Hidric erosion in pinus culture, in forestry road and native grassland

Abstract

Abstract

Santa Catarina is the third Brazilian state in exporting forestry products, with 320,000 hectares (11%) of Brazilian forests. Only in Lages there are 70 millions of pinus trees, and it is the third region with the greater density forested area in the world, just losing to Finland and Sweden. This research had as objective to quantify rainfall erosion during 17 months (from September, 2009 to January, 2011), under natural rain, in pinus reforestation areas with different ages, in a forestry road and natural grasslands, in Campo Belo do Sul/SC - Florestal Gateados Ltda., where the runoff was collected by Coshocton wheels. Water loss by runoff was 6 mm for three years-old pinus, 13 mm for natural grasslands, 23 mm for ten months-old pinus trees and 157 mm for 26 years-old pinus; all of them were considered small due to the rainfall which occurred during the experiment period (2.040 mm); however, in the forestry road, water loss was considered higher (928 mm). In relation to soil losses, those were 8 kg.ha^-1 for three years-old pinus, 28 kg.ha^-1 for natural grasslands, 40 kg.ha^-1 for 26 years-old pinus and 74 kg.ha^-1 for ten months-old pinus trees; all of them were considered small in relation to the tolerance of soil loss; however, in the forestry road, soil loss was considered higher (22.000 kg.ha^-1).

Keywords: Soil and water losses; Coshocton weels; reforestation.