Monday, November 13, 2006 - 10:45 AM

Soil and Silvicultural Treatment Effects on Belowground Biomass Distribution of Radiata Pine in Chile.

Rafael Rubilar1, Howard Allen2, Jose Alvarez3, and Tim Albaugh2. (1) Fac. Cs. Forestales, Univ de Concepción, Victoria 631, Casilla 160C, Concepción, Chile, (2) Forest Nutrition Cooperative, North Carolina State Univ, 225 Winding Ridge Dr, Cary, NC 27511, (3) Forestal Mininco S.A., Av. Alemania 751, Los Angeles, Chile

Coarse and fine roots biomass and distribution in depth estimates for young radiata pine plantations were obtained for different silvicultural treatments from two trials established under constrasting soil textural characteristics. Large differences in biomass allocation and distribution were observed for these second rotation sites. Belowground biomass estimates were larger in proportion to aboveground biomass at the sandy site. Large differences in coarse, and fine root distribution, were observed between sites but not among silvicultural treatments applied. Differences in root distribution and morphology were predominatly observed at the sandy soil site. Silvicultural treatments differences at the sandy site were attributed to large differences in particle size distributions on the soil profile of the coarse textured sandy soils. Differences in root morphology among silvicultural treatments did not have an effect on aboveground biomass accumulation. Root channels from the previous rotation stand may explain the lack of effect of the observed differences in root morphology in aboveground biomass accumulation among treatments.