CF CF Watershed & Soil Conservation 2 — Questions and Answers
Question 1: Which soil horizon contains the highest concentration of organic matter in a typical forest soil profile?
- O horizon (organic layer) (Correct answer)
- B horizon
- C horizon
- R horizon
Correct answer: O horizon (organic layer)
The O horizon consists of decomposed and decomposing organic material (litter, duff) and has the highest organic matter content in a forest soil profile.
Question 2: What is the main benefit of leaving logging slash on steep slopes after harvest?
- Reduce surface erosion by intercepting rainfall and surface runoff (Correct answer)
- Increase fire risk for prescribed burns
- Accelerate site preparation for planting
- Provide browse for deer
Correct answer: Reduce surface erosion by intercepting rainfall and surface runoff
Slash covering the soil surface intercepts raindrop impact and slows overland flow, significantly reducing erosion on steep post-harvest slopes.
Question 3: Which term describes water that infiltrates the soil and moves laterally downslope through the soil matrix to streams?
- Subsurface flow (interflow) (Correct answer)
- Overland flow
- Baseflow
- Throughfall
Correct answer: Subsurface flow (interflow)
Subsurface flow or interflow is water that moves laterally through the soil above the water table and contributes to streamflow during and after storms.
Question 4: What is the primary concern with soil disturbance on highly erodible soils classified as Lands Unsuitable for Logging (LUL) in state forest practice rules?
- Irreversible loss of topsoil and long-term site productivity decline (Correct answer)
- Reduced wildlife forage availability
- Increased stand density
- Decreased timber revenues
Correct answer: Irreversible loss of topsoil and long-term site productivity decline
Highly erodible soils can lose topsoil irreversibly after mechanical disturbance, permanently reducing site productivity and causing chronic sediment delivery to streams.
Question 5: What hydrological process is primarily responsible for maintaining low flows in streams between storm events?
- Groundwater discharge (baseflow) (Correct answer)
- Overland surface runoff
- Snowmelt interception
- Canopy throughfall
Correct answer: Groundwater discharge (baseflow)
Baseflow is sustained by slow discharge of stored groundwater that continues to feed streams during dry periods between storms.
Question 6: Which practice best protects soil productivity on skid trails after timber harvesting operations are complete?
- Outsloping and seeding skid trails to establish vegetative cover (Correct answer)
- Leaving rutted trails bare for the next entry
- Installing concrete paving on high-use trails
- Treating trails with herbicide to prevent brush competition
Correct answer: Outsloping and seeding skid trails to establish vegetative cover
Outsloping directs runoff off the trail surface and establishing vegetative cover binds the soil, preventing erosion and promoting recovery of soil structure.
CF CF Watershed & Soil Conservation 2
Which soil horizon contains the highest concentration of organic matter in a typical forest soil profile?