Aspectos cinéticos da degradação de laminados de madeiras em ambientes aquático e terrestre

Decomposition rates of several wood especies was evaluated under aquatic and terrestrial environment in the Atlantic forest. Wood samples from five species were placed to decompose on the forest floor and twelve of them submerged in a lake, using the litter bags approach to evaluate directly the monthly progressive weight loss. Under lake conditions the decomposition presented tipical a initial period with faster weight loss due to leaching. Correlation analysis showed that wood color is inversely related with decomposition rates of angiosperms (r = - 0,95), but wood density is not a good predectivy variable. Decomposition was faster in the aquatic environment, as shown by coefficient K (Olson, 1963) verified for Torresea cearensis 0,63; Cordia goeldiana 0,61; Myroscarpus sp. 0,46; Cedrela sp. 0,35; Swietenia macrophyla 0,31; Araucaria angustifolia 0,28; Pinus sp. 0,26; Phoebe porosa 0,22; Machaerium villosum 0,22; Dalbergia nigra 0,21; Peltogyne discolor 0,20; and Ocotea sp. 0,19. The forest floor values was the following: Torresea cearensis 0,48; Cordia goeldiana 0,43; Phoebe porosa 0,20; Cedrela sp. 0,20; and Pinus 0,16.