Experimental analysis of dryland forest restoration techniques (Post-fire restoration of native tree species: effects of wood shaving application)

LALLEMENT M.E; TOGNETTI C; GOBBI M. E

Principles and Practice of Forest Landscape Restoration. Case studies from the drylands of Latin America

Newton A

Lugar: Gland; Año: 2011; p. 160 - 162

Fires are the most devastating anthropogenic disturbances in forests of the Andean-Patagonian region. They severely affect vegetation, fauna and surface soils, increasing the risk of erosion. Thus, it is extremely important to carry out tasks that aid in the ecological restoration of these ecosystems. The objective of this work was to study strategies that facilitate the recovery of burnt forest areas of NW Patagonia, specifically by means of reforestation with native woody species. In particular, tree planting carried out by volunteers and modifications of the substrate (both in a plant nursery and in the field) by addition of wood shavings were assessed. The study was carried out in a burnt area located in the Challhuaco Valley of the Nahuel Huapi National Park. Survival and growth of three native woody species (Austrocedrus chilensis, Nothofagus pumilio y Lomatia hirsuta) was evaluated, and the water dynamics in a substrate composed of soil + wood shavings (either mixed into, or covering the substrate as mulch). Growth and survival of plants in the reforestation carried out by volunteers was satisfactory; values obtained were within the range of those obtained in previous studies carried out under similar climatic conditions. Thus, this proved to be a good strategy to recover degraded areas, as well as an educational experience for the community. In plant-less assays i) mixing wood shavings into the soil increased water drainage velocity and field capacity, which would be an advantage to plants, as long as the water were available to roots; and ii) application of wood shavings as mulch delayed soil water evaporation. In plant nursery assays, for the three species studied, mixing wood shavings into the soil increased survival and improved some of the growth indicators. However, these parameters were not affected by the application of wood shavings as mulch. In the field studies, the use of wood shavings did not improve plant survival or growth, neither when mixed into the soil nor when applied as mulch. Nevertheless, mulched wood shavings did reduce and stabilize soil surface temperatures. This work is the first to consider L. hirsuta as a potential species for restoration projects, and it proved to have good survival and growth rates. The application of new strategies aimed at increasing plant survival and growth, especially those that use low cost and easily available resources, stimulates the development and undertaking of restoration projects. Ultimately, this accelerates the succession process in deteriorated natural habitats, and improves recovery of degraded areas