What does the term "tree mortality" refer to?

The term "tree mortality" specifically refers to the death of trees resulting from various factors such as disease, pests, or environmental stressors like drought, fire, or extreme weather. Understanding tree mortality is vital in forestry and ecology, as it impacts forest health, biodiversity, and the overall ecosystem. This concept encompasses both natural occurrences and the effects of human activity on tree populations.

In contrast, the other options do not accurately capture the essence of tree mortality. The natural cycle of tree growth refers to the processes involved in a tree's development rather than its demise. The process of trees shedding leaves in autumn describes seasonal changes in foliage, which does not necessarily relate to the tree's health or death. Lastly, trees that are cut down for commercial purposes represent human intervention and extraction rather than natural causes of mortality. Each of these alternatives highlights different aspects of forestry and tree behavior but fails to define tree mortality accurately.