Factors Affecting the Spatial Distribution of Rowan (Sorbus aucuparia) Regeneration in the Caledonian Pine Forest
In 2001, Emily Wilkins, a student from the Geography Department at Edinburgh University, carried out research on the distribution of regenerating rowan trees in the Coille Ruigh na Cuileige exclosure in Glen Affric.
Here is Emily's abstract of her work, from her dissertation, which was completed in May 2002:
Abstract
This study investigates the factors affecting spatial distribution of rowan (Sorbus aucuparia) within a native pineforest. This is important as broadleaved trees are an integral part of the pinewood ecosystem, and greater understanding of their role is needed for successful forest restoration and for the maintenance of biodiversity.
Fieldwork was undertaken within a fenced deer exclosure in Glen Affric. Maps were produced showing rowan distribution in relation to tree canopy cover and gaps. A quadrat-based survey considered the effects of environmental conditions on rowan abundance and growth. Observations indicated that rowan regeneration was more prolific than that of any other species. The majority of seedlings were found growing in shady conditions, clustered on gentle slopes where the ground vegetation was dominated by ericaceous shrubs. Rowan saplings (greater than 1.3m tall) were found mainly on gently sloping, undisturbed ground within canopy gaps. Some factors such as soil depth were found to influence rowan regeneration independently of light conditions. The distribution of rowan seedlings is therefore influenced by a complex interaction of different factors.
It seems that the shade environment favours the germination and establishment of rowan seedlings but later limits sapling growth. Rowans are able to grow taller and reproduce only when released by the creation of treefall gaps. If planting is required during forest restoration, saplings are best placed within canopy gaps in order to contribute to soil improvements and enable the regeneration of Scots pine. With reduced browsing pressure, the proportion of mature rowans within the pine forest will be greater, as in the past. This will contribute positively to biodiversity.
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Last updated: Wednesday, 25-Aug-2010 15:59:44 BST