Vegetation and Revegetation Techniques Flashcards

What is the minimum vegetative cover percentage typically required to meet final stabilization standards under NPDES permits?

Answer: 70%

Most NPDES Construction General Permits define final stabilization as achieving a uniform perennial vegetative cover with a density of at least 70% of the pre-disturbance vegetative cover or 70% vegetative cover overall.

Soil compaction on a construction site affects revegetation success primarily by:

Answer: Reducing pore space and limiting root penetration, water infiltration, and air exchange needed for plant establishment

Compacted soils have reduced pore space, which limits root penetration, restricts water infiltration, and reduces oxygen availability, all of which severely impair plant establishment and growth.

Before seeding a disturbed slope, the topsoil should ideally be:

Answer: Loosened by tillage or scarification to a depth of 3-4 inches to improve seed-to-soil contact and infiltration

Loosening compacted subsoil through tillage or scarification creates a seedbed with adequate pore space for root penetration, good seed-to-soil contact, and improved water infiltration.

What is dormant seeding and when is it appropriate?

Answer: Seeding in late fall after the ground has cooled enough that seeds will not germinate until spring

Dormant seeding applies seed in late fall when temperatures are too cold for germination, allowing seeds to overwinter and germinate naturally in early spring when conditions become favorable.

Hydromulch or bonded fiber matrix products provide superior erosion control compared to straw mulch primarily because:

Answer: They form a cohesive, erosion-resistant mat that bonds to the soil surface and does not blow away

Bonded fiber matrix and hydromulch products form a cohesive, interlocked fiber matrix that bonds to the soil surface, providing superior resistance to displacement by wind and rainfall compared to loose straw mulch.

What soil pH range is generally optimal for establishment of most turf and cover crop species used in revegetation?

Answer: 6.0 to 7.0

Most turf and cover crop species used in revegetation grow best in the slightly acidic to neutral pH range of 6.0 to 7.0, where nutrient availability and microbial activity are optimized.