FM FM Soil Science & Hydrology 3

Question 1

How does coarse woody debris (CWD) on the forest floor primarily benefit watershed hydrology?

Accepted Answer

Retains soil moisture and reduces erosion by slowing runoff

Answer

Coarse woody debris acts as a physical barrier that slows surface water movement, promotes infiltration, retains moisture, and reduces erosion by intercepting runoff.

Question 2

What is the primary hydrological concern when clear-cutting occurs in or near riparian zones?

Accepted Answer

Increased stream sedimentation and elevated stream temperatures

Answer

Removing riparian vegetation eliminates shade (raising stream temperature), disrupts root networks that stabilize banks, and allows sediment from exposed soils to enter streams.

Question 3

Forest soil pH is primarily influenced by which combination of factors?

Accepted Answer

Precipitation, parent material, and organic matter decomposition

Answer

Precipitation leaches base cations, lowering pH; parent material determines base mineral supply; and decomposing organic matter releases organic acids that further acidify forest soils.

Question 4

Which field practice best reduces sediment delivery to streams during timber harvesting on slopes?

Accepted Answer

Installing water bars and cross-drains on skid trails

Answer

Water bars and cross-drains intercept concentrated flow on skid trails and divert it into vegetated areas before it gains sufficient energy to transport large sediment loads to streams.

Question 5

Evapotranspiration (ET) in a forest ecosystem refers to:

Accepted Answer

The combined loss of water to the atmosphere via soil evaporation and plant transpiration

Answer

ET is the sum of direct evaporation from soil and canopy surfaces plus transpiration through plant stomata, and typically represents the largest water output from a forested watershed.

(FM) Forest Management Certification Practice Test

(FM) Forest Management Certification Practice Test

FM FM Soil Science & Hydrology 3