Mountain ash (Sorbus aucuparia L.) root system morphogenesis

An analysis is made of the root system morphogenesis and architecture in several tens of European mountain ash trees aged up to 60 years at seven different sites. Although the root system variability is considerable, certain dependences can be derived. European mountain ash forms an anchoring root system. Limiting factors of the root system morphogenesis are the groundwater table (roots do not penetrate into soil horizons affected by underground water), prevailing direction of wind (elliptic root system develops in the wind direction), and the slope (in the uphill direction the roots are shorter, exhibit the more or less horizontal growth and reach into deeper soil horizons than roots growing in the downhill direction). An unambiguous correlation was found between the rooting depth of anchor roots and the number and reach of lateral roots (the longer the anchors, the fewer the lateral roots and the smaller their reach). The shorter the anchor roots, the more intensive the branching of not only the anchors themselves but also of superficial roots.