The oak in Vårdsätra
Even though Vårdsätra nature reserve is one of Sweden’s oldest, it is not nearly as old as the giant English oak that grows here. Nobody knows exactly, but its age has been estimated to 500–600 years meaning it stood here already during the late Middle Ages.
An ancient giant
- Age: probably 500–600 years
- Height: 29 m
- Diameter: 2,4 m
- Circumference: 7,5 m
When an English oak tree has become more than 200 years old, it usually does not get much taller. On the other hand, it can continue to grow wider for many years. The circumference of this oak is no less than 7,5 meters, meaning that 5 average height people are needed to fully reach around its stem.
Three species native to Sweden
The scientific name of the English oak is Quercus robur, and it is included in the Fagaceae family. Even though that family consists of over 900 species, only three of them are native to Sweden: English oak (Q. robur), sessile oak (Q. petraea), and European beech (Fagus sylvatica). English oak and sessile oak are quite similar looking, but you can use the stalks of their acorns to tell them apart. English oaks have long stalks while sessile oaks have very short ones. Additionally, the sessile oak is rare in this part of the country.
Where can you find the English oak?
English oak can be found in almost all of Europe, except for the southernmost and northernmost parts which means northern Sweden is not the place to be if you are looking for oaks. Here in Uppland they are quite common, and they are usually found in deciduous forests, mixed forests, or in open landscapes such as grasslands where they can endure storms due to their deep, strong root systems.
For how long have English oak trees grown here?
About 9000 years ago, the English oak started establishing in southern Sweden. Little by little it spread further north, and it probably took an additional 1000 years before it reached Uppland. It used to be a more common species; pollen analyses show it has decreased in Sweden during the last 2000 years, and with a faster pace the last few centuries.
Royal wood and food for pigs
The wood of English oak is more resistant to rotting than all other Swedish wood types. It is also strong and possible to bend, making it perfect for the construction of ships. That is why the Swedish 16th century king Gustav Vasa suddenly decided all oak trees belonged to him. The crown kept the ownership of the trees until the 19th century, meaning the giant oak of Vårdsätra has probably been a property of the royalties for half of its life.
Acorns are the fruits of the oak, and they contain tannins that can give stomach issues and other symptoms of poisoning in humans and other animals if they are eaten. Pigs however seem to be somewhat resistant to the tannins, and historically the farmers in southern Sweden let their pigs stray in deciduous forests where they would feed on acorns and beechnuts.