|QGIS and GRASS for modelling ecological corridors for wolves in North Portugal|
The Iberian wolf is a sub-species of the gray wolf that exists only in north of Portugal and Spain, with small isolated groups in the south of Douro river. During the last century, it suffered a high regression, being a “vulnerable” species in Spain and “endangered” in Portugal. Nowadays, there are only around 300 wolves in Portugal, due to the high persecution, destruction and fragmentation of the habitat.
Figure 1: Study area in Portugal.
Ribeira de Pena is a municipality in the Vila Real district in the north of Portugal. It is a rural municipality, characterized by agriculture, grazing livestock, forest, mountains, valleys and diverse fauna, along with low human density, that provides shelter and food for wolves. Located in a zone of transition between the harsh and mountainous Trás-os-Montes and the verdant Minho, Ribeira de Pena is one of the municipalities that can work like an ecological corridor between areas with higher wolf concentration in the north with lower concentration in the south.
With this work we obtained a map with the potential ecological corridors for wolf in Ribeira de Pena municipality. These are areas to be considered by the city council technicians when planning conservation measures for the species. These corridors are of extreme importance because they can connect the fragile wolf packs in Vila Real in the south with those in the north, which are continuous with those from Peneda-Gerês and Spain far more stable. It is from particular importance those corridors that cross human settlements, like small villages, cities and roads. These areas must be considered critical for wolf conservation, and applied measures to reduce human impact in this species.
Figure 2 and 3: Ecological corridors and critical conservation areas for wolves in northern Portugal.
Both QGIS and plugin GRASS are very intuitive with user-friendly interface, with all essential functions to perform most analysis. For what I could see, QGIS and GRASS perform equally as well as the proprietary programs I was most familiar with from college days, with the big advantage of free open-source software, usable in every computer or notebook without licenses, constant upgrades and the ultimate advantage to contribute to it's improvement and/or tip the developers about some essential function.
This article was contributed in July 2012 by Monica Almeida. She is conservation biologist working in an non-governmental organization in the preservation of wolf in Portugal.