Nature in Ruissalo
Have respect for nature.
Stay on the marked routes, keep your pets on a leash and don’t harm the plants or animals. Further information concerning the nature conservation decree can be found in the signs next to the protected area.
The history of Ruissalo has its roots in the island’s nature and together they form a unique combination. The island’s natural and cultural values are secured for the generations to come through legal regulations and conservation planning.
A history shaped by the oak
Interest in the conservation of oak forests grew during the 16th century, as oak was considered a valuable material in ship construction. During the Middle Ages in Sweden-Finland, fines were imposed for cutting down an oak suitable for ship construction. In 1647, a law was passed declaring that all oak trees belong to the crown. Since 1750, the forests of Ruissalo have provided shelter to grazing livestock. During this period, oak trees could thrive only in areas free of grazing, such as yards. To ensure the regeneration of oak trees, grazing was forbidden at the beginning of the 20th century. Even with these laws in place, the impact of grazing on the oak population is still visible today.
The oak forest – a haven of diversity
An old oak forest represents biological diversity at its finest. Every species has a central role in the ecosystem. An old oak tree hides a great amount of food suitable for woodpeckers. Through their foraging activities, woodpeckers form cavities in the trees, which in turn are used as nest holes by tawny owls, stock doves, yellow-necked mice and Daubenton's bats. The droppings of various hosts in the nest holes accumulate and create the habitat vital for the rarest species in Ruissalo, the hermit beetle.
During its lifespan, which can be several hundred years, an oak tree offers breeding and feeding habitats for thousands of species. Roughly five hundred species of insects, many of which are endangered, are dependent on the oak. Especially the oldest oaks in Ruissalo – the ones already decaying from the core – create sanctuaries for several species of lichens, fungi and invertebrates. Many of them are rare in other parts of Finland, but highly abundant in these micro-habitats of Ruissalo.
In addition to having the largest oak and temperate broadleaf forests in Finland, Ruissalo offers a range of other important habitats, such as grasslands, herb-rich forests, inlets and bays and many others. The large variety of habitats further increases the magnificent diversity on this island. The City of Turku works to conserve the natural values of the island through its annual management planning.