Establishment and Competition of Native Forest Species in Araucaria angustifolia Stands with Different Coverage Degrees in Misiones, Argentina

PINAZO, MARTÍN A; GRACIANO, CORINA; OLGUIN, FLAVIA Y.; GORTARI, FERMÍN; MORETTI, ANA PAULA; GAUNA, JUAN MARCELO

Basel (On line)

Conferencia; The 1st International Electronic Conference on Forests ? Forests for a Better Future: Sustainability, Innovation, Interdisciplinarity; 2020

Forests

Mixed plantations with native species are a viable tool to meet current wood production and conservation demands and can contribute to the restoration of degradedforests. In Misiones, Argentina, 30,000 ha of land are used for mono-specific plantationsof the native Araucaria angustifolia (Bertol.) Kuntze for timber purposes. Mixtures withother native timber species in uneven-aged plantations have ecological advantages overmonospecific stands because they have increased biodiversity and complexity. In mixedplantations, competition depends on the availability of resources, but also on the requirements and ages of the trees. Trees of different ages in A. angustifolia plantationshave different coverage intensities, environmental conditions, and understory structures, and can be used to protect the seedlings of coverage-demanding species duringtheir establishment. Six A. angustifolia stands of different ages, from 2 y (1200 trees/ha) to25 y (220 trees/ha), were enriched with native forest species. In each stand, one 100 m2plot for each species was installed. Fifty seedlings of Cabralea canjerana, Peltoforum dubium, Bastardiopsis densiflora, or Cordia trichotoma were planted per plot within the plantingrows. One year after planting, the survival was higher than 70% in all the species andmortality was not associated with the age of the stand. Survival was not affected byfrost, although the plants have been classified as frost-susceptible. However, growthwas lower in the stand where lower temperatures in winter were recorded. In the olderstand, competition did not affect the survival and growth of the species with a higherphenotypic plasticity, while it affected the growth of those that had a lower plasticity.The results suggest that it is possible to enrich mono-specific stands of different ageswith native timber trees. Therefore, mixed plantations of A.angustifolia with other nativespecies can be considered for wood production and conservation purposes in their naturalarea of distribution, as they increase the connectivity between the remaining rainforest.