1 This paper evaluates the role of soil drainage in tree seedling
performance at a site being restored from Calluna vulgaris moorland to
Pinus sylvestris woodland, in Glen Affric, Scotland. The investigation
focuses on the relationships between height of planted seedlings, type
of ground vegetation and drainage conditions. 2 Slope, aspect, and soil
depth were assessed as potential surrogates for direct measures of soil
drainage, all of which were derived from digital terrain data. 3 Six
variables related to drainage were recorded at 58 seedling locations
and used in a factor analysis to understand links between soil moisture
conditions, topographic variables and soil depth characteristics. 4
Factor analysis generated two factors that accounted for 70.5% of the
variance in the correlation matrix of these variables: Factor 1
correlated strongly with variables that controlled peat accumulation
and Factor 2 correlated strongly with topographic controls upon
drainage patterns.
5 These two factors explained a significant amount of the variance in
height of the Pinus seedlings planted at these locations. Significant
differences were found between the factor scores associated with
different types of ground vegetation, as well as between the seedling
heights observed at locations with different vegetation types.
6 Multiple regressions were developed that indicated that slope,
aspect, and soil depth were significant as independent variables in
models where soil moisture content and aerobic soil depth were the
dependent variables.