Prescribed burning effects on soil physical properties and soil water repellency in a steep chaparral watershed, southern California, USA

Influência do Sistema de Corte e Queima na Infiltração e Condutividade Hidráulica do Solo

“…Os efeitos deste sistema sobre as propriedades físico-hídricas do solo ainda são controversos (LAWRENCE et al, 2010), mas nos últimos anos muitos pesquisadores tem considerado este um sistema não sustentável (STYGER et al, 2007;ARE et al, 2009;THOMAZ et al, 2014), pois seus efeitos benéficos, como: redução de plantas daninhas, liberação imediata de nutrientes (Niemeyer et al 2005), aumento da atividade biológica e aumento da matéria orgânica parecem ser de curta duração devido aos seus efeitos degenerativos nas propriedades físicas do solo (WUEST et al, 2005;HUBBERT et al, 2006). Devido ao aumento na pressão de uso da terra o tempo de regeneração (pousio) destas áreas vem sendo reduzido.…”

Assessment of Site and Soil Characteristics of Rill Erosion Following the Lockheed Fire in the Little Creek Watershed, Swanton Pacific Ranch

“…Because of varying depths of the organic material, temperature of fire heating the soil and the length of time the fire persists on the ground; generally water repellency strength will increase as the depth increases. In California chaparral vegetation, it was observed that the amount of organic material spacing of vegetation played a role in the water repellency variation and depth of the wetted layer occurring in the soil (Hubbert et al, 2006). WDPT was measured at the surface, 2cm and 4cm depths; the results illustrated an increase in water repellent at lower subsurface depths of 4cm from pre-fire to post-fire conditions.…”

“…(Lloret and Zedler, 2009). The vegetation is predominately drought tolerant, and has adapted by leaf drop and the development of waxy leaf surfaces to retain moisture and prevent water loss through transpiration, thus creating a high resin content of the organic material (DeBano, 1981;Hubbert et al, 2006). The resin produced by the shrubland vegetation has over time created a natural water repellent soil.…”

“…This is the amount of time it takes a water droplet to adsorb into the soil. WDPT is determined when the droplet has changed from a convex shape to flat on the soil surface, and infiltration has occurred (Hubbert et al, 2006). Approximately 10 to 20 droplets are applied to the soil mineral surface at depths ranging from 0 to10 cm.…”

“…The common repellency index is a standard classification used by researchers, which indicates the class intervals in seconds associated with the repellency persistency rating (Doerr et al, 2006). The modified water repellency index used; 0-1 second = non repellent, 1 -5 seconds = very low repellency, 5 -30 seconds = low repellency, 30 -180 seconds = moderate repellency, and > 180 seconds = extreme repellency (Hubbert et al, 2006).…”