What role does the cambium layer play in trees?

The cambium layer is crucial for the growth and development of trees, particularly in contributing to secondary growth. This layer is a thin layer of meristematic tissue located between the bark and the wood, and it plays a vital role in producing new cells. As the cambium divides, it contributes to the formation of new xylem (wood) to the inside and new phloem (bark) to the outside. This process increases the overall diameter of the tree, allowing it to grow thicker over time. Additionally, the cambium is essential for the tree’s ability to transport nutrients and support its structure but its primary function pertains to promoting this secondary growth.

In contrast, the roles of providing insulation, transporting water, and producing sap are associated with different tissues in the tree. The cambium itself does not provide insulation, which is a function of the bark; it also does not transport water directly, as that function lies with the xylem. While sap flow is an important aspect of a tree's health and metabolism, sap production involves other structures and is not the primary role of the cambium layer.