Data/hora: 24/06/2024 15:46:36

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 05/06/1995
Data da última atualização: | 05/04/2017
Autoria: | BUSH, D. E.; SMITH, S. D.
Título: | Effects of fire on water and salinity relations of riparian woody taxa.
Ano de publicação: | 1993
Fonte/Imprenta: | Oecologia, v.94, n.2, p.186-194, 1993.
Idioma: | Inglês
Conteúdo: | Water and salinity relations were evaluated in recovering burned individuals of the dominant woody taxa from low-elevation riparian plant communities of the southwestern U.S. Soil elemental analyses indicated that concentrations of most nutrients increased following fire, contributing to a potential nutrient abundance but also elevated alluvium salinity. Boron, to which naturalized Tamarix ramosissima is tolerant, was also elevated in soils following fire. Lower moisture in the upper 30 cm of burned site soil profiles was attributed to shifts in evapotranspiration following fire. Higher leaf stomatal conductance occured in all taxa on burned sites. This is apparently due to higher photosynthetic photon flux density at the midcanopy level and may be partially mitigated by reduced unit growth in resprounting burned individuals. Predawn water potentials varied little among sites, as expected for plants exhibiting largely phreatophytic water uptake. Midday water potential in recovering Salix gooddingii growing in the Colorado River floodplain reached levels which are considered stressful. Decreased hydraulic efficiency was also indicated for this species by examining transpiration water potential regressions. Recovering, burned Tamarix and Tessarica sericea had enriched leaf tissue relative to unburned controls. Higher water use efficiency following fire in these taxa may be attributed to halophytic adaptations and to elevated foliar nitrogen in Tessaria. Consequently, machanisms are proposed which would facilitate increased community dominance of Tamarix and Tessaria in association with fire. The theory that whole ecosystem processes are altered by invading species may thus be extended to include those processes related to disturbance.
Palavras-Chave: | Efeito; Effect; Fire; Grassland.
Thesagro: | Água; Carbono; Fogo; Pastagem; Queimada; Solo.
Thesaurus Nal: | burning; carbon; soil; water.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (28109-1) - ADD - SP - PP - SP14332 -  - 14332 - DIS