Seasonal patterns of fine-root production and mortality in Prunus avium in Scotland

The seasonal pattern of root dynamics in Prunus avium (L.) L. (wild cherry) was determined using mini rhizotron observations of the production and disappearance of individual roots over a 2-year period at a site in northeast Scotland. The largest percentage of observed root appearance and disappearance took place at a depth of 10 cm (34%) compared with approximately 20% at each of three lower depths down to 30 cm. Of the 37 574 roots·m^–2 produced in total over the 2year observation period, some 78% disappeared during the study. Over 90% of new root production occurred between March and October. Root production was highest in June 1998 (2263 roots·m^–2) and lowest in January of 1998 and 1999 (31 roots·m^–2). Combination of these data with counts of root disappearance showed that there was a net increase in root numbers per tree between March and June. From June onwards, the rate of root disappearance exceeded the rate of production. Thus, any annual increase in the number of roots depended upon a short period of major root production in late spring – early summer.