Texas Blackland Prairie restoration on old-field vegetation using seeding, mowing, and burning

Abstract

This study compares degraded old-field grass-dominated pasture response to over-seeding with native tallgrass prairie species with the management practices of burning, mowing and a no-treatment control. Treatments were randomly allocated in a 2 × 3 factorial design with at least six replicate 40 m × 40 m plots. In the third year after treatment species richness increased for seeded vs. unseeded plots (18.9 vs. 14.4 species per plot; p < 0.01) and for mowed or control vs. burned plots (17.4 vs. 15.2 species per plot; p < 0.05). Also, tiller densities of planted tallgrasses increased somewhat to 12% of old-field grass tiller densities (p = 0.001). Multivariate analysis (ANOSIM) the third season following planting indicated some dissimilarity between seeded and unseeded plots (R = 0.32; p = 0.002). After 9 years dissimilarity between seeded and unseeded communities had increased (R = 0.83; p = 0.001) but species richness was similar (p > 0.27). Seeded tallgrasses comprised 44% biomass in seeded vs. 3% in unseeded plots, while seeded forbs comprised 16% biomass in seeded vs. 4% in unseeded plots (p < 0.01). Multivariate analysis of seeded-burned and seeded-mowed sites indicated some dissimilarity (R = 0.25; p = 0.002) with tallgrass biomass being 55% greater (p = 0.001) on mowed sites than controls and 117% greater than burned sites. Tallgrass prairie species planting success may be enhanced with well-timed mowing but harmed by burning when plants are young.