Since it is winter and exam season is closing in, I am not spending a lot of time in the lab (or anywhere interesting). Because of that, I wanted to write a short throwback post about last time I visited one Croatian National Park. Despite being a very small country, Croatia is rich in intact nature and preserved areas. The most famous of those areas are National Parks, and Croatia has eight! I also must mention, that in spite of popular belief, there are two areas more protected than National Parks – “strict reserves.”

The National Park I’ve paid a visit more than a year ago (November 2017) is called Plitvice Lakes, or simply Plitvice. The area is a National Park since 1949 and it’s Croatia’s biggest and oldest Park. It consists of 16 lakes that are connected by many waterfalls and cascades. The specificity of the Park is tufa – yes, I checked, that’s the word! 🙂 Tufa is a calcareous rock (meaning it is mostly made of calcium carbonate) and is porous. It is generated by precipitation of carbonate minerals out of water, and generally this type of rock is very sensitive to changes in pH. Why is it so special? Tufa forms barriers between the lakes! Those barriers are the reason why Plitvice are also part of the UNESCO World Heritage List.

Picture 1. A famous view on Plitvice Lakes

Picture 2. Amazing waterfall in Plitvice

For the Chemistry lovers, here is a chemical formula of tufa formation:

Ca²⁺ +2HCO₃^–  ↔CO₂ + H₂O + CaCO₃

Apart from environmental factors, small organisms play very important role in the formation as well. There are bacteria, small multi-cellular organisms, blue-green algae (not algae at all) and diatoms (actual algae). Mosses are part of this ecosystem as well, together with many other smaller organisms, both animals and plants.

As I already mentioned, there are several factors important for the formation of tufa rocks, and pH of the water is the one you have probably heard about. The reason why is it almost exclusively mentioned is pollution that changes pH of the lakes. One of the main problems? Tourism. Yes, tourism. I won’t get in the detail about not-so-well-made sewer system in the whole area, but Plitvice are one of the most famous places in Croatia, and as such, receptible to huge numbers of visitors every summer. And sometimes, that people don’t follow basic rules of spending their time in nature, so a lot of littering and wild-life disturbance occurs. Don’t get me wrong, this National Park is open to the public and meant to be enjoyed, but sometimes it seems more emphasis is put on money, rather on educations. Because of that, I would sincerely like to ask all of you, to take care of our environment, especially when visiting a foreign country.

Picture 3. Calm lake and some rocks. And trees.

Picture 4.  View of a lake, before the boat drive

Anyway, back to my excursion! I was part of the group from my Department, as a part of the field trip for subject “National Parks.” It was a one-day trip, and we walked approximately 10 km around the lakes. The biggest lake is called Kozjak, and it is also a deepest lake. All lakes are beautiful blue-green colour and surrounded with walking paths and breath-taking views. The weather was a bit cold-ish, since it was November, but enough to walk around in a jacket and winter hat. And a camera of course! I tried to picture most of the nature and wildlife around me, but we didn’t see as much (again, because it was almost winter). However, Plitvice are rich in both flora and fauna – its symbol is a brown bear! Grey wolves and lynxes are also natural to the habitat, as well as many bird species – I’ve seen robins (Erithacus rubecula), some sparrows (Passer domesticus), and mallards (Anas platyrhynchos), but falcons (Falco peregrinus) and pygmy owls (Glaucidium passerinum) are regularly sighted. From other flying creatures, the Parks is full of butterflies (Phengaris alcon), bees (Apis mellifera), and similar (Calopteryx virgo), as well as bats (Barbastella barbastellus; there are also many caves in the Park!). There are many salamanders (Salamandra atra), otters (Lutra lutra; that I very sadly haven’t spotted), and fish. A lot of fish. I would also like to mention, that an endemic species was found in this area, in one of the caves – a small bug, Machaerites udrzali, which belongs in order Coleoptera. Forest(s) around the Lakes are full of common beech (Fagus sylvatica), but there are also firs (Abies alba), pines (Pinus sylvestris), and Ostryas. In fact, when it comes to flora, there are more than one thousand registered plant species, including dead-nettles and orchids. Mushrooms also have an important presence in Croatian forests, and Plitvice forest is famous for being a home to another rare species – saprophytic fungi Camarops tubulina.

Picture 5. Mallards humbly asking for bread

So, what do you think? Did you know that this National Park is so full of life? Because I honestly didn’t, despite living in Croatia, well, my whole life. Of course, we were taught about some general facts during our schooling, but I was really surprised to learn how many different species live here.
Apart from such an important biological aspect, Plitvice Lakes are important in Croatian history as well, but I might talk about that next time!

Did you visit Plitvice, what were your experiences? How about some other Croatian National Park? Which one should I visit&write about next? 🙂

P.s. Yes, the header picture of my blog was also taken during this trip!