What function does the cambium layer serve in a tree?

The cambium layer plays a crucial role in a tree's growth and development. It is a thin layer of living cells located between the bark and the wood. Its primary function is to facilitate the growth of new cells through the processes of cell division and differentiation. Specifically, the cambium generates new phloem cells towards the outside, which help transport nutrients, and new xylem cells towards the inside, which transport water and minerals.

This growth produced by the cambium contributes significantly to the increase in the girth of the tree, allowing it to become larger and support many functions necessary for its survival. By producing new layers of vascular tissue each year, the cambium also plays a vital role in the overall health and longevity of the tree, making it essential for sustaining life and growth throughout the years. This characteristic distinguishes it from the other functions mentioned in the options provided.