Volume 27, 100

Tropical Grasslands (1993) Volume 27, 100–107

Regeneration and survival of Desmanthus virgatus 78382 in grazed and ungrazed pastures

D.M. BURROWS¹ and F.J. PORTER²

¹Department of Primary Industries, Gayndah, Queensland, Australia
²Biodynamic Research Institute, Powelltown, Victoria, Australia

Abstract

Soil seed reserves, hard seed breakdown, seedling recruitment and plant longevity of D. virgatus CPI 78382 were measured under grazing and in exclosures. Soil seed reserves averaged 150 seeds/m² in grazed and ungrazed areas for most of the study, but increased to 450 seeds/m² in the grazed areas after 3 years. Seed lots placed in the field showed a 40% decrease in hard seed levels over 3½ years. Seedling recruitment was higher under grazing as were adult plant populations. Although plant survival was marginally higher in the exclosures, more than 50% of plants had died 6 months after establishment.