The effects of fragmentation and herbivory on ecology and genetics of Scots pine and associated ground flora

Our woodland research focuses primarily on impacts of fragmentation and links this to grazing management (in pine and birch) which is the most important factor driving native woodland dynamics in Scotland. Lack of information on genetic variation in fragmented native woodlands may compromise predictions of species adaptation to environmental change and the appropriateness of different management measures. Preliminary findings for Scots pine and associated flora indicate spatial structuring in genetic variation at a range of scales, depending on species characteristics (e.g. seed dispersal mechanisms), which needs to be taken into account when designing biodiversity conservation action.

One of the aims of our woodland grazing research is to define the basis of plant resistance to different herbivores, which is fundamental for defining appropriate management. We have found that the chemical composition of pines (influenced by genetic variability), differentially affects herbivores. For example, monoterpenes confer resistance to seedlings from slugs; capercaillie forage less on trees that are high in monoterpenes and low in needle cations, particularly magnesium; but voles are not susceptible to any monoterpene-based resistance.

New work is quantifying genetic and phytochemical differentiation of seedlings from 21 natural pine populations across Scotland, using a newly developed set of microsatellite markers and extended analysis of monoterpenes on which the current ‘Caledonian pine seed zone’ regulations are based. This work is using a common garden approach (collaborating with National Trust for Scotland (NTS)) to investigate the extent to which source populations are likely to adapt to changing climatic conditions, in terms of adaptive traits such as growth and timing of bud burst.

Principal coordinates plots for AFLPs showing genetic differentiation between: a) Speyside and Deeside populations of the ant-dispersed Melampyrum pratense either side of the Cairngorm massif; b) clustering of genetically similar individuals into distinct patches (A-D) of Pyrola minor within one woodland (Anagach, Speyside).

Contacts

• Dr Glenn Iason
• Dr Pete Hollingsworth