Structure and Dynamics of Old-Growth Nothofagus Forests in the Valdivian Andes, Chile

Tree-fall gaps and patterns of tree recruitment and growth in Andean old-growth forests in south-central Chile

“…In this region, old-growth forests (> 300 year old) are dominated by the Coihue-Raulí-Tepa forest type (Donoso 1993), which is widespread between 600 and 1,000 m a.s.l. in the Andes of south-central Chile between 37-41°S, where either coihue (N. dombeyi), raulí (N. nervosa) or both, occupy emergent tiers, and the conifer mañío (S. conspicua), the hardwoods tepa (L. philippiana) and trevo (Dasyphyllum diacanthoides) occupy the main canopy tier (Veblen et al 1980(Veblen et al , 1981.…”

“…Large tracts of Andean montane forests (ca. 700-950 m a.s.l) are rarely found in a compositional equilibrium or climax condition (Veblen et al 1980, GlennLewin et al 1992. Andean montane forests are characterized by emergent trees such as Nothofagus dombeyi (Mirb.)…”

“…In canopy gaps, the bamboo Chusquea culeou E. Desv., considered a key species for its important influence on tree regeneration, forms thickets with culms at least six m tall (Veblen et al 1980(Veblen et al , 1981. In these mixed forests, the lack of saplings and small-diameter individuals of Nothofagus indicates that these shade-intolerant species can not establish in undisturbed old-growth stands (Veblen et al 1980, Veblen 1985a).…”

“…Desv., considered a key species for its important influence on tree regeneration, forms thickets with culms at least six m tall (Veblen et al 1980(Veblen et al , 1981. In these mixed forests, the lack of saplings and small-diameter individuals of Nothofagus indicates that these shade-intolerant species can not establish in undisturbed old-growth stands (Veblen et al 1980, Veblen 1985a). Both Nothofagus species are considered opportunist since they establish in large numbers and grow rapidly in open environments (catastrophic mode of regeneration, sensu Veblen 1992) created by large-scale natural disturbances such as landslides and volcanic ash falls, and also by fire and stand-devastating windthrow events (Veblen et al 1996).…”

“…Both Nothofagus species are considered opportunist since they establish in large numbers and grow rapidly in open environments (catastrophic mode of regeneration, sensu Veblen 1992) created by large-scale natural disturbances such as landslides and volcanic ash falls, and also by fire and stand-devastating windthrow events (Veblen et al 1996). In contrast, the two main shade-tolerant trees, L. philippiana and S. conspicua, show some life history traits (e.g., shade tolerance, vegetative reproduction) that allow them to persist and take dominance in the absence of massive disturbances (continuous and gapphase regeneration mode, sensu Veblen 1992, Veblen et al 1980, 1981, Veblen 1985a. Eventually, in these forests, the replacement of Nothofagus spp.…”