Abstract: Landscape connectivity is a key aspect for the maintenance of biodiversity and ecosystem viability.Nowadays, the competition between economic development and nature conservation is intense. In mostterritories natural vegetation is being replaced by exotic tree plantations, which have a better perfor-mance in terms of timber productivity but often, a lower ecological value. We evaluated potential naturalforest connectivity improvement in the Cantabria region (Northern Spain) through two main actions:protection of environmentally valuable forest areas, and reforestation with indigenous species of thosepatches of exotic plantation trees with a particularly important role for the connectivity of the forestnetwork. We established a variety of scenarios to calculate least cost paths, considering the presenceor absence of plantation forestry and highways to examine connectivity. Then, we applied two habitatavailability indices (integral index of connectivity and probability of connectivity) attending to differ-ent dispersal distances. Our analyses show a great potential for improving connectivity using plantationforests in the natural forest network, and a dramatic impact of the highway in the north–south con-nectivity of the study area. Based on these results, we identified those patches of plantation forest andnatural forest that are more important for the maintenance of overall landscape connectivity, and proposetheir protection or conversion through reforestation. The final proposed network constitutes a larger andbetter connected natural forested landscape than the existing one.