Helvetinkolu - the National Park’s regional emblem
The special features of the park include two rift valleys, which have been formed 150-200 million years ago by displacement of the earths crust. Helvetinkolu Gorge, located northeast of the Lake Iso Helvetinjärvi, is the most famous gorge in the area. It is narrow, only a couple of metres wide cleft, which descends steeply to the lake side.
Lakes Kovero, Luomajärvi, Iso Helvetinjärvi, Pikku Helvetinjärvi and Pitkä Helvetinjärvi form a narrow steeply sided chain in the deepest fault, north of Helvetinkolu Gorge. At their highest points the fault-line scarps reach a height of 180-210 metres above the sea level. At some places the sheer cliff faces of the lakeshores rise up to tens of metres from the lake water level.
The vegetation on the cliffs of Helvetinjärvi is lush and diverse. The most spectacular sights are on the north side of Helvetinkolu in the area around the lake that has formed there. The tops of cliffs, steep slopes, rock shelves, crevices, the bottoms of rock walls and cavities each have their own characteristic type of vegetation. As well as the type of surface they grow on vegetation is effected by the direction in which it faces, sunlight and shade, how it is sheltered by cliffs, the type of rock it is growing on and how much run-off water the growth spot gets. For these reasons one cliff-side is not likely to have one uniform type of vegetation but different plant colonies right next to each other. By this reasoning the number of species in the area could be larger, but the cliffs are rugged and have few nutrients, which makes it impossible for more demanding species to survive there.
Reindeer lichen and shrubbery typically cover the tops of cliffs. The smaller types of reindeer lichen Cladonia rangiferina and Cladonia arbuscula are more dominant that the larger sized Cladonia stellaris, but there is also room for the Blueberry and the Ligonberry and some mosses such of the Dicranum and the Red-stemmed Feather-moss. The grainy and prickly surface of lichen rugs are interesting to observe, but at the same time visitors should respect that it is fragile and the surface should not be disturbed.
Other species are dominant on steep cliff faces. Skull Lichen and crustose lichens thrive on sunny rock walls. Even dry spells which last several months will not damage skull lichen as it is effective at storing up water from the dew that gathers on it in the morning hours. The lichens do not however dominate the rock faces alone as the Black Rock Moss for example grows along the cliff walls. Paraleucobryum longifolium and other mosses grow on the shady side of the cliffs in the shelter of spruce forests, where there are few if any lichen.
Predominantly on the cliffs which are shaded there is also a phenomenon of "dripping moss", which means moss grows down the side of rock walls in a slithering way. It can then detach itself from the surface in large patches. Types of moss which may grow this way are feather moss, dicranum and spaghnum moss. The most common moss in cliff crevices is the deliciously named Apple Moss.
Forests in their natural state
In the National Park there are still parts of the old backwoods in their natural state. Gorges and small forest ponds fringed with old-growth forest have the oldest tree stand. The trunks of the area's trees are embroidered with Lungwort (Lobaria pulmonaria), which benefit from the humid microclimate of old-growth forests. The presence of lungworts is a sign that a forest in its natural state. Hanging mosses (Usnea spp.) and lichens (Bryoria spp. and Alcetoria pss.) sway in wind from tree branches and shelf fungi bulge from tree trunks.
The old-growth forest can be seen for example on the hiking trail between Helvetinkolu Gorge and Lake Luomajärvi.
Helvetinjärvi National Park is in the boundary between vegetation zones, which means that northern and southern species alike can be found in the area. The Rusty Woodsia (Woodsia ilvensis), the Maiden Hair Spleenwort (Asplenium trichomanes), the Northern Spleenwort (Asplenium septentrionale), the German Catchfly (Lychnis viscaria),the Morrison's Spurrey (Spergula morisonii) and the Wood Bluegrass represent southern species, while the Alpine Catchfly (Lychnis alpina)and the Meadow-grass (Poa glauca) are northern species which grow in the area. As the soil in the area is rugged and does not have many nutrients the dominant species are non-demanding forest and mire vegetation.
In the area surrounding the gorge the quality of the earth is somewhat better and it is in these areas that most diverse herb-rich forest vegetation is found. The Baneberry (Actaea spicata), the Meadow Horsetail (Equisetum pratense), Fragrant Bedstraw (Galium triflorum),the Green Spleenwort (Coeloglossum viride), the Glyceria lithuanica, the Common Hepatica (Hepatica nobilis), the Ostrich Fern (Matteuccia struthiopteris), the European Bird Cherry (Prunus padus),the Alpine Currant (Ribes alpinum), the Small-leaved Linden (Tilia cordata) and the European Cranberrybush (Viburnum opulus) make the area lush.
The aim of Helvetinjärvi National Park is also to conserve rare species. Numerous regionally endangered and nationally threatened moss, lichen and shelf fungi species are found in the area.
The Eurasian three-toed woodpecker - our spring-time drummer
The restricted area has been established to protect the nesting birds. The breeding species of Lake Haukkajärvi include the Black-throated Diver (Gavia arctica) and the Lesser Black-backed Gull (Larus fuscus) , which are very sensitive to disturbances during the nesting period.
The Lesser Black-backed Gull is a slender gull with yellow legs and it has became rare in the last years. The Lesser Black-backed Gull starts nesting late in the summer, when people are on holidays, so it suffers from disturbances caused by for example boating.
The Lesser Black-backed Gull is the most Finnish bird in the world: the Finnish ones belong to subspecies fuscus which only lives in Fennoscandia. Our responsibility in protecting these birds is therefore great.
Several shelf fungi species which are typical of old-growth forests have been found in the Helvetinjärvi area. Some of these species are Phellinus chrysoloma, Phellinus ferrugineofuscus, Phellinus lundellii, Phellinus viticola and Fomitopsis rosea. Other species living in the old-growth forest include the Siberian Flying Squirrel (Pteromys volans), Three-toed Woodpecker (Picoides tridactylus) and Red-breasted Flycatcher (Ficedula parva).