Roots of Trees and Woody Plants

The basic function of tree roots is to facilitate the uptake of water, with its dissolved mineral nutrients, whilst also providing anchorage, and sometimes support, in the soil where the tree is growing. Roots also supply plant hormones to the shoot system, often store starch and may be modified in various ways, such as with breathing roots, for perennation and for nitrogen fixation. In most trees, their original vertical taproots, which developed from their embryonic seed radicles, die off to be replaced by a network of superficial feeder roots. This veteran pollarded specimen of Quercus petraea (Sessile Oak) is growing on the western shoreline pasture of Loch Tay, near Killin, Scotland. In the exposed root system of Pinus nigra (Corsican Pine), there is very considerable lateral extension of several of its main roots, which have helped to stabilise the tree trunk in its precarious sandy location.