Leaf area-sapwood area of Austrocedrus chilensis and Nothofagus dombeyi for the analysis of the growth of mixed forests.

CASELLI MARINA; LOGUERCIO G.; URRETAVIZCAYA M. F.; DEFOSSÉ G.E.

Valdivia

Workshop; XI International Workshop on 11th Uneven-aged silviculture: Challenges for increasing adaptability; 2018

UACh - IUFRO

There is a growing interest in management of mixed forests,due to their productive strengths and their greater ability to adapt tochanges, in comparison with monospecific ones. The silviculture of Austrocedruschilensis, an endemic conifer of Andean forests, limited by a disease that causeslosses in growth and mortality. Improvement of light conditions due disease triggersnatural regeneration of A. chilensis and when there is a nearby seed source,also that Nothofagus dombeyi, a hardwood with which A. chilensis combines inpart of its natural distribution. The incorporation of N. dombeyi appears aspossibility of adaptive management for the conduction of the affected forestsas mixed forests. For silviculture decisions to manage these forests we proposethe use of growth models through the distribution of leaf area between species andheight strata. Results development of leaf area-sapwood area models A. chilensisand N. dombeyi and its first applications study distribution of growth in severalstructures natural mixed stands are shown. Both species show high correlation (R2>0.91)between volume growth and leaf area index (LAI). The efficiency of occupationof the growing space (growth/LAI) in N. dombeyi is two to three times that ofA. chilensis in both height strata in all the structures studied. Preliminaryresults show that in mixed forest with a LAI range of 5-8, stand volume growth variationsare independent of A. chilensis LAI and they only depends on N. dombeyi LAI. Standvolume growth was 5.2 m3/ha/yr when N. dombeyi LAI was 2, and 8.7 m3/ha/yr whenN. dombeyi LAI was 5, with a quadratic relation between these variables. These resultsindicate that the incorporation of N. dombeyi in the structure would greatly increasethe productivity of the pure A. chilensis stands, making these forests much moreattractive economically and helping to avoid losses of forest areas.