How does secondary growth help identify the age of a stem?

Secondary growth, which occurs in woody plants, results in the formation of additional vascular tissue, leading to the increment in stem diameter over time. By analyzing the growth rings produced by this process, researchers can determine the age of a stem; each ring typically represents one year of growth. The width of these rings can also provide insights into environmental conditions during each growth period. Thus, counting the rings and assessing their characteristics allows for accurate age estimation and growth history analysis.