Dv. Pelaez et al., EFFECT OF FIRE INTENSITY ON BUD VIABILITY OF 3 GRASS SPECIES NATIVE TO CENTRAL SEMIARID ARGENTINA, Journal of arid environments, 37(2), 1997, pp. 309-317
The effect of fire on axillary bud viability of Stipa tenuis, Piptocha
etium napostaense, and Stipa gynerioides, three important native peren
nial grasses in the semi-arid region of central Argentina, was studied
under different fire intensities: 300-400 degrees C (low fire intensi
ty), 500-600 degrees C (high fire intensity) and no fire (control). Fi
re treatments were applied in April 1994 and May 1995 with a portable
propane plant burner. After each burn the number of dead buds of S. gy
nerioides was higher (p < 0.05) at the centre of the plants than at th
e periphery. Stipa tenuis showed a similar response with the exception
of the 1995 high intensity treatment. No differences (p > 0.05) in mo
rtality were detected between buds located at the centre of the plants
and those at the periphery for P. napostaense in either burn. In gene
ral, the number of dead buds in the high fire intensity treatment was
slightly higher than the number of dead buds in the low fire intensity
treatment in all of the studied species. Treatment effects were simil
ar in S. tenuis, P. napostaense and S. gynerioides. After each burning
date, tillers of plants exposed to fire had more (p < 0.05) dead buds
and fewer (p < 0.05) metabolically active buds than the tillers of co
ntrol plants. Within each fire intensity treatment during both study p
eriods there were no statistical differences (p > 0.05) among species
in the number of total, metabolically active, dormant and dead buds. T
hese results would suggest that fire limits postfire regrowth of S. te
nuis, P. napostaense and S. gynerioides. (C) 1997 Academic Press Limit
ed.