Effects of aspect and type of competition on the early performance of Nothofagus dombeyi and Nothofagus nervosa in a mixed plantation

Abstract

In the Andes of Chile, two valuable Nothofagus tree species coexist (Nothofagus dombeyi (Mirb.) Oerst. and Nothofagus nervosa (Phil.) Krasser). They could provide an opportunity for mixed plantations because of their ecological differences. In a mixed plantation with a checkerboard design on a good site where the two species naturally coexist, we evaluated their performance according to aspect and type of competition. Nothofagus dombeyi had a greater survivorship (90% vs. 65%) and growth (twice in diameter and 20% greater in height). Forking was significantly lower in N. nervosa (23% vs. 70%). Aspect did not significantly affect the performance of N. dombeyi. The north aspect had a significant negative effect on survivorship of N. nervosa, but aspect did not significantly affect growth or forking of this species. The aspect -type of competition interaction was only significant for N. nervosa in diameter and marginally significant in height. The checkerboard design allowed for a clear separation of interspecific and intraspecific competition in this mixed plantation. Interspecific competition favored growth of N. nervosa on the north aspect (facilitation) and was detrimental to N. nervosa on the south aspect (competition). These results have a direct application when planting mixtures of species of complementary ecological characteristics that can increase the value of the plantation.Résumé : Deux espèces arborescentes précieuses du genre Nothofagus (Nothofagus dombeyi (Mirb.) Oerst. et Nothofagus nervosa (Phil.) Krasser) qui coexistent dans les Andes chiliennes pourraient fournir une occasion de plantations mixtes étant donné leurs différences écologiques. Dans une plantation mixte avec un dispositif en damier sur une station de bonne qualité où les deux espèces coexistent naturellement, nous avons évalué leur performance en fonction de l'exposition et du type de compétition. Nothofagus dombeyi avait le plus haut taux de survie (90 % vs 65 %) et de croissance (le double en diamètre et 20 % de plus en hauteur). Il y avait significativement moins de troncs fourchus chez N. nervosa (23 % vs 70 %). L'exposition n'avait pas d'effet significatif sur la performance de N. dombeyi. L'exposition au nord avait un effet négatif significatif sur la survie de N. nervosa mais n'avait pas d'effet significatif sur la croissance ou la production de fourches chez cette espèce. L'interaction entre l'exposition et le type de compétition était significative seulement chez N. nervosa dans le cas de la croissance en diamètre et marginalement significative dans le cas de la croissance en hauteur. Le dispositif en damier a permis de distinguer clairement la compétition interspécifique et intraspécifique dans cette plantation mixte. La compétition interspécifique favorisait la croissance de N. nervosa lorsque la plantation était exposée au nord (facilitation) et défavorisait N. nervosa lorsqu'elle était exposée au sud (compétition). Ces résultats ont une application directe pour la plantation de mé-langes d'espèces dont les caractéristique...

Light availability and soil compaction influence the growth of underplanted Nothofagus following partial shelterwood harvest and soil scarification

“…3). For example, N. dombeyi had a higher growth plasticity to resource limitation than N. alpina, as the latter is commonly found on sites of relatively higher quality (sensu Donoso et al 1999Donoso et al , 2011Donoso and Soto 2010), suggesting that species adapted to better sites are more sensitive to detrimental soil conditions (Donoso et al 2011;Soto et al 2014). The difference in plasticity is reflected in both parameters of the Michaelis-Menten model (Table 2).…”

Effect of scarification on soil change and establishment of and artificial forest regeneration under Nothofagus spp. in Southern Chile

“…Even if the volume of the plants is similar in both situations, they grow less vigorously in smaller gaps. Nothofagus nervosa is semi-tolerant to shade, being favoured by partial shade conditions instead of open areas (Veblen et al, 1981;Donoso et al, 2006). In this study, the best development occurs in large gaps, although its opening is around 50%, equivalent to partial shade conditions.…”

“…Eventhough the N. nervosa plantation presents a high survival after 11 months of being established, its growth is moderate compared to other sites. For the first year in Valdivia Province, there are growth records of 6.0 mm in diameter and 52 cm in height in the Central Valley and growht of 8.4 mm in diameter and 69 cm in height in the Coastal Range (Donoso et al, 1999); also height growht > 50 cm (Donoso et al, 2006), and height growht between 60 and 70 cm in the Valdivian Andes (650 m asl) (Donoso et al, 2009). Still, the sites in this study have a more restrictive climate, with plants remaining five to six months under the snow.…”

“…This large amount of biomass in the topsoil difficults the establishment of other species, so silvicultural interventions are needed to facilitate the establishment of regeneration. A study on natural regeneration of N. nervosa in Chile (Donoso et al, 2006) reported that scarification improved the survival of this species (more than double compared to the non-intervened area) and, if accompanied by a shelterwood cutting, its height was increased compared to other treatments.…”

Differential Early Performance of Two Underplanted Hardwood Tree Species Following Restoration Treatments in High-Graded Temperate Rainforests

“…In this study, we did not evaluate the growth under very open canopies (>60%). However, Donoso et al [65] and Soto et al [10,35] showed that greater growth rates in Raulí occur in open fields when planted with neighboring faster-growing evergreen species (i.e., facilitation mechanisms under partial shade). In addition, Donoso et al [9,45] showed that the growth in Raulí was indifferent to canopy openness during the seedling stages but during the sapling stages, growth was enhanced with increased light.…”