Structure of root branches in norway spruce with respect to soil drainage

Abstract

We studied root branch structure in uprooted spruce trees (Picea abies [L.] Karst.) in the localities Hnilé Blata (the High Tatra Mts.) (waterlogged) and Zemská, (the Low Tatra Mts) (well-drained). After cleaning the root plates, we measured the number, diameter and length of individual root branches. Individual root branches were classified in twelve diameter classes - according to their diameter measured in the middle of root branch length. Mean values of absolute frequency of root branches in the first eight root-diameter classes (0.2-12.0 cm) were higher in spruce trees growing on well-drained sites, but for the same sites, we found out lower mean values of absolute frequencies of root branches in the last four root-diameter classes (12.1-30.0 cm). We found out unproportionally higher mean values of root branch length in all root-diameter classes in spruce trees growing on waterlogged sites. The mean value of total length of root branches was two times higher in the first root-diameter class (0.2-1.0 cm); and, similarly, mean values of total length of root branches were noticeably higher in the last four root-diameter classes (12.1-30.0 cm) in spruce trees growing on waterlogged sites. Based on our results, it seems that there is practically no difference in total mean length of root branches (all root-diameter classes together) with diameter exceeding 1 cm between spruce trees growing on waterlogged and well-drained sites. According to our results, spruce trees growing on well-drained sites form shorter root branches in the thinner root-diameter classes, but the frequency of these root branches is higher in comparison with spruce trees growing on waterlogged sites. Therefore, the total length of root branches (with diameter exceeding 1 cm) in spruce trees growing in waterlogged and well-drained sites is almost the same.