Soil propiertes and forest quality in lenga forest of Tierra del Fuego, Argentina: does a relation exist?

MORETTO, A.; PANCOTTO, V.; NOVOA MUÑOZ, J.; PONTEVEDRA POMBAL, X.; ESCOBAR, J.

Branca

Conferencia; Forest Landscapes and Global Change; 2010

IUFRO

Nothofagus pumilio (lenga) forest is the most important timber species in the southern part of Patagonia. The volume and timber production change according the site quality, which is mainly determined by the height of the dominants trees. The objective of this work is to evaluate soil chemical properties in sites of forest with different timber quality. We selected three stands of lenga forest according to the site index (1=high to 5=low) in Tierra del Fuego, Argentina. We measured soil chemical properties in the first 10cm of the organic soil of a high (1.5), intermediate (2.5), and low timber quality site (3.5) (21, 18, and 15m mean timber height, respectively) with similar topography characteristics. We found a higher total Nitrogen, organic matter, and %C in soils of forest with high timber quality in comparison to sites of intermediate and low quality. However Phosphorus was higher in the site with low quality respect the stands of intermediate and high quality, maybe associated to the high mobilization of phosphorus at low pH, as we found in the low quality site. According to this pattern high quality timber stands grow in soils with high fertility, and low quality stands in poor-nutrient soil conditions