The total surface area of the Paklenica National Park is 95 km2. There are eight different forest communities in the overall area of the Park. The diversity of forest growth in this relatively small space was conditioned by a wide range of altitudes (20-1757m a.s.l.), geological differences, strong climatic effects and the presence of constant and occasional watercourses in certain areas of the Park.
On the highest peaks of the National Park, grows an impressive community of Mountain Pine and Honeysuckle (Lonicero-Pinetum mugi). This is the most compact and largest surface in Croatia covered in the Mountain Pine forest.
Descending from the highest peaks, a subalpine beech forest community is developed (Ranunculo platanifoliae-Fagetum). In some areas it grows as fully developed and with plant species typical for the community, and on steeper slopes, the trees grow bent due to the longer presence of snow and extremely steep slopes.
On acidic ground which results from the decomposition of old quartz clastic rocks a different kind of Beech forest has developed (Luzulo-Fagetum), whose herbaceous plant composition is dominated by Woodrush (Luzula sp.). They have no bushes – the ground is covered with a layer of moss, making it seem airy and ensuring moisture for the rich fauna in the ground.
Permanent and occasional watercourses in Paklenica have contributed to the development of a community of Common Beech and Deadnettle (Lamio orvale-Fagetum). This forest community stretches to the west of the mountain hut, along Brezimenjača creek and to the east of the mountain hut across Klimenta ridge. On the slopes where the influence of a slightly warmer climate prevails, the so-called climatogenic thermophilic beech forest with autumn sedge (Seslerio autumnalis-Fagetum) is developed. On the warmer and drier terrains of these localities, which are undesirable for beech growth, the community borders the black pine forests, and at higher altitudes, it usually passes directly into the subalpine beech forest.
Paklenica National Park owes its special status to the rare and endemic forest of Black Pine, which grows on skeletal and dry soil. The zone of Black Pine and Cotoneaster (Rockspray) forest community (Cotoneastro-Pinetum nigrae) stretches between the altitudes of 700 to 1200 m a.s.l. Black Pine (Pinus nigra L.) prefers somewhat more acidic ground than the limestone that is prevalent in most of the Park has to offer, so the most beautiful Black Pine forests can be found on dolomite ground.
The low-growth layer of vegetation that almost regularly accompanies Black Pine comprises Winter Heath (Erica herbacea), which blooms early in March, so Black Pine forest becomes especially attractive in late winter and early spring.
At lower altitudes, on limestone ground, there are two forest communities: Querco-Carpinetum orientalis and Aristolochio luteae-Quercetum pubescentis.
The forests of Paklenica National Park have provided habitats for numerous animal species, from the tiniest ants (Formicidae), of which there are 42 species in the Park, to large mammals such as bears (Ursus arctos), deer (Cervus elaphus), roe deer (Capreolus capreolus), wolves (Canis lupus), somewhat smaller martens (Martes martes and Martes foina), least weasels (Mustela nivalis), European badgers (Meles meles), red foxes (Vulpes vulpes) and wild boars (Sus scrofa). It is easy to spot traces of wild boars which dig up the ground when foraging for bulbs and roots.
