Fire effect on two perennial grasses from northwestern Patagonian grasslands.
GONZALEZ S.; GHERMANDI L.; PELAEZ D.
Lugar: Tokyo; Año: 2014
Abstract Post-fire recovery of perennial plants depends 17 on their capacity to regrow from surviving meristems. 18 Plants are adapted to a particular fire regime, which can 19 be altered by human activities and climatic change. 20 Therefore, predicting the impact of changing fire regimes 21 on post-fire vegetation recovery has become a major 22 ecological concern. We studied the effects of fire tem- 23 perature on survival and growth of the dominant tus- 24 sock grasses Festuca pallescens and Pappostipa speciosa 25 for two post-fire growing seasons in NW Patagonian 26 grasslands. Using a portable propane burner, we applied 27 two fire temperature treatments to individual plants: 28 200?500 C (low temperature) and 500?900 C (high 29 temperature). Plant mortality was higher in F. pallescens 30 than in P. speciosa, possibly due to morphological dif- 31 ferences. Fire damaged active meristems in both species, 32 which delayed emergence of new tillers. This in turn 33 affected leaf length of tillers, which was lower in burned 34 plants during the first growing season. Despite this, 35 growth rate was higher in burned plants once they re- 36 grow only during the first growing season. In summer, 37 post-fire hot and dry conditions affected F. pallescens 38 survival. Although fire temperature affected negatively 39 F. pallescens survival, both tussock grasses recovered 40 quickly after the experimental burns. This response 41 could favour their persistence and dominance in the 42 community. Our study increases understanding of post- 43 fire responses in grasslands and will provide important 44 rangeland management information for grasslands in 45 Patagonia.