Why does a tree grow at different rates each year?

A tree grows at different rates each year due to various environmental factors, including temperature, rainfall, and soil nutrients, which can fluctuate annually. Additionally, the tree's age, species, and health play critical roles in its growth patterns. Stressors such as pests, diseases, or competition for resources can also impact growth rates. Lastly, seasonal changes and the availability of sunlight influence the tree's ability to photosynthesize and produce energy for growth.