Seedbed ecology and emergence of Lehmann lovegrass (Eragrostis lehmanniana Nees) as influenced by burning

Lehmann lovegrass (Eragrostis lehmanniana Nees) is a warm-season bunchgrass native to South Africa which dominates many desert grasslands in southern Arizona. To determine why fire results in high seedling recruitment of this species, seedbank germination and field seedling emergence were measured in relation to (1) no treatment, (2) burning, (3) clipping and herbicide and (4) herbicide only. Treatments were replicated over 2 years on a stand of Lehmann lovegrass at the Santa Rita Experimental Range. Canopy removal, by either clipping or burning, significantly increased seedling emergence in seedbank bioassays prior to summer rains both years. Bioassay emergence was 826, 415, 350 and 199 seedling/m2 in 1988 from the dead-clip, burn, dead-standing and control treatments, respectively. Field seedling emergence was significantly increased with canopy removal both years and seedling densities were 281, 142, 3, and 0.1 seedlings/m2 for the dead-clip, burn, dead-standing and control treatments, respectively in 1988. The ability of this grass to reestablish after canopy disturbance may result from a greater range in sol temperatures and increases in red light reaching the seedbed