ISA Certified Arborist Practice Exam

What is the term for the elements like copper, chlorine, and boron that are required by trees in large amounts?

1. Injections

2. Macronutrient

3. Infiltration Rate

4. Water Holding Capacity

The correct answer is: Macronutrient

The correct term for elements such as copper, chlorine, and boron that are required by trees in large amounts is macronutrient. Macronutrients are the essential nutrients that trees need in relatively large quantities to support crucial physiological processes, including growth and development. These nutrients typically include nitrogen, phosphorus, potassium, along with some secondary nutrients like calcium, magnesium, and sulfur. While the other options refer to different concepts in arboriculture and plant health, they do not correctly define the requirement of elements in large amounts. Injections refer to a method used to deliver nutrients or protect against pests through the tree's vascular system, but they do not categorize the nutrients themselves. Infiltration rate describes how quickly water can penetrate the soil, which is important for soil health but not directly related to nutrient requirements. Water holding capacity indicates the soil's ability to retain moisture, which affects plant health but, again, does not pertain to the classification of nutrients. Thus, macronutrient is the accurate term that highlights the significance of essential elements necessary for tree vitality.