Above-ground biomass accumulation and growth in a marginal Nothofagus macrocarpa forest in Central Chile

Abstract

Nothofagus macrocarpa forests are situated in the northern limit
\nof Nothofagus genus distribution in South America. Data related
\nto their growth conditions are insufficient. Above-ground biomass
\naccumulation and growth were evaluated in a secondary
\nN. macrocarpa forest located in the northern limit of the species
\nnatural distribution. Nine plots were established, and 240
\nsprouts of different diameter classes were harvested. The age
\nand volume of each sprout were determined, and tree growth in
\nterms of diameter and height was also analyzed. Total aboveground
\nbiomass was measured in a subsample of 62 sprouts, according
\nto the components: stem, branches and foliage. The forest
\nhad an uneven-aged coppice structure, the mean age being
\n39 years. Average diameter growth rate was 0.23cm/year, height
\ngrowth rate was 32.3cm/year and the mean volume growth rate
\nwas 0.43m3·ha-1/year, which are lower than the values indicated
\nfor other species of the same genus. The accumulated above
\nground biomass reached 35.2ton·ha-1. The low values measured
\nare explained by the marginal condition of the forest as well as
\nits degradation status due to anthropogenic activity. This condition
\nrequires of setting measures that assure the survival and
\nthe recovery of this forest.