Which layer of a tree is critical for growth and is located just beneath the bark?

The cambium is a vital layer of a tree situated just beneath the bark, and it plays a crucial role in the growth of the tree. This layer consists of actively dividing cells that contribute to the development of new phloem and xylem cells. The cambium allows the tree to grow in diameter through the production of new tissues, which is essential for its overall health and structural integrity.

As new phloem cells form on the outer side, they are responsible for transporting nutrients produced by photosynthesis. On the inner side, the cambium produces xylem cells, which are crucial for transporting water and minerals from the roots to the leaves. Thus, without the cambium, a tree would be unable to increase its girth or to replace old and dying cells, ultimately affecting its growth and survival.

Phloem, while important for nutrient transport, is produced by the cambium. Xylem, although vital for water transport, is also a product of cambial activity. Heartwood, on the other hand, consists of non-living, old xylem that has ceased to function in water transport, so it is less relevant to growth. The primary role of the cambium is essential for a tree's ability to