FM Soil Science & Hydrology Flashcards
7 cards from real FM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 FM Soil Science & Hydrology flashcards as text
Which soil property is the best indicator of compaction risk from heavy logging equipment?
Answer: Bulk density
Bulk density measures the mass of dry soil per unit volume; higher bulk density indicates less pore space and greater compaction, which restricts root growth and water infiltration.
In forest hydrology, Best Management Practices (BMPs) are primarily designed to:
Answer: Protect water quality during and after harvesting operations
BMPs are operational guidelines that minimize soil disturbance and protect water quality by reducing sediment, nutrient, and chemical inputs to streams during forestry activities.
What is 'interflow' (also called throughflow) in a forest watershed?
Answer: Lateral subsurface water movement through the soil during storm events
Interflow is the lateral movement of water through upper soil horizons during rainfall events when vertical percolation is slower than infiltration, contributing to streamflow without reaching the surface.
Which process in the forest nitrogen cycle converts atmospheric nitrogen (N₂) into plant-available forms?
Answer: Nitrogen fixation
Nitrogen fixation, carried out by specialized bacteria (e.g., Rhizobium, free-living Azotobacter) and some cyanobacteria, converts inert N₂ gas into ammonia that plants can use.
In a forested watershed, the water table typically exhibits which seasonal pattern?
Answer: Rises in winter/fall when trees are dormant and falls in summer
During dormancy, tree transpiration nearly stops, allowing precipitation to recharge groundwater and raise the water table; in summer, high transpiration draws water down.
What type of soil erosion is most commonly associated with forest roads and skid trails?
Answer: Rill and gully erosion from concentrated flow
Forest roads concentrate runoff into channels where water velocity increases, carving rills and gullies that deliver large sediment loads to nearby streams.
What is the primary soil-related concern when logging operations are conducted during wet soil conditions?
Answer: Soil compaction and rutting that reduce long-term site productivity
Wet soils have less structural strength, making them highly susceptible to compaction from heavy equipment, which reduces pore space, water infiltration, and root growth for future tree crops.