PDC PDC Food Forest & Agroforestry Systems 1 — Questions and Answers
Question 1: Which layer is considered the canopy layer in a food forest design?
- Tall fruit and nut trees (Correct answer)
- Shrubs and berry bushes
- Herbaceous plants
- Ground cover plants
Correct answer: Tall fruit and nut trees
The canopy layer consists of tall fruit and nut trees that form the uppermost stratum of a food forest.
Question 2: What is the primary purpose of a nitrogen-fixing tree in a food forest?
- To improve soil fertility through atmospheric nitrogen fixation (Correct answer)
- To provide shade for understory plants
- To attract pollinators
- To act as a windbreak
Correct answer: To improve soil fertility through atmospheric nitrogen fixation
Nitrogen-fixing trees like black locust or alder host root bacteria that convert atmospheric nitrogen into plant-available forms, enriching the soil.
Question 3: In agroforestry, what does the term 'alley cropping' refer to?
- Growing crops in rows between lines of trees or shrubs (Correct answer)
- Planting trees along fence lines
- Intercropping two annual vegetables
- Harvesting crops in sequence by season
Correct answer: Growing crops in rows between lines of trees or shrubs
Alley cropping places rows of trees or shrubs with crops grown in the alleys between them, benefiting from tree shade, leaf mulch, and root interactions.
Question 4: Which of the following best describes 'guild planting' in a food forest?
- A community of mutually beneficial plants grown together around a central species (Correct answer)
- A sequence of plants grown over multiple seasons
- A collection of plants from the same botanical family
- A rotation system that prevents soil depletion
Correct answer: A community of mutually beneficial plants grown together around a central species
A guild is a group of plants selected to support each other through functions like nitrogen fixation, pest deterrence, and pollinator attraction around a central crop tree.
Question 5: What is 'succession' as applied to food forest development?
- The natural progression from pioneer species toward a mature, stable ecosystem (Correct answer)
- Rotating crop varieties each season
- Replacing one tree species with another after harvest
- A legal transfer of land between permaculture designers
Correct answer: The natural progression from pioneer species toward a mature, stable ecosystem
Ecological succession describes how pioneer species modify conditions to allow more complex species to establish, and food forest designers harness this process deliberately.
Question 6: Which root crop is commonly planted as a 'dynamic accumulator' in the ground layer of a food forest?
- Comfrey (Symphytum officinale) (Correct answer)
- Potato
- Garlic
- Beet
Correct answer: Comfrey (Symphytum officinale)
Comfrey has deep tap roots that mine subsoil minerals, and its leaves decompose rapidly to release nutrients on the surface, making it a classic dynamic accumulator.
PDC PDC Food Forest & Agroforestry Systems 1
Which layer is considered the canopy layer in a food forest design?