What is the primary purpose of the cambium layer in trees?

The primary purpose of the cambium layer in trees is indeed growth in thickness. The cambium is a thin layer of generative tissue located between the bark and the wood, and it plays a crucial role in the secondary growth of plants. It produces new cells that contribute to the increase in diameter of the tree. This is vital for the overall health and stability of the tree, as it allows it to expand and accommodate new growth as well as support the weight of additional foliage and branches.

By facilitating this growth, the cambium layer enables the tree to develop a robust trunk and larger limbs, which are essential for reaching sunlight and obtaining water through a more extensive root system. While processes like photosynthesis, water transport, and support are important for a tree's life cycle, they are not the primary function of the cambium. Photosynthesis occurs mainly in the leaves, water transport is handled by xylem, and structural support comes from the wood itself. Thus, the cambium's chief role is directly associated with the thickness and overall growth of the tree.