Characterization and decomposition of Nothofagus pumilio fine woody debris

MORETTO A; GALLO AL; GRESLEBIN AG; LÓPEZ BERNAL P

CANADIAN JOURNAL OF FOREST RESEARCH

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2019 vol. 49 p. 715 - 720

0045-5067

Wood is one of the main carbon and nutrient reservoirs in Nothofagus pumilio forests; hence its decomposition is essential for carbon and nutrients cycling. Chemical traits are one of the factors affecting wood decomposition, but there is little information describing these chemical characteristics. Our objective was to analyze N. pumilio fine woody material (FWM) chemical traits and their relationship with decomposition. We determined the content of nitrogen, phosphorus, carbon, hemicellulose, cellulose, lignin and extractives in two diameter categories (branches and twigs) and in two decay classes (DC1: sound wood; DC2: intermediate stage of decomposition). We also determined the decomposition rate-constant (k) of each type of material. Content of P, extractives, carbon and hemicellulose in DC1, and carbon, cellulose and lignin in DC2 showed differences between diameters. Regarding DC, in twigs all chemical traits and in branches only N and carbon showed differences between DC. Mean k was similar between diameters and greater in DC2 than in DC1. Hemicellulose and P showed positive relations with increasing decomposition, while cellulose showed a negative one. Our results support the use of classical decay classes. We hypothesize that the presence/absence and proportional amount of bark partially explains the differences found between DC and between diameters.