DISTRIBUCIÓN ESPACIAL Y TEMPORAL DE LA PRECIPITACIÓN Y LA HUMEDAD DEL SUELO EN TRES SITIOS FORESTALES DE LA VIII REGIÓN DE CHILE (Spatial and temporal distribution of precipitation and soil water content at three forest sites of the VIII Region of Chile)

In Chile there are around two million hectares with forest plantations, the VIII Region being noteworthy, for its favorable climatic conditions. Considering the importance that the hydric regime has on these species, the objective of this study was to characterize the precipitation and soil water content in three sites representative of the Coastal Dry Land, Central Valley and Andean Foothills of the region. The selected sites are located between 37°00 and 37°45? S. lat. and 72°00 and 73°10 W. long.. The temperature, rainfall and soil water content were recorded from September 1993 to August 1996. The results indicate that the monthly rainfall in the Andean Foothill site was not statistically different from that registered in the Central Valley and the Coastal Dry Land. The same situation was observed with the mean temperatures. Nevertheless, although temperatures and rainfall were the same in all sites, significant differences were found when comparing the soil water contents. The soil water content in the Andean Foothill site was on average 420 and 440% greater than those observed in the Central Valley and the Coastal Dry Land, respectively. The higher organic matter level in the Andean Foothill site would be the main cause of this phenomenon. This higher water availability was translated into higher rates of growth in the forestry plantation. The results obtained demonstrate the utility of characterizing forest sites through available soil water instead of rainfall