Trnovo Forest Plateau
The Trnovo Forest Plateau is a karst plateau that constitutes the extreme northwest end of the Dinaric Alps. The Trnovo Forest Plateau has a karst character, without surface watercourses and broken up by closed valleys, outcroppings, hills, caves, shafts, and smaller karst features: solution pans, rills, karrens, and other features. Significant karst features include ice caves. The vegetation inversion at Big Paradana Ice Cave in the eastern part of the plateau, measuring by, is a locus classicus and in the past ice was harvested from it and exported via Gorizia and Trieste to Egypt.
The Trnovo Forest Plateau has three nature reserves:
- Big Paradana Ice Cave
- Golak Peaks and Spruce Valley
- The Smrečje forest reserve
Terrain
The influence of tectonic activity is very evident in the area. There are many depressions, solution valleys, small karst poljes, and the remains of former river valleys. During the Pliocene the rivers leveled the tectonic upwelling and filled the valleys. Traces were also left by Pliocene glaciation because glaciers created small cirques on what had been a relatively level surface, as well as ground moraines and terminal moraines. The rivers transported gravel and deposited it in lower areas, filling the depressions.Rock
The north side of the plateau shows tectonic formation along the Idrija Fault oriented in the Dinaric direction, and the south side shows the results of tectonic thrusting of Mesozoic limestone and dolomite over younger Eocene flysch. Two-thirds of the surface is covered by limestone, one-fourth by dolomite, and the remainder is flysch and loose material.Mountains
The highest summit is Big Mount Golak. On the northern side, some other panoramic and frequently visited summits are Little Mount Golak, Mount Poldanovec, and Pointed Peak, and on the southern side Big Mount Modrasovec, Mount Kucelj, Blue Peak, and Kovk Hill.Natural landmarks
- Skozno natural rock window
- Otlica natural rock window
- Hubelj karst spring
- Vipava springs
- Lijak karst spring
- Wild Lake
- Paradana Cave
Climate
The climate of the Trnovo Forest Plateau is defined by its elevation and orientation. The Trnovo Forest Plateau lies in a continental temperature zone. It receives an average of of precipitation per year. Differences in the quantity of precipitation differ little on a monthly basis. The greatest precipitation is in November and the least in February. The majority of winter precipitation is in the form of snow, especially at higher elevations. The bora wind is a typical weather phenomenon, blowing down from the plateau towards the sea with gusts often exceeding. The bora can cause considerable damage in the area, uprooting trees and tearing the roofs off of houses.Water
Despite the abundant precipitation, karst plateaus have almost no water. The drainage divide is unclear because of the karst surface. The largest spring is that of the Hubelj River near Ajdovščina.Vegetation
The Trnovo Forest Plateau is covered by mixed beech and fir forest. The highest vegetation is on Little Mount Golak, which is bare at the summit, below which grow dwarf willow and mountain pine. Protected flora grows in the rocky crevices, including the Carniolan primrose.The share of forest is 75.5%, but this is increasing because of the afforestation of abandoned farmland. Poor accessibility has resulted in relatively good preservation of the landscape features. The highest peaks are overgrown with mountain pine or grass. Dinaric beech and fir forest grow at elevations between and. At lower elevations this transitions into Dinaric submontane beech forest. There is relatively little shrubland.