ISA Certified Arborist Practice Exam

What is the process by which trees convert sunlight into energy?

1. Transpiration

2. Photosynthesis

3. Respiration

4. Decomposition

The correct answer is: Photosynthesis

Photosynthesis is the process by which trees and other plants convert sunlight into energy. During photosynthesis, plants take in carbon dioxide from the air and water from the soil, and using the energy from sunlight, they transform these inputs into glucose and oxygen. The glucose serves as an energy source for the plant, supporting growth, reproduction, and various metabolic processes. This process primarily occurs in the chloroplasts of plant cells, where chlorophyll, the green pigment, absorbs light energy. The significance of photosynthesis lies not only in the production of energy for the plant itself but also in its role in producing oxygen, which is essential for most living organisms on Earth. Understanding photosynthesis is crucial for arborists and those involved in tree care because it directly affects a tree's health and growth. Trees that are healthy and capable of efficient photosynthesis are crucial for ecosystem balance, contribute to carbon sequestration, and provide oxygen, making it a fundamental concept in arboriculture.