Tree carbon stock in evergreen forests of Chiloé, Chile

Abstract

The carbon stock associated with tree biomass was estimated in evergreen forests near the town of Inío in Chiloé Island, Chile (43°21' S, 74°07' W), analyzing its relation with biotic and abiotic properties. A total of 14 sampling plots of 20x50 m were located at variable distances from Inío and different elevations, slopes and aspects. At each plot, tree density, incident solar radiation, and spectral vegetation indices were quantified based on LANDSAT satellite data. Total tree carbon stock was estimated for each tree species and in total, using known allometric biomass functions based on the diameter at breast height (DBH), of all the trees in the plot with DBH> 3 cm. Four plots presented post-fire conditions, where tree carbon content had a mean (± SE) 7.7 ± 0.78 Mg ha^-1, while in the unburned plots it was 384.4 ± 120 Mg ha^-1. After removing the value of one plot with high carbon content, the average was 189.7 ± 45.6 Mg ha^-1. Most of the sampled properties had a limited correlation with tree carbon content (R² 0.31-0.69). However, the amount of carbon of Nothofagus nitida was related to the total tree carbon in all the plots (post-fire and unburned) with R² = 0.96. This model substantially simplifies sampling efforts, since only DBH data of N. nitida is needed for the analyses (average of 15 individuals per plot). The tree carbon stock of forests of this area is high when compared to other forest types of the world.