Old hollow oaks are popular residences for a large number of insects, especially beetles. At an inventory of grazing land in Turkey 25 hitherto unknown species of beetle have been found.
"Most of them would disappear if the trees were to be cut down, and the risk is great," says project leader Nicklas Jansson, beetle ecologist at Linkφping University (LiU) in Sweden.
In Turkey there are 18 species of the oak family, Quercus. Nicklas Jansson and his co-workers, researchers and graduate students from two Turkish universities, have spent five years collecting beetles from oak trees in four large pastures in the south of the country near the border with Syria. These areas, 1,200-1,500 metres above sea level, are important for sheep and goat farming, but are now threatened by felling to make way for productive forest management.
As with all felling there is a major risk that some species become extinct since the oak dwelling beetles stay so faithful to their biotope.
"Some of the species seem to have a very low motivation to leave and find a new oak," says Nicklas Jansson.
That new species would be found among the fairly popular beetle families that were looked at was a surprise. Most of the newly discovered beetles belong to the Elateridae and Tenobrionidae families and have been identified by some 20 specialists across Europe. The results will be presented at a conference on oak ecology that LiU arranges with Suleyman Demirel University and Adiyaman University. The conference takes place 1st to 3rd of June in Isparta.
Nicklas Jansson estimates that the oak biotopes in Turkey are 30-50 percent richer in species than in Sweden. He sees three reasons for the greater diversity: a climate that has allowed species to hibernate during the ice ages; the topography which creates many barriers in the form of mountain ranges and other obstacles to the mixing of species and the geographic location as a bridge between Asia and Europe.
In a follow-up project the oak fauna of seven countries is to be compared, in Israel, Turkey, Italy, France, UK, Czech Republic and Sweden.
The oaks in the Turkish pastures are pollarded much like lime trees and ash trees in Sweden. Shepherd people prune the trees in July and during the dry season use the leaves as feed for sheep and goats while the branches become fuel. Thanks to pollarding, many of the oaks are hollow and contain wood mould, a very rich compost of decomposed wood, fungi, excrement and remains of dead animals.
The insects are collected by two types of traps, one which is mounted up in the trees to catch flying insects and one which is buried in the wood mould. The collection is done by students from the local universities.
"I hope that in finding new and unique species we will get the Turkish forestry authorities to open their eyes to their oak treasures and to begin conservation work in the most valuable areas," says Nicklas Jansson.
More information can be found at: http://ormanweb.sdu.edu.tr/oak/index.html
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