine seedlings were planted at 1.8 x 1.1 m spacing, and initial root collar diameter (RCD) and height were measured. The seedlings were harvested in December, and final RCD, height and above- and below-ground biomass were measured. Seedlings had the lowest biomass growth in the cogongrass treatment and the highest in the control. The results of the study demonstrate that the exotic cogongrass is far more competitive than native vegetation.