B.F. Bachelor of Forestry Forest Soils 3

Question 1

What is the primary reason forest soils experience much lower erosion rates than adjacent agricultural soils?

Accepted Answer

Organic matter and root networks bind soil and absorb raindrop impact energy

Answer

The O horizon, dense root networks, and high organic matter content in forest soils absorb raindrop kinetic energy and physically bind soil aggregates, drastically reducing erosion.

Question 2

How does prescribed fire generally affect soil nitrogen in the short term?

Accepted Answer

It causes a net loss of nitrogen through volatilization of organic nitrogen compounds

Answer

Fire volatilizes organic nitrogen at temperatures above 200°C, resulting in a short-term net loss of nitrogen from the ecosystem, though ash residues may temporarily increase pH.

Question 3

Which practice is most effective for maintaining soil productivity on a timber harvest site?

Accepted Answer

Retaining slash and organic debris on the harvest site

Answer

Retaining slash and organic debris protects the soil surface from erosion, moderates temperature and moisture, and returns nutrients to the soil as residues decompose.

Question 4

Which soil property does pH most directly affect in forest soils?

Accepted Answer

Nutrient availability and soil microbial activity

Answer

Soil pH controls the solubility and plant availability of most macro- and micronutrients and strongly influences the composition and activity of soil microbial communities.

Question 5

What is a soil catena in the context of forest soils?

Accepted Answer

A sequence of related soil profiles across a hillslope reflecting changes in drainage and soil development

Answer

A soil catena describes the systematic sequence of soil profiles found across a hillslope, where topographic position affects drainage, organic matter accumulation, and pedogenic development.

B.F. Bachelor of Forestry Practice Test

B.F. Bachelor of Forestry Practice Test

B.F. Bachelor of Forestry Forest Soils 3