Silvicultural contributions towards sustainable management and conservation of forest genetic resources in Southern Ecuador.

Resumen

Forests with high tree species diversity (per area) are mostly characterized by a low abundance of the single species. This fact has strong implications on activities towards a sustainable management of forest genetic resources as well as towards their conservation. After selection of priority species using ecological and economical criteria, an assessment of the phenotypic and genetic variation within each priority species was started. For this purpose the phenology of Cedrela montana, Prumnopitys montana, Myrica pubescens, and Clethra revoluta was studied for a two-years period at two different sites: ECSF area (San Francisco valley) and El Bosque (close to San Pedro de Vilcabamba). In addition, forest inventories were carried out the dry forest La Ceiba and at ECSF area. The results show a high variation flowering dates and fructification intensity not only between the two geographical areas but also within. Consequently, this high variation must be considered management as well as conservation activities. The inventories showed that there are several species with subpopulations that may have no contact between each other or might be too small even for static conservation purposes. To delineate genecological zones (i.e. provenance regions), which can act as seed sources for sustainable forest management programmes as well as for the conservation of forest genetic variation, the existing maps of environmental conditions Loja and the vegetation cover were overlaid. After the identification of these zones and their size it can be decided if the areas will be sufficient for an in situ conservation and sustainable management or if additional measures have to be undertaken (e.g. establishment of seed orchards, clonal archives, amplification of conservation areas).