Characterization and decomposition of Nothofagus pumilio woody debris

GALLO, A.L.; MORETTO, A.; LÓPEZ BERNAL, P.; GRESLEBIN, A.G.

CANADIAN JOURNAL OF FOREST RESEARCH

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2018

0045-5067

Wood is one of the main carbon and nutrient reservoirs in Nothofagus pumilio forests; hence its decomposition is essential for forest survival. Chemical traits are one of the factors affecting wood decomposition, but it is a poorly studied aspect of these forests. The objective of our study was to analyze N. pumilio fine woody debris (FWD) chemical traits and their relation with decomposition. We determined the content of nitrogen, phosphorus, carbon, hemicellulose, cellulose, lignin and extractive 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 debris. In DC1, P, extractives, carbon and hemicellulose content showed differences between twigs and branches; in DC2, carbon, cellulose and lignin did. Regarding DC, in twigs all chemical traits showed differences between DC, while in branches only N and carbon did. Mean k was similar between diameters and greater in DC2 than in DC1. Hemicellulose and P showed positive relations with decomposition, while cellulose and lignin showed negative ones. Our results support classical decay classes, thus strengthening the use of these categories. We hypothesize that bark partially explains the differences found between diameters and between DC.