Other Tree Biology Facts

Cambium is a layer of tissue responsible for the tree's growth, generating new bark and wood, increasing the diameter of the roots and stem. Within the Cambium is the Xylem (transporting water and nutrients) and outside the Cambium is the Phloem (transporting sugars and organic compounds). Darker, tougher hardwood is made from dead cells reinforced with lignum, tannins and other toughening chemicals.

Nodules that form on the roots of Black Alder contain apple-sized bacterial growths, which absorb nitrogen from the air and give the tree this important element.