Herbaceous vegetation response to controlled fire and postfire defoliation in a semiarid rangeland of Argentina

BLAZQUEZ, FRANCISCO R.; ELIA, OMAR R.; PELÁEZ, DANIEL V.; ANDRIOLI, ROMINA J.

ARID LAND RESEARCH AND MANAGEMENT

TAYLOR & FRANCIS INC

Año: 2017 vol. 31 p. 446 - 461

1532-4982

Semiarid rangelands of central Argentina are shaped by fire andgrazing. The aim of this study was to quantify the effect of controlledfire on aboveground biomass production of (1) herbaceous species asa whole group and (2) herbaceous species subclassified as desirable orundesirable perennial grasses and as herbaceous forbs at the end oftwo growing seasons after an experimental fire in a semiaridrangeland of central Argentina. The effect of the length of the restingperiod after fire on aboveground biomass production of desirableperennial grass species was also assessed; treatments consisted indefoliations at the end of the first and second postfire growingseasons, at the beginning and at the end of the second postfiregrowing season and only at the end of the second postfire growingseason. Total biomass production of the burned treatments washigher than that of the control treatment, the difference beingattributed to an increase in desirable perennial grass species biomass.This in turn was negatively affected by defoliation at the end of thefirst postfire growing season, suggesting that the beneficial effect offire on biomass production might have been overridden by the stressimposed by an early defoliation. Overall, the results of the presentstudy suggest that grazing should be held back for at least a wholeyear after the fire to achieve the pursued aim of increasing forageproduction by the use of controlled fire