An Investigation into the Factors Affecting the Growth and Condition of Scots Pine (Pinus sylvestris L.) in Glen Affric

A young Scots Pine, Allt na Muic

In 1997, Mirkka Jones, a student at the Institute of Ecology and Resource Management at Edinburgh University, carried out research on the factors affecting the growth of Scots pine seedlings which had been planted by Trees for Life volunteers in Glen Affric.

Here is the summary of Mirkka's work, from her dissertation document:

Summary

The objectives of this project were to investigate the effects of grazing, soil nitrogen status, exposure and characteristics of the surrounding vegetation on the growth and condition of Scots pine (Pinus sylvestris L) seedlings planted in Glen Affric.

Field data including measurements of pine height, basal diameter and leader length, and soil and needle samples were collected in March-April 1997, by means of randomised quadrat based sampling. Twenty three 400m² quadrats were sampled. This was followed by two weeks of laboratory work involving determinations of soil moisture, pH and available nitrogen, as well as foliar nitrogen and approximate specific leaf area.

The seedlings were planted within a deer exclosure, but the accidental introduction of roe deer in 1996 meant there was some grazing damage, which resulted in a reduction of average height per unit of diameter in some sites.

Soil ammonium was probably the principle limiting plant nutrient at the site. Foliar nitrogen levels and needle chlorosis indicated that seedlings at all sites were deficient in nitrogen. The height and density of Calluna vulgaris was a significant determinant of nitrogen availability.

There was substantial browsing of west-facing needles, especially with increased exposure. Needles were retained for longer in seedlings with a good growth rate and retention may be reduced by exposure. Specific leaf area was found to decrease as average seedling height increased, probably as a response to increased light availability. Annual height growth appeared to be stimulated once pine seedlings emerged above the Calluna canopy.

Back to Scientific Research in the Caledonian Forest