B.F. Bachelor of Forestry Bachelor of Forestry Forest Ecosystem 4 — Questions and Answers
Question 1: Which index is most commonly used to quantify species diversity by combining richness and evenness?
- Sorenson similarity index
- Shannon-Wiener index (H') (Correct answer)
- Morisita-Horn index
- Basal area index
Correct answer: Shannon-Wiener index (H')
The Shannon-Wiener index accounts for both the number of species and the evenness of their relative abundances.
Question 2: Forest fragmentation most directly threatens wildlife populations through which mechanism?
- Increased soil erosion rates
- Edge effects and reduced interior habitat (Correct answer)
- Higher precipitation interception
- Decreased litter decomposition
Correct answer: Edge effects and reduced interior habitat
Fragmentation creates disproportionate edge habitat and reduces interior forest, harming interior-obligate species.
Question 3: Which nutrient is most commonly the primary limiting factor for tree growth in boreal forest ecosystems?
- Phosphorus
- Potassium
- Nitrogen (Correct answer)
- Calcium
Correct answer: Nitrogen
Cold temperatures slow decomposition and nitrogen mineralization, making N the key growth-limiting nutrient in boreal forests.
Question 4: What is the ecological function of coarse woody debris (CWD) on a forest floor?
- It prevents seed germination of pioneer species
- It serves as habitat, moisture reservoir, and nutrient pool (Correct answer)
- It reflects solar radiation to cool the understory
- It primarily functions as a fire accelerant
Correct answer: It serves as habitat, moisture reservoir, and nutrient pool
CWD supports salamanders, invertebrates, fungi, and slow-release nutrients while retaining soil moisture.
Question 5: In a temperate deciduous forest, leaf litter decomposition is fastest under which conditions?
- Cold, dry winters with low fungal activity
- Warm, moist conditions with diverse invertebrate communities (Correct answer)
- High elevation with thin snowpack
- Acidic pH below 4.0 with abundant conifer needles
Correct answer: Warm, moist conditions with diverse invertebrate communities
Warm, moist environments maximize microbial and invertebrate decomposer activity, accelerating litter breakdown.
Question 6: Which silvicultural concept describes the vertical layers of a forest from ground to canopy?
- Horizontal zonation
- Stand stratification (Correct answer)
- Lateral succession
- Canopy closure index
Correct answer: Stand stratification
Stand stratification refers to the distinct vertical layers: ground, herb, shrub, subcanopy, and canopy.
Question 7: A watershed study shows that clear-cutting a forested catchment initially increases streamflow. What is the primary reason?
- Removal of trees eliminates evapotranspiration (Correct answer)
- Logging roads compact soils and increase runoff velocity
- Increased litter decomposition raises water table
- Slash burning creates hydrophobic soil layers
Correct answer: Removal of trees eliminates evapotranspiration
Trees transpire large volumes of water; their removal reduces evapotranspiration, leaving more water to become streamflow.
B.F. Bachelor of Forestry Bachelor of Forestry Forest Ecosystem 4
Which index is most commonly used to quantify species diversity by combining richness and evenness?