B.F. Bachelor of Forestry Forest Soils 2

Question 1

Which macronutrient is most commonly limiting to tree growth in boreal and many temperate forest soils?

Accepted Answer

Nitrogen

Answer

Nitrogen is typically the most limiting macronutrient in boreal and temperate forests because slow decomposition rates limit nitrogen mineralization from organic matter.

Question 2

What type of symbiotic association do most conifers and many hardwoods form with soil fungi to enhance nutrient uptake?

Accepted Answer

Mycorrhizae

Answer

Mycorrhizae are mutualistic root-fungus associations that greatly enhance the absorption of phosphorus, nitrogen, and water in exchange for plant photosynthates.

Question 3

What is humus?

Accepted Answer

Stable, well-decomposed organic matter that improves soil structure and fertility

Answer

Humus is the dark, stable end product of organic matter decomposition that improves soil structure, water retention, CEC, and nutrient availability.

Question 4

Which biological process converts atmospheric nitrogen (N₂) into plant-available ammonium in forest soils?

Accepted Answer

Nitrogen fixation

Answer

Nitrogen fixation is performed by specialized bacteria and cyanobacteria that enzymatically reduce atmospheric N₂ to ammonia, the first step toward plant uptake.

Question 5

How does soil compaction from heavy logging equipment primarily affect forest regeneration?

Accepted Answer

It reduces soil porosity, limiting root penetration and water infiltration

Answer

Compaction reduces pore space, restricts oxygen availability, impedes root penetration, and decreases water infiltration, all of which hinder seedling establishment and early growth.

B.F. Bachelor of Forestry Practice Test

B.F. Bachelor of Forestry Practice Test

B.F. Bachelor of Forestry Forest Soils 2