Effects of fire regimes on herbaceous biomass and nutrient dynamics in the Brazilian savanna

Autor(es)

Oliveras, Immaculada ^[1] ; Meirelles, Sergio T. ^[1] ; Hirakuri, Valter L. ^[2] ; Freitas, Cenira R. ^[2] ; Miranda, Heloisa S. ^[2] ; Pivello, Vania R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Dept Ecol, BR-05508090 Sao Paulo - Brazil

^[2] Univ Brasilia, Inst Ciencias Biol, Dept Ecol, BR-70919970 Brasilia, DF - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF WILDLAND FIRE; v. 22, n. 3, p. 368-380, 2013.
• Citações Web of Science: 15

Resumo

This study explores the long-term effects of fire treatments on biomass and nutrient pools in an open savanna from Central Brazil. Treatments included early, middle and late dry season burns every 2 years, a middle dry season burn every 4 years, and protection from fire on five 4-ha plots. We quantified aboveground biomass of graminoids and forbs/sub-shurbs, and their nutrient concentrations and stocks in both dry and wet seasons, and below-ground biomass down to 30-cm depth. We found strong differences between wet and dry season, with biomass and nutrient concentrations being highest in the wet season, across all fire treatments. Fire treatments had significant effects on plant nutrient stocks and root distribution, although total biomass was not affected. Concentrations of the most volatile nutrients (N, S, K and P) were higher in the herbaceous aboveground biomass of the quadrennial and the unburnt plots, suggesting that increases in fire frequency would reduce the amount of nutrients in aboveground biomass and increase the concentration of fine roots at the soil surface. Results highlight the role of fire in maintaining community dynamics in the Brazilian savanna. Overall, the quadrennial burn appears to be the optimal fire regime in open Cerrado vegetation. (AU)

• Processo FAPESP: 06/61570-5 - Herbaceas invasoras do cerrado: investigacao de interacoes com o meio fisico, o fogo e a comunidade nativa para subsidiar seu manejo.
• Beneficiário: Vânia Regina Pivello
• Modalidade de apoio: Auxílio à Pesquisa - Regular