Seasonal changes in the soil hydrological and erosive response depending on aspect, vegetation type and soil water repellency in different Mediterranean microenvironments

摘要

Mediterranean areas are characterized by a strong spatial variability thatmakes the soil hydrological response highly complex. Moreover, Mediterraneanclimate has marked seasons that provoke dramatic changes on soil propertiesdetermining the runoff rates, such as soil water content or soil waterrepellency (SWR). Thus, soil hydrological and erosive response inMediterranean areas can be highly time- as well as space-dependant. This studyshows SWR, aspect and vegetation as factors of the soil hydrological anderosive response. Erosion plots were set up in the north- and thesouth-facing hillslope and rainfall, runoff, sediments and SWR weremonitored. Soil water repellency showed a seasonal behaviour and it waspresented in three out of four microenvironments after the summer,disappearing in the wet season. In general, runoff rate was higher in shrubspatches (0.47 ± 0.67 mm) than in inter-shrub soils (1.54 ± 2.14 mm),but it changed seasonally in different ways, depending on the aspectconsidered, decreasing in the north-facing hillslope and increasing in thesouth-facing one. The main factor determining the hydrological and erosiveresponse was the rainfall intensity, regardless of the rainfall depth of theevent. This response was modulated mainly by SWR in the north-facinghillslope and the vegetation pattern in the south-facing one.