With several trees down after the recent storms of Dudley, Eunice and Franklin, local neighbours were busy, wielding chainsaws and making the lanes passable. As the large cross-sections of fallen tree trunks were revealed, my curiosity was piqued. We all know that you can tell the age of the tree from these rings but what causes these concentric circles? It all gets very scientific but during each season the tree grows vertically and laterally, and it is this lateral or secondary growth that causes the thickening of the stems, branches and trunk. This creates a new ring internally, which marks the cycle of four seasons or a year
Xylem is plant vascular tissue and when active this conveys water and dissolved minerals from the roots to the rest of the tree. In trees xylem builds a ring of new xylem around itself. Dead xylem becomes heartwood (the backbone of the tree) and then newer xylem is the sapwood. The age of the tree can be determined by the number of annual xylem rings at the base of the trunk.