Effect of fires on soil nutrient availability in an open savanna in Central Brazil

Autor(es)

Pivello, Vania Regina ^[1] ; Oliveras, Imma ^[1] ; Miranda, Heloisa Sinatora ^[2] ; Haridasan, Mundayatan ^[2] ; Sato, Margarete Naomi ^[2] ; Meirelles, Sergio Tadeu ^[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-70904970 Brasilia, DF - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLANT AND SOIL; v. 337, n. 1-2, p. 111-123, DEC 2010.
• Citações Web of Science: 37

Resumo

Fire is common in savannas but its effects on soil are poorly understood. We analyzed long-term effects of fire on surface soil of an open Brazilian savanna (campo sujo) in plots submitted to different fire regimes during 18 years. The five fire regimes were: unburned, quadrennial fires in middle dry season, and biennial fires in early, middle or late dry season. Soil was collected during the wet and the middle dry season of 2008, and analyzed for pH, organic matter, total N, potential acidity, exchangeable cations and available P, S, Mn, Cu, Zn and Fe. We applied multivariate analysis to search for patterns related to fire regimes, and to local climate, fuel, and fire behavior. Spearman test was used to establish correlations between soil variables and the multivariate analysis gradient structure. Seasonal differences were tested using t-test. We found evidence of long-term fire effects: the unburned plot was segregated mainly by lower soil pH; the quadrennial plot was also segregated by lower soil pH and higher amount of exchangeable cations; the time of burning during the dry season in biennial plots did not significantly affect soil availability of nutrients. Differences in elements amounts due to the season of soil sampling (wet or dry) were higher than due to the effect of fires. Higher availability of nutrients in the soil during the wet season was probably related to higher nutrient inputs via rainfall and higher microbial activity. (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