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

Accelerates surface runoff velocity

Answer

Decreases soil organic matter content

Answer

Increases soil bulk density

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

Decreased timber productivity on adjacent uplands

Answer

Reduced soil carbon storage in upland areas

Answer

Decreased wildlife diversity far from the harvest

Question 3

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

Accepted Answer

Precipitation, parent material, and organic matter decomposition

Answer

Wind speed, canopy height, and wildlife activity

Answer

Slope aspect, air temperature, and timber species only

Answer

Road density, harvesting frequency, and fertilizer application

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

Harvesting during the wet season for easier equipment movement

Answer

Removing all vegetation in the riparian zone to allow stream access

Answer

Increasing road gradient to speed water removal from the site

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

Water stored in mineral soil pores

Answer

Lateral water movement in shallow soil layers

Answer

Water infiltrating to deep groundwater

Question 6

What minimum riparian buffer width do most US state forestry Best Management Practices recommend for protecting small perennial streams during timber harvest?

Accepted Answer

50–100 feet

Answer

10–15 feet

Answer

200–300 feet

Answer

500 feet or more

Question 7

The rate of forest floor litter decomposition is primarily controlled by which set of factors?

Accepted Answer

Temperature, moisture availability, and microbial/fungal activity

Answer

Tree species composition alone

Answer

Wind speed and prevailing wind direction

Answer

Canopy closure percentage and stand age only