Alternating Raised Bogs and Open Bogs  
Deceptively Beautiful Mire Vegetation 
Mire Birds
 

The Reposuo area is made up of two vast open bog areas, between which are the Reposaaret forested land islet as well as Lake Olpperinlampi. The mire is bordered on the Pankajärvi side by saplings and on the Ruunaantie road side by beautiful ridges.

Photo: Heikki Räsänen

Every Mire is Unique

Visitors who have hiked in mires know that no two mires are exactly alike. Reposuo is in the border zone between Northern Karelia's raised bogs and Ostrobothnia's open bogs and the area is therefore a mix of the two. The area's alternating bog types and diverse vegetation make the landscape interesting and visitors can observe it from the trail.

Bird Mire

After winter Reposuo awakes to a flurry of activity as migrating birds return from the south. At times Reposuo is filled with the cries of gulls as they defend their nests. As ospreys glide across the sky, the crane carefully moves down in the mire. Reposuo is a valuable nesting area and popular as a rest spot during migration time. The area offers ideal conditions for many different bird species.

Occassionally Seen Visitors in the Mires

The Bear (Ursus arctos), the Wolf (Canis lupus) and the Fox (Vulpes vulpes) all occassionally pass through the mires and even the Wild Forest Reindeer may show up there sometimes. Visitors may be able to spot these timid animals from the Nature observation tower. A few Flying Squirrels (Pteromys volans) live in the shelter of the area's forest. One of the only sign of their existence are their dropping at the foot of aspens.
 

Alternating Raised Bogs and Open Bogs

When observing the mires from the bird watching tower or higher ridges visitors will notice that they are lines which bring variety to the scenery. These lines which are present at even intervals are caused by alternating mire types existing side by side. Grooves in this pattern are caused by the slant of the mire and by frost combined.

A summery open bog. Photo: Metsähallitus

The area's flat aapa bogs are wetter and more nutrient rich than raised bogs there. For this reason aapa bogs have more diverse vegetation. The Rannoch-rush (Scheuchzeria palustris) is one of the most common plants in Reposuo. It thrives in watery places inbetween patches of Sphagnum moss. In midsummer Rannoch-rushes can be seen from far away as they shine a bright green. In autumn they turn the landscape a rusty brown.


The boundary between the area's raised bogs and aapa bogs is clearly seen. In between the two mire types there is a high and deep green sea of sedge. The meadows in the area were cut down to feed livestock up until the 1950s.

Sphagnum moss in the centre of rugged raised bogs sits higher than the edges of the bog. Raised bogs depend on nutrients transported to them by rainwater. For this reason the mire's turf is nutrient poor and the centres of raised bogs have little vegetation. In July the mire landscape is decorated by the white ears of White Beak-sedges (Rhynchospora alba).

In Reposuo's forest islets the mire is rugged pine bog covered by Rusty Peat Moss (Sphagnum fuscum), in which only dwarf pines grow. Plants which bring colour to spagnum moss include the Leatherleaf (Chamaedaphne calyculata), the Cranberry (Vaccinium oxycoccos), the Bog Rosemary (Andromeda polifolia) and the Round Sundew (Drosera rotundifolia). 

Deceptively Beautiful Mire Vegetation 

English Sundew (Drosera anglica). Photo: Markus SirkkaIn early summer hikers walking along Ketunlenkki Circle Trail are treated to scenery covered by a sea of pink flowers. The Bog Rosemary's (Andromeda polifolia) beauty however is deceptive. While the flower looks fragile it is actually a poisonous plant.

The mire's most extraordinary plants are the meat-eaters. These include the Round Leaf Sundew (Drosera rotundifolia) which grows on hummocks in pine bogs, the English Sundew (Drosera anglica) which thrives on watery flarks and the Bladderwort (Utricularia) which floats freely in water.

Bladderworts and sun dews derive nitrogen nutrients from their insect diet. These nutrients are not present in the soil in the growth area. Sun dews catch insects with their red hairs, which excrete a sticky substance. The baldderwort has a catch trap within which there is a vaccuum. When for example a Daphnia (Daphnia magna) lightly brushes by the plant's sensitive hairs the trap opens inward and the water pressure sucks the prey inside.

Mire Birds 

The most visible and audible part of Reposuo's bird population are the gulls. The Common Black-headed Gull (Larus ridibundus), the Little Gull (Larus minutus) and the Common Tern (Sterna hirundo) nest in large communities which on occassion rise in a cloud into the sky to ward off unwanted visitors such as the Carrion Crow (Corvus corone). Further off in the centre of the open bogs the Mew Gull (Larus canus) and the Herring Gull (Larus argentatus) thrive while living separated from other gulls.

Waders which nest side by side in the calm open bogs include the Eurasian Curlew (Numenius arquata), the Whimbrel (Numenius phaeopus), the Wood Sandpiper (Tringa glareola), the Eurasian Golden Plover (Pluvialis apricaria) and the Common Greenshank (Tringa nebularia). The Spotted Redshank (Tringa erythropus) also occassionally visits Reposuo. The wader that garners the most attention is the male Ruff (Philomachus pugnax) with its impressive feather collar. The Common Snipe (Gallinago gallinago) hides in the vicinity of ponds.

Waterbirds which thrive in ponds in the area's raised bogs include the Common Teal (Anas crecca), the Eurasian Wigeon (Anas penelope) and the Northern Pintail (Anas acuta) as well as the Mallard (Anas platyrhynchos). Even the Garganey (Anas querquedula), which is a demanding specie, nests at Reposuo.

Two mating Swan (Cygnus cygnus) couples share Reposuo as their territory. Each pair vehemently defends its own half of the mire. The timid Black-throated Diver (Gavia arctica) and Cranes (Grus grus) on the other hand nest along the area's shoreline. The Black-throated Diver is usually found in the Lake Pankajärvi area while the Crane wanders into the sheltered areas of the mire.

Nesting Birds of Prey

From the bird watching tower visitors can observe for example the Osprey (Pandion haliaetus) gliding across the sky. As well as ospreys the Merlin (Falco columbarius) and the Eurasian Hobby (Falco subbuteo) hunt in Reposuo Mire. These birds will cry out loudly in warning if hikers wander too near their nests.

Many Tetraonids

On spring mornings the lively chatter of the Black Grouse (Tetrao tetrix) can be heard from the open bog. Hikers wandering in the mires and forests can be startled by the Western Capercaillie (Tetrao urogallus) suddenly taking flight or the loud cackling of the Willow Grouse (Lagopus lagopus). In the forest islets visitors may come across small sandy depressions where tetraonids bathe. The Hazel Grouse (Bonasa bonasia) is another tetraonid that nests in the area.

Forest Songbirds

Thrushes (Turdidae) sing their song in the area's forest islets while Rustic Buntings (Emberiza rustica) hold their concert in spruce mires. The Willow Warbler (Phylloscopus trochilus), the Chaffinch (Fringilla coelebs) and the Tree Pipit (Anthus trivialis) live in young forests. The pines forest bordering the mires are home to the bubbly voiced Lesser Whitethroat (Sylvia curruca).