Changes of forest soil structure with different managements

Abstract

An evaluation of the effect of management (native forest, pasture, afforestation with Pinus radiata) in first and second rotation on volumetric properties of Hapludand soil profiles located in Loncoche, Southern Chile was carried out.
The reference to evaluate the amount and course of changes was the soil under the native forest. Undisturbed soil samples were taken for to determine volumetric soil components. Settlement of the soil was detected through the decrease of pore volume after the native forest was eliminated. The pasture presented the highest settlement of increase with the number of afforestations. The effects of soil management were reflected in pore size distribution.
The loss of pore volume goes together with a decrease of large pores and an increase of small pores. The structural degradation of afforestation sites involves intermedíate soil layers. On the site under pasture the coarse pores diminish in the upper layers. Recently incorporate soil sites to production use, show primary consolidation curves. With an increment of soil management intensity the consolidation curves were secondary and marked an increase of bearing capacity.