Estimation and spatial analysis of aerial biomass and carbon capture in native forests in the south of Chile: county of Valdivia

Abstract

Introduction: Native forest reserves in southern Chile are the largest carbon sinks in the country, but the amount and level of grouping of the polygons that form these coverages is unknown.Objective: to estimate aerial biomass (AB) and carbon content in native forests in the county of Valdivia, Los Rios region, as well as the degree of grouping of polygons containing carbon in aerial biomass. Materials and methods: 21 land plots of 50 x 10 m were installed. Tree species were identified, and their diameter and height were measured. The AB was calculated using allometric equations, and the carbon content was calculated relating the AB to the factor 0.5. The degree of grouping of polygons with carbon content was calculated using the Getis-Ord G statistic.Results and discussion: The total carbon content in AB was estimated at 599.6 Mg C·ha-1. Carbon is concentrated in three forest types, Evergreen being the most important (63.3 %). The most abundant species was Nothofagus obliqua (Mirb.) Oerst. (18.34 %). There is a clustered spatial dependence on carbon-containing polygons in areas with forest reserves; the rest of the territory showed random distribution. Spatial dependence is related to the physiographic characteristics of the study area.Conclusions: The use of allometric functions for the estimation of aerial biomass and factors to obtain the carbon content is a valid methodology. The carbon polygons of the native forests in Valdivia have grouped spatial distribution.