Impact of territorial constraints on the optimization of forest accessibility. GIS Spatial Analysis for Quercus forests in National Park of Peneda-Gerês, northwest Portugal

摘要

ArcGIS software was used for timber harvesting planning in four (4) different mountainous forest areas of Peneda-Gerês National Park (PNPG), located in Northwest Portugal. Orographic characteristics, such as slope and watershed systems features were considered. The different manual and mechanical timber extraction and concentration methods were also considered. The different typologies of roads network to access forests were also introduced in the models. The analysis allowed identifying forest areas with different accessibilities and orographic restrictions. Performed analysis also allowed the planning of additional roads necessary for timber extraction optimization, considering optimized site-by-site timber extraction methods. The proposal of accessibility improvement through new roads construction was also considered important for forest fire prevention and for fire direct combat. However, the present proposal of accessibility improvement is merely an academic exercise because nature conservation restrictions severely limit the construction of new forest roads. This methodological approach should be tested in other mountainous forest regions throughout Europe.