Intensive land use with resulting reduction and loss of habitats is one of the reasons behind the loss of biodiversity that the world is currently facing. In Sweden, natural forests are scarce today because of intensive forestry, which has led to a decline in many forest habitats, such as dead wood. One organism that has been heavily affected by loss of habitat is the white-backed woodpecker. This bird prefers deciduous forests rich in dead wood and more than 200 threatened species of insects and other organisms also prefer this habitat. For this reason the white-backed woodpecker is considered an umbrella species. In order to restore deciduous forests rich in dead wood and thereby favor species depending on this, dead deciduous wood is created artificially, often by ring-barking. Studies of artificially created deciduous dead wood are still largely lacking. The aim of this study is to contribute to research in deciduous forests by comparing ring-barked birches to naturally dead birches in terms of density of insect holes and woodpecker foraging activity (in general, not of a certain species). Insect holes were counted up to 2.2 meters and woodpecker foraging activity was scored on a scale from 1 - 5 on 144 ring-barked and 132 naturally dead birches across six sites in Uppland, Västmanland and Gästrikland, Sweden. Ring-barked birches did not have as many insect holes/surface area as did naturally dead trees and this differed between sites. Woodpecker foraging activity, on the other hand, did not differ between the dead wood categories but differed between sites. Further, both density of insect holes and woodpecker foraging activity increased with the diameter of the trees and woodpecker foraging activity also increased with number of insect holes/surface area across both dead wood categories. The results suggest that ring-barked birches do not fully mimic naturally dead birches when it comes to insect abundance but woodpeckers forage on ring-barked birches to a similar extent as on naturally dead birches. Thus, ring-barking of birches does not fully replace naturally dead wood of birch but it can serve as an important complement.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-474775 |
| Date | January 2022 |
| Creators | Eriksson, Anna |
| Publisher | Uppsala universitet, Institutionen för biologisk grundutbildning, Anna Eriksson |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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