Björnö, Naturreservat

Mighty oaks, unusual beetles and a rich cultural history. These are parts of Björnö Nature Reserve, an international-class excursion destination close to urban areas!

Historic land

Björnö Nature Reserve is part of the manor landscape that has long been part of the Björnö estate. Over the centuries, the estate has had several different owners, mainly belonging to famous noble families such as Sparre, Tott and Oxenstierna. The presence of so many oak trees, to which many of the high nature values are linked, is a consequence of this long-standing noble presence in the area. The so-called regal right, i.e. the Crown's ownership of all oak trees for ship timber, did not apply to the nobility. They had the right to decide on their own oak stands. The fact that there are so many oaks around Björnö therefore has significant cultural-historical value, as they tell of the estate's long period of noble ownership.

Rich diversity

Today, the cultural oak landscape is in short supply globally. Of the Swedish distribution, Östergötland and Kalmar County have the largest areas of really old oaks and Björnö is one of these important areas. It takes about 200 years for an oak tree to start rotting on the inside and become hollow. Various wood fungi help with the decomposition on the inside of the trees. The hollows form mulm, a loose material of decomposed wood, bird droppings, leaves and other things that are very important for a number of species. The average age of the oaks on Björnö is around 150 years. A few giant oaks and large lime trees of a much higher age are found mainly in the northern part at Matängsbacken, adjacent to the avenue. The protected mistletoe grows on a few lime trees. The oak hedges contain many plants that thrive in grazed land. For example, cowslip, goosefoot, bluebell, meadowsweet, sedge, sedge grass and almond blossom. Old oaks are also an important habitat for lichens and fungi. Several unusual species have been found in Björnö, including old oak lichen, small decay lichen, dull spotted lichen, brown needle lichen, gray shield lichen and pale lichen.

Flowering meadows

There are not only oaks on Björnö's land. The seashore meadows in the nature reserve are species-rich, well-grazed land with plants such as saltwort, red fescue, creeping bent and sea elder. In spring, the salt meadows are colored in yellow and blue by flowering clover and maidenhair fern, and waders such as red-legged kittiwake and lapwing nest here. The seashore meadows are grazed by cattle and are an open and flat environment that is only broken by moraine islets with old trees scattered like small islands on the seashore meadow. The Åbyån watercourse meanders through the western part of the reserve and then flows into Rafshagsviken in the Baltic Sea. The lower parts of Åbyån are important places for spring-spawning fish species such as perch, pike and roach.

Eldorado for insects

Björnö's beetles were inventoried in the late 1990s. It turned out that more than 50 threatened species, most of them linked to the area's oak habitats, lived in Björnö nature reserve. Even then, there were several finds of leatherback beetles, which live in hollows in old deciduous trees and often signal that there are many other exciting species nearby. Other interesting beetle finds on Björnö include the brown ox, the hornets' card wing, the beech ox, the narrow-mouthed beetle, the clouded beetle, the dull flour beetle and the thorn beetle.

Within the Life project Bridging the gap, great efforts have been made in Björnö when it comes to beetles. Two extremely rare species, the greater oak beetle and the broad-banded oak bark beetle, both of which are strongly linked to areas with old oaks, have now found a new home here. The greater oak bark beetle is currently only found on a few oaks in Halltorps hage on Öland. The only place in the entire Nordic region! But through a collaboration with Nordens ark in Lysekil, oak bucks and oak bark bucks have been bred and released in their new home in Björnö's oak gardens.

Excursion destination

Within Björnö nature reserve there are good opportunities for nature experiences in exciting and varied environments. The reserve is part of the manorial landscape around Björnö Castle, with its park, avenue and surrounding fields and oak groves. It is an interesting destination from both a cultural and biological perspective. The reserve is located close to Kalmar city, only 15 minutes away by car. Parking facilities for a small number of cars are available at Matängsbacken in the northern part of the reserve. A hiking trail passes through the area along the private road Oxhagen-Matängsbacken and further west along the road to Byrum. The trail is part of a municipal hiking trail that starts from the Horsö-Värsnäs area.

LIFE project

Björnö was part of the LIFE project Bridging the gap between 2016-2022. Follow the link here to read more about the project.

LIFE Bridging the gap Link to another website, opens in new window