SAF Ecosystem Restoration 3 — Questions and Answers
Question 1: Which soil amendment is MOST appropriate for restoring nitrogen-limited forest soils without creating long-term nutrient imbalances?
- High-rate synthetic nitrogen fertilizer
- Mycorrhizal inoculant only
- Biosolids at agronomic rates
- Nitrogen-fixing cover crop incorporation (Correct answer)
Correct answer: Nitrogen-fixing cover crop incorporation
Nitrogen-fixing cover crops add biologically available nitrogen gradually through mineralization, avoiding pulse loading that can cause leaching or unwanted species shifts.
Question 2: In the SAF framework, what distinguishes 'ecological restoration' from 'ecological rehabilitation'?
- Restoration is cheaper and faster than rehabilitation
- Restoration aims to return an ecosystem to its pre-disturbance state while rehabilitation focuses on recovering key functions without full species recovery (Correct answer)
- Rehabilitation requires more species diversity than restoration
- Restoration applies only to forests while rehabilitation applies to wetlands
Correct answer: Restoration aims to return an ecosystem to its pre-disturbance state while rehabilitation focuses on recovering key functions without full species recovery
Restoration targets return to historical structure and composition, whereas rehabilitation focuses on restoring ecosystem functions and services without necessarily recovering all original species.
Question 3: Which monitoring metric BEST indicates successful mycorrhizal network re-establishment in a restored forest?
- Above-ground biomass accumulation rate
- Seedling root colonization percentage by ectomycorrhizal fungi (Correct answer)
- Canopy closure percentage
- Litter depth accumulation
Correct answer: Seedling root colonization percentage by ectomycorrhizal fungi
Root colonization percentage directly measures whether mycorrhizal fungi have formed functional associations with plant roots, indicating network re-establishment.
Question 4: A restoration practitioner discovers that a target site has a persistent soil seed bank of invasive plants. The BEST integrated management strategy would be:
- Immediate broadcast seeding of native species to out-compete invaders
- Repeated disturbance cycles (tillage) to deplete the seed bank before native planting (Correct answer)
- Apply herbicide once then plant natives immediately
- Fence the site and allow natural succession
Correct answer: Repeated disturbance cycles (tillage) to deplete the seed bank before native planting
Repeated disturbance cycles stimulate germination of invasive seeds and allow removal before they reset the bank, progressively depleting it prior to native establishment.
Question 5: What is the primary ecological function of coarse woody debris (CWD) in forest restoration?
- Increasing fire risk for future prescribed burns
- Providing carbon storage, habitat structure, and substrate for decomposers and seedlings (Correct answer)
- Reducing understory plant diversity
- Blocking wildlife movement corridors
Correct answer: Providing carbon storage, habitat structure, and substrate for decomposers and seedlings
CWD serves as carbon storage, supports decomposer communities, provides microhabitat for wildlife, and creates seedbed substrate essential to forest regeneration.
Question 6: The 'intermediate disturbance hypothesis' is applied in restoration ecology to suggest that:
- All disturbances are harmful and should be prevented
- Moderate disturbance frequency and intensity maximizes species diversity (Correct answer)
- Only high-intensity disturbances promote native species recovery
- Disturbance timing is irrelevant to restoration outcomes
Correct answer: Moderate disturbance frequency and intensity maximizes species diversity
The intermediate disturbance hypothesis proposes that moderate, periodic disturbances prevent competitive exclusion and maintain higher species diversity than either very frequent or very rare disturbances.
Question 7: When designing a seed mix for dry ponderosa pine restoration in the U.S. Southwest, which criterion should take HIGHEST priority?
- Lowest cost per pound
- Broadest geographic origin to maximize genetic diversity
- Local provenance within the same seed zone to ensure climatic adaptation (Correct answer)
- Fastest germination rate regardless of origin
Correct answer: Local provenance within the same seed zone to ensure climatic adaptation
Local provenance seed is best adapted to regional climate, soils, and disturbance regimes, maximizing establishment success and long-term persistence in the restored ecosystem.
SAF Ecosystem Restoration 3
Which soil amendment is MOST appropriate for restoring nitrogen-limited forest soils without creating long-term nutrient imbalances?