Seeds Obtained by Vacuuming The Soil Surface After Fire Compared With Soil Seedbank in a Flatwoods Plant Community

Abstract

One method of obtaining seeds of native plants may be to let seeds fall to the soil surface and collect them by vacuuming. We evaluated this method by comparing plants that germinated from material vacuumed after fire with plants that germinated from seeds found in cores taken from the top 25 mm (1 in) of soil in a Florida flatwoods plant community before and after fire. A total of 76 species were identified in cores, of which 66 species were found before, and 60 species after, fire. No differences attributable to fire were found for seed density (3261 seeds/m² [2740/yd²]) or concentration in cores (282 seeds/kg [128/lb]). Vacuumed material contained seeds of 58 species (54 in common with cores) with a density of 170 seeds/m² [142/yd²] and a concentration of 451 seeds/kg (204/lb). Species correlations between cores and vacuumed material were significant for 19 of 46 species whose density was > 1/m² in cores. Seeds of 10 species in vacuumed material were common as plants in standing vegetation, but seeds of 13 species (mostly shrubs) growing on the site were not in cores or vacuumed material. Vacuuming the soil surface may be effective for obtaining a diverse supply of seeds for herbaceous plants common on flatwoods after fire. Some species in vacuumed material, however, may not be in proportion to seeds in soil and the vacuumed material will not include seeds of some shrubs that characterize Florida flatwoods communities.