The Park's Natural History
The Plitvice lake system is divided into upper and lower sections. The upper lakes, lying in a dolomite valley, are surrounded by dense forests and are linked by several gushing waterfalls. The lower lakes are smaller and shallower. Most of the water comes from the Bijela and Crna (White and Black) Rivers, which join south of Prošćansko Lake, but the lakes are also fed by underground springs. In turn, water disappears into the porous limestone at some points, only to reemerge in other places. All the water empties into the Korana River near Sastavci Falls.
The upper lakes are separated by dolomite barriers, which expand with the mosses and algae that absorb calcium carbonate as river water rushes through the karst. The encrusted plants grow on top of each other, forming travertine barriers and creating waterfalls. The lower lakes were formed by cavities created by the water of the upper lakes. They undergo a similar process, as travertine is constantly forming and reforming itself into new combinations so that the landscape is ever changing. This unique interaction of water, rock and plant life has continued more or less undisturbed since the last ice age.
The lakes’ colours also change constantly. Most of the time they’re a surreal shade of turquoise, but hues shift with the quantity of minerals and organisms in the water, rainfall and the angle of sunlight. On some days the lakes can appear more jade green or steely grey.
The luxuriant vegetation of the national park includes beech, fir, spruce and white pine forests, dotted with patches of whitebeam, hornbeam and flowering ash, which change colour in autumn.
The mammalian stars of the park are bears (there are an estimated 50) and wolves, but there are also deer, boar, rabbits, foxes and badgers. Look out for bird species including hawks, owls, cuckoos, kingfishers, wild ducks and herons, and occasionally black storks and ospreys.