B.F. Bachelor of Forestry Bachelor of Forestry Forest Ecosystem 3 — Questions and Answers
Question 1: Which ecological concept describes the maximum population size that a forest ecosystem can sustainably support?
- Niche breadth
- Carrying capacity (Correct answer)
- Ecological footprint
- Resilience threshold
Correct answer: Carrying capacity
Carrying capacity (K) represents the upper limit of population size that available resources can sustain over time.
Question 2: A forest manager notices that soil respiration rates spike sharply after a summer rainstorm following drought. This phenomenon is called:
- Frost heaving
- Petrichor release
- The Birch effect (Correct answer)
- Priming effect
Correct answer: The Birch effect
The Birch effect is the pulse of CO2 released when dry soils are rewetted, due to sudden microbial activity.
Question 3: In which forest zone does photosynthesis typically exceed respiration on an annual basis, making it a net carbon sink?
- Subalpine krummholz zone
- Mature old-growth temperate forest
- Early post-fire pioneer stage
- Young aggrading second-growth forest (Correct answer)
Correct answer: Young aggrading second-growth forest
Young aggrading forests rapidly accumulate biomass, so net ecosystem production (NEP) is strongly positive.
Question 4: What role do woodpeckers play in forest ecosystem function beyond foraging for insects?
- They disperse mycorrhizal spores
- They create cavity habitat used by secondary nesters (Correct answer)
- They accelerate nutrient cycling in soil
- They reduce bark beetle outbreaks through direct predation alone
Correct answer: They create cavity habitat used by secondary nesters
Woodpecker-excavated cavities are used by owls, ducks, bats, and other secondary cavity nesters, increasing biodiversity.
Question 5: Which term describes the functional role of a species within its ecosystem, including its resource use and interactions?
- Guild
- Niche (Correct answer)
- Biome
- Ecotone
Correct answer: Niche
An ecological niche encompasses all biotic and abiotic conditions a species requires and its functional role.
Question 6: Allelopathy in forest ecosystems refers to:
- Mutualistic nutrient exchange between tree roots
- Chemical inhibition of neighboring plants by a species (Correct answer)
- The vertical stratification of vegetation layers
- Symbiotic nitrogen fixation by root bacteria
Correct answer: Chemical inhibition of neighboring plants by a species
Allelopathy occurs when plants release phytotoxic chemicals that suppress germination or growth of competitors.
Question 7: In forest ecology, the term 'snag' refers to:
- A dense shrub thicket impeding regeneration
- A standing dead or dying tree (Correct answer)
- A seed caught in a rock crevice
- A low-lying area prone to flooding
Correct answer: A standing dead or dying tree
Snags are standing dead trees that provide critical habitat for cavity-nesting birds, bats, and invertebrates.
B.F. Bachelor of Forestry Bachelor of Forestry Forest Ecosystem 3
Which ecological concept describes the maximum population size that a forest ecosystem can sustainably support?