Root Dynamics in a Young Scots Pine Stand in Central Sweden

Abstract

The dynamic changes of root systems were investigated in a 15-20 yr old Scots pine Pinus sylvestris stand at Ivantjarnsheden in Central Sweden. Two independent strata were designated for the purposes of sampling, one of them dominated by clones of Calluna vulgaris and the other by Cladonia lichens. Considerable variations in the fine-root quantity during the season were recorded for P. sylvestris, C. vulgaris and Vaccinium vitis-idaea. The root dynamics of P. sylvestris in the < 1 mm diameter class were assessed via five quantitative variables: weight, length, volume surface area and root-tip number. Regression relationships were developed. The annual production in the fine roots (<2 mm in diameter) of P. sylvestris, C. vulgaris and V. vitis-idaea was estimated as 183 ? 26, 38 ? 16 and 135 ? 36 g m-2 respectively, in the total stand. The cumulative annual total in dead fine roots was 121 ? 20, 25 ? 13 and 104 ? 25 g m. Estimates, which are optimal figures derived from different calculation methods, are given ? one standard error. These results suggest a production and supply of dead fine-root material to the soil, considerably higher than that conventionally expected.