Effects of canopy cover and neighboring vegetation on the early development of planted Austrocedrus chilensis and Nothofagus dombeyi in north Patagonian degraded forests

Abstract

Austrocedrus chilensis and Nothofagus dombeyi, are endemic forest species of ecological and productive importance in the Andean-Patagonian region of Argentina. Both species grow in pure or mixed stands. In the last decades, several A. chilensis stands have been degraded by different disturbances that have compromised their natural regeneration. Plantation of seedlings of both species may be an alternative to help restore degraded A. chilensis stands. In this study we determined, in degraded A. chilensis stands grown in a xeric and a mesic site, the effects of canopy cover, the presence/absence of neighboring herbaceous vegetation and the interaction between these factors, on the performance (i.e. survival and growth) of planted N. dombeyi and A. chilensis seedlings, during three growing seasons. Results showed that in both xeric and mesic sites, survival and growth of either species were reduced when canopy cover was below 30%. Removal of neighboring vegetation improved survival of both species at the xeric site, and improved growth of both species at the mesic site. Canopy cover and removal of neighboring vegetation seem to interact by improving survival and growth of A. chilensis, while for N. dombeyi the effects of these factors, when present, are independent, both improving survival and growth. Austrocedrus chilensis has greater capacity than N. dombeyi to tolerate the high radiation and low soil moisture combination, so this species is more recommendable for planting at most exposed conditions (no canopy cover at xeric sites), but both species could be successfully used for restoring degraded A. chilensis stands.