Ecological and anthropogenic drivers of Calabrian pine (Pinus nigra J.F. Arn. ssp. laricio (Poiret) Maire) distribution in the Sila mountain range.

The most well-known and vast Calabrian pine forests are in the Sila mountain range, southern Italy. In this paper, present-day distribution of Calabrian pine in the Sila district was analyzed and compared with forest maps dating back to 1935 in order to assess the changes in land use. Main ecological and anthropogenic factors affecting Calabrian pine forest distribution were investigated by logistic regression models to identify the most important predictors of Calabrian pine persistence, expansion, and transition over the period 1935-2006. In 2006, the area covered by Calabrian pine forests and mixed Calabrian pine-beech forests was 36 100 ha and 20 221 ha, respectively. Overall, pine forest area increased by 38% between 1935 and 2006. Logistic regression revealed that Calabrian pine distribution in the Sila district was affected by both ecological (bioclimate, soil, and elevation) and anthropogenic factors (management, fire). Based on our results, four different potential dynamics of Calabrian pine stands are discussed in the perspective of the sustainable management and conservation of this important mountain forest habitat.