PDC PDC Food Forest & Agroforestry Systems 2 — Questions and Answers
Question 1: What is the vine layer's main function in a seven-layer food forest?
- To use vertical space and grow climbing fruiting plants (Correct answer)
- To fix nitrogen at ground level
- To provide the bulk of the food forest canopy
- To suppress weeds through dense root mats
Correct answer: To use vertical space and grow climbing fruiting plants
The vine layer exploits vertical space by climbing existing structures or trees to produce fruit such as kiwi, grapes, or passionflower.
Question 2: Why are annual 'pioneer' plants important in the early stages of a food forest?
- They quickly cover bare soil, reduce erosion, and build organic matter while perennials establish (Correct answer)
- They permanently replace trees in the canopy layer
- They are the most productive plants in a mature food forest
- They provide the only source of food in the first year
Correct answer: They quickly cover bare soil, reduce erosion, and build organic matter while perennials establish
Pioneer annuals like comfrey, sunflowers, and buckwheat stabilize soil and add biomass quickly, creating conditions for slower-growing perennials to take hold.
Question 3: In US agroforestry, 'silvopasture' refers to which combination?
- Integrating trees, forage crops, and livestock on the same land (Correct answer)
- Growing trees alongside aquatic systems
- Planting hardwood trees for timber only
- A forest garden used exclusively for food production
Correct answer: Integrating trees, forage crops, and livestock on the same land
Silvopasture intentionally integrates trees with forage and livestock grazing, improving animal welfare, sequestering carbon, and diversifying farm income.
Question 4: Which PDC design concept involves placing the most frequently visited elements closest to the house?
- Zone planning (Correct answer)
- Sector analysis
- Edge effect
- Stacking functions
Correct answer: Zone planning
Zone planning divides the site into zones 0–5 based on frequency of human use, with zone 1 immediately around the house for daily-use elements like herbs and salad greens.
Question 5: What is the advantage of using 'polycultures' over monocultures in a food forest?
- Greater pest and disease resistance, biodiversity, and overall resilience (Correct answer)
- Simpler harvest logistics and mechanization
- Faster growth of individual crop species
- Lower initial planting cost
Correct answer: Greater pest and disease resistance, biodiversity, and overall resilience
Polycultures mimic natural ecosystems by mixing species, which disrupts pest cycles, supports beneficial insects, and reduces the risk of total crop failure.
Question 6: What does 'chop-and-drop' mulching mean in a food forest context?
- Cutting plant material and leaving it on the soil surface as mulch (Correct answer)
- Harvesting timber and composting it off-site
- Mowing between rows and removing clippings
- Pruning canopy trees and burning the debris
Correct answer: Cutting plant material and leaving it on the soil surface as mulch
Chop-and-drop involves cutting back fast-growing plants like comfrey or pigeon pea and leaving the biomass on the soil to decompose and feed the system.
PDC PDC Food Forest & Agroforestry Systems 2
What is the vine layer's main function in a seven-layer food forest?