The geographical or geotectonics area of the Risnjak National Park belongs to the system of Dinaric mountains which represent the natural bond between the Alps and the Balkan mountains. It is a strong limestone area with very specific ecological, geomorfological and hydrological characteristics. The National Park has a complex structure of carbonate rocks whose formation date back to the Palaeozoic and to the Quaternary age. The oldest rocks from the Palaeozoic age are located in the upper flow of the Krašičevica and part of the Kupa River valley.
Rocks dating back to the Triassic period are located at the middle heights above sea level around Leska, Bela Vodica and Biljevina. Younger rocks from the Triassic and Jurassic periods are located on the higher areas of the Risnjak and Snježnik mountains.
The Risnjak and Snjeznik mountain massifs represent a natural connection between the Alps and the Dinaric mountains and due to this fact are considered an important ecological corridor for plants and for large animals, such as the brown bear or wolf.
The Risnjak National Park is influenced by Adriatic climate characteristics and the continental climate which interferes with each other within this area and determines its climate specificity. Pleasantly mild hot summers with an average temperature of 20°C are rotated with rainy autumns and springs and long, snowy and cold winters. In the higher areas the average temperatures decrease noticeably and the quantity of precipitations increase which is connected to the quantity of air humidity, the intensity of cloud cover, fog and other such phenomena. Cloud cover reaches a maximum level in November and December, and a minimum in July.
The whole area is characteristic for its typical limestone formed valleys and karst sinkholes and its special microclimate. They represent a separate living area with their own plant communities and typical temperature inversion which makes their environment completely different from that of their surroundings.
The Risnjak massif has always been known for its rich flora that has developed in various microclimatic and geological conditions. This diversity is the base for the relatively high level of floral variety. During field and other activities, and for the purpose of creating a Management plan, the spatial systematized inventory of flora has been carried out on the whole area of the Risnjak National Park.