Distribution and habitat conditions of Pinus cembra forests in the Tatra Mountains

Relic Pinus cembra forests were among the least studied plant communities in the Western Car- pathians. Their distribution in this mountain range is limited only to the Tatras. The lack of comprehensive research on the Polish and Slovakian sides of the Tatras led to considerable discrepancy regarding their distribution (300–1170 ha) as well as habitat conditions. Their occurrence on limestones and in the West- ern Tatras was contested. Therefore, the aim of this work was to determine the distribution and habitat conditions for the occurrence of Swiss stone pine forests in the Tatras. We mapped the entire range of the distribution of these forests, using the topographic method and digitized it in ArcGIS 10.2.2. Afterwards, we undertook spatial analysis, using DEM regarding their occurrence, depending on: altitude, inclination, solar radiation, exposure, geology and soil. To determine the preferable site conditions we used the logistic regression model. The total area of P. cembra forests in the Tatras is 916.93 ha. They occur in all mountain ranges within the Tatras. Altitude, inclination and solar radiation have significant impacts on the occur- rence of these forests. The odds of the occurrence of P. cembra forests increased by 0.5% for every 1 m of altitude, by 2% for every 1° of inclination and decrease by 0.1% for every 1 MJ/m2/year of solar radiation. The majority of these forests grow in the altitude range 1300–1650 m a.s.l. (95%) and on slopes with 20–60° inclinations (80%). Swiss stone pine forests occur both on slopes with low (1900 MJ/m2) and high annual solar radiation (3400 MJ/m2). They prefer slopes with North-western exposure. They may grow both on granite and limestone, while the majority of them were mapped on granite. Pinus cembra forests grow on diverse soils, both acidic and alkaline. Nevertheless, most of them occur on Haplic Podzols (52%). The results may be applicable to the Tatra National Park for the conservation and monitoring of this Natura 2000 habitat.