The importance of undergrowth vegetation and browsing pattern on oak seedlings

Abstract: This 30 ECTS master thesis aim was to investigate how the species composition andstructures in the understorey vegetation community affects oak seedling browsing risk,frequency and severity.The study was conducted in 10 mixed broadleaved forests in Southern Sweden. A subplotsampling inventory method over transect was used in order to evaluate browsing patternon natural regenerated oak seedlings. Data for studies was collected in July 2009. In the totalof 200 focal oak subplots evaluation, around 8 500-undergrowth vegetation speciesindividuals were carried out.The results showed that in all 10 sites together, more than half of all oaks werebrowsed and third part of all damaged undergrowth species were oaks. Undergrowthvegetation species composition and density didn’t affect browsing pattern and severity in allten forests. In all 200 focal oak subplots the most damaged undergrowth species were:Quercus sp, Sorbus aucuparia, Populus tremula, and Fraxinus sp. Browsing choice andseverity was dependant on the oak seedling height by itself and available undergrowth speciesheight in the surroundings.Oak stands should have a high amount of broadleave species in the undergrowth untilregeneration phase is over in order to provide enough oak seedlings per hectare for futurestand management without fencing.