Which local environmental factors are most important
in determining the health and success of twinflower (Linnaea borealis)
in northern Scotland?
MSc thesis (Biodiversity and Conservation)
Laurie Pomeroy
University of Leeds
September 2010
Abstract
Background and aims Twinflower (Linnaea borealis) populations in Scotland are largely uni-clonal and reproductively isolated, putting them at risk of disease, sexual failure and ultimately population collapse. It is widely proposed that the only way to secure the future of rare, vegetative species is to encourage reproduction through mixed clone planting and reintroductions. It is therefore critical to fully understand the optimum conditions for twinflower growth, to increase the chances of such ventures succeeding, and to help existing populations develop. Previous studies have simply looked at the variables under which twinflower can survive, whereas this study aims to understand what makes it flourish.
Methods Twinflower abundance was measured against the following variables: woodland history, woodland size, patch isolation, twinflower patch size, climate, aspect, altitude, grazing, soil pH, litter depth, shrub height, canopy and understory composition, trees density and light levels.
Key results Twinflower abundance was significantly correlated with aspect, shrub height, canopy density and the number of trees within 20m². It is positively associated with the Trientalis europaea, Deschampsia flexuosa, Festuca ovina and Rhytiadelphus triquetrus. Negatively associated species were Pleurozium schreberi, Ptilium crista-castrensis, Erica cinerea, Erica tetralix, Calluna vulgaris, Pteridium aquilinum, Carex arenaria, C.binervis and Luzula sylvatica.
Conclusions When managing existing twinflower habitats, or choosing new ones, the following factors are desirable, to enable twinflower to reach its potential. A southerly aspect; a mature Pinus sylvestris canopy, with a cover of 60-70%, creating dappled shade; a shortly cropped and sparse shrub layer, maintained by moderate grazing pressure and stated canopy cover (high percentage grass cover is most favourable); the presence of Vaccinium myrtillus, Empetrum nigrum, Deschampsia flexuosa, Trientalis europaea and Melampyrum pratensis may provide a helpful indicator of suitable habitat; the presence of certain species should be an indication of unsuitable habitat. For example Carex spp, Juncus spp., Erica cinerea, Pteridium aquilinum, Pleurozium schreberi and Ptilium crista-castrensis. The best twinflower sites had the
majority of these variables together.
Pages about woodland ground flora on this site
- Species profile: Lesser Twayblade
- Species profile: Creeping ladies tresses
- Species profile: Twinflower
- Vascular Plants occurring in Glen Affric
- Vascular Plants, Ferns and Clubmosses recorded on Dundreggan
- Which local environmental factors are most important in determining the health and success of twinflower (Linnaea borealis) in northern Scotland? - results of a research project in 2010
- Ground flora regeneration in replanted native Caledonian woodland in
Glen Affric
- results of a research project in 2006
- The Trees for Life Woodland Ground Flora Project
- Return of the Flowers Appeal
- Flowers of the Forest Update Spring 2009
- Flowers of the Forest, Caledonia Wild! Winter 2007
- Woodland Ground Flora, Caledonia Wild! Summer 2007
- Ground Flora Propagation Trials, Caledonia Wild! Winter 2006-07
- Regenerating woodland flora - a next stage in the forest restoration process, Caledonia Wild! Summer 2002
Back to Scientific Research in the Caledonian Forest