Fire temperature effects on regrowth of cool-season grasses

ITHURRART L., BUSSO C., TORRES Y., PONCE D, MONTENEGRO O.

BIOCELL

INST HISTOL EMBRIOL-CONICET

Lugar: Mendoza; Año: 2010 vol. 34 p. 96 - 96

0327-9545

Poa ligularis y Amelichloa ambigua are two cool-season perennial grass species which differ in animal preference. Fire and/or grazing history determine abundance of this species in the temperate, semiarid rangelands of central Argentina. The effect of fire temperature was evaluated at the plant center and periphery on regrowth capacity of individually-burned plants of P. ligularis (palatable) and A. ambigua (unpalatable). Burning was conducted on 23 June 2009 within an exclosure, in the Chacra Experimental de Patagones, using a portable burner. Randomly chosen, similar-size plants were burned (n=10). Fire temperature was monitored using 2 thermocouples connected to a data logger placed at the center and periphery of each plant. Burning was conducted in such a way that maximum temperature was maintained at 300 to 500 oC at the plant center. After plant regrowth, on 07 August 2009, the number of green tillers was determined at the center and periphery of each plant. Maximum temperature was similar (p>0.05) in both species. However, temperature was higher (p<0.01) and green tiller number was lower (p<0.01) at the center than at the plant periphery in both species. Regrowth was greater (p<0.05) in P. ligularis than in A. ambigua after burning. Results suggest that low- to intermediate- intensity burnings could be used as a management tool for improving temperate, semiarid rangelands because palatable species would be favored as a result. Nota: solo se presentó un resumen.