Seasonal changes of pore size distribution in a soil with different forest use

Abstract

Seasonal volumetric changes of pore morphology was determined in Hapludand soil profiles of Southern Chile under native forest, pasture and afforestations with Pinus radiata in first and second rotation. The changes among pore space depends on soil use, it is greatest in the places with exotic forest and smallest in the soil under native forest. Significant changes were observed in the pore size distribution. In summer, coarse pores in the upper layers increase, in contrast to the medium pores in the site under native forest. With an afforestation with Pinus radiata the seasonal changes of porosity were significant. The coarse pores collapsed to medium and fine pores. With a second afforestation of pine the intensities of seasonal changes of porosity decreased. Slow seasonal changes of pore space properties were observed in the site under pastures. The changes of pore characteristics depend on structure stability and intensity of rootness.