Sipoonkorpi Nature Reserve is located within the municipalities of Sipoo, Vantaa and Helsinki. It is one of the most significant forest areas with no buildings near the Helsinki metropolitan area, the other one being the Nuuksio lake highland. Sipoonkorpi plays an extremely important role in the conservation of biodiversity in forests. It is a Natura 2000 site (www.ymparisto.fi, in Finnish).
Sipoonkorpi is made up of many different forest types, mires and cultural landscapes. There are only a few lakes in the area. The terrain is diverse and at some points there are large changes in altitude. There are many open cliffs. There are also many spruce mires and small bogs. With all these Sipoonkorpi can be characterised as having diverse and small natural features.
Many of the forests in Sipoonkorpi are spruce dominated. There are many lush and herb-rich forests as well as rocky forests. Some of the area's forests are valuable old forests which are practically in their natural state. These provide a home for species that are dependant on rotting wood. The area's flora and fauna is indeed diverse and abundant and includes endangered as well as rare plant, mushroom and animal species. Plants such as the rare Dog's Mercury (Mercurialis perennis), Anemone ranunculoide and the Fumewort (Corydalis solida ) grow in the area's herb-rich forests. In addition almost all of Southern Finland's forest mammal and bird species can be found at Sipoonkorpi. It is one of the last regions near the Helsinki metropolitan area that offers a habitat for species, such as the western capercaillie (Tetrao urogallus), that require large wilderness-like forest areas.
The landscape in Byabäcken River Valley alternates between farmed hillsides and forested hilltops and cliff areas. The river that flows through the centre of the valley is surrounded by fields and heritage landscapes - meadows and forest pastures which are used for grazing. Further away between cliffs and fields there are hillside and cliff bottom herb-rich forests, in which the Small-leaved Linden (Tilia cordata), the Hazel (Corylus avellana) and the Norway Spruce (Picea abies ) thrive. As the richness of the area's soil varies and there are large changes in altitude, the area's nature is diverse and the landscape is interesting.
The River Byabäcken is a tributary of the River Sipoonjoki, and flows through the Natura site for about 4 km. Part of the River Byabäcken flows through open farm landscape in its original river bed groove. The area is part of Sipoo's valuable cultural landscape. Parts of the river's course have been straightened and some of the cultural farm landscape has changed to forest as meadows which have not been grazed and unused fields have become wooded.
The Valley's Birds
Bird density along the river bank is very high, especially in areas dominated by deciduous trees. The deciduous forests and shrubbery provide nesting places for many birds in the Sylvidae family. Visitors may also hear a choir of thrush nightingales (Luscinia luscinia) singing by the brook. Other night singers are common to the area as well. Down in the valley you may spot the grey-headed woodpecker (Picus canus) and the ortolan bunting (Emberiza hortulana). The spotted nutcracker's (Nucifraga caryocatactes) soft croaking can often be heard on the forest's fringes.
The biodiversity of forest nature in the valley also adds to the value of the forest in the surrounding area as a bird habitat. In addition to being home to the basic bird population the area also boasts some demanding bird species which have adapted to a specific forest environment. These species include the greenish warbler (Phylloscopus trochiloides), which thrives in lush forests, the red-breasted flycatcher (Ficedula parva) and the three-toed woodpecker (Picoides tridactylus), which prefer old spruce forests, and the nightjar (Caprimulgus europaeus) and the woodlark (Lullula arborea), which favour peaceful rocky areas.
Maintaining the Heritage Landscape
The areas heritage landscape developed through the effects of traditional farming. Many plant, fungus and animal species inhabit these heritage landscapes, and the area will not remain so rich in biodiversity if it is not managed and cared for. To ensure that the heritage landscape in Byabäcken Valley remains as such it is actively maintained: Forest pastures and meadows are kept clear by having horses graze in them. Areas which are overgrown are cleared. As well as maintaining the heritage landscape Metsähallitus tries to keep all the area's fields farmed.
The heritage landscape in Byabäcken River Valley was restored between 2001 and 2004 with EU Life funds.
The eagle owl, the iconic animal of Sipoonkorpi, is the largest owl species in Europe. The thickest breeding population in Finland is found in the southern and southwestern parts of the country. The eagle owl also thrives in the rocky forests of Sipoonkorpi. It builds its nest on the ground - often on a small projection of a precipice, at the foot of a tree or in the shelter of the roots of a tree blown down by the wind.
The thick, projecting "eye brows" are the distinguishing features of the eagle owl. Its plumage is speckled with yellowish brown and black, and its eyes are orangey red. The female is considerably larger in size than the male.
The eagle owl feeds on hares, small mammals and birds. The eagle owl couple does not necessarily nest every year. If the winter has been cold and there are not many rodents to feed on, they do not nest. The female sits on the eggs for five weeks and the male brings it food daily. A total of 2-4 chicks hatch in late winter or spring. The eagle owl's nest must not be disturbed, as it easily abandons its nest. Unable to fly, the chicks leave the nest at the age of roughly six weeks. They learn to fly at the age of about two months and do not become independent until late summer or autumn.
Due to the decline in numbers, the classification of the eagle owl was changed from least concern to near threatened in the review of the red list species in 2010.