CWD Vegetation Analysis & Plant Identification 2 — Questions and Answers
Question 1: Which plant community indicator is used to assess hydrophytic vegetation when dominant species are facultative (FAC)?
- Prevalence Index (Correct answer)
- Dominance Test
- Rapid Test
- Morphological Adaptation Index
Correct answer: Prevalence Index
The Prevalence Index calculates a weighted average of wetland indicator statuses to determine if the plant community is hydrophytic when dominants are FAC.
Question 2: What wetland indicator status applies to plants that almost always occur in wetlands (>99% of the time)?
- OBL (Obligate Wetland) (Correct answer)
- FACW (Facultative Wetland)
- FAC (Facultative)
- UPL (Upland)
Correct answer: OBL (Obligate Wetland)
OBL (Obligate Wetland) species occur in wetlands more than 99% of the time under natural conditions.
Question 3: Which of the following is a morphological adaptation to wetland conditions in herbaceous plants?
- Aerenchyma tissue in stems and roots (Correct answer)
- Thick waxy cuticle on leaves
- Deep taproot systems
- Reduced leaf surface area
Correct answer: Aerenchyma tissue in stems and roots
Aerenchyma is specialized spongy tissue with large air spaces that facilitates oxygen transport to roots in anaerobic saturated soils.
Question 4: Under the 1987 Corps of Engineers Wetland Delineation Manual, what percentage of dominant species must be OBL, FACW, or FAC to satisfy the hydrophytic vegetation criterion?
- More than 50% (Correct answer)
- At least 75%
- At least 90%
- 100%
Correct answer: More than 50%
The Dominance Test requires that more than 50% of the dominant species in each stratum are OBL, FACW, or FAC.
Question 5: Typha latifolia (broadleaf cattail) has which wetland indicator status?
- OBL (Correct answer)
- FACW
- FAC
- FACU
Correct answer: OBL
Typha latifolia is classified as OBL because it occurs almost exclusively in wetland environments.
Question 6: What is the correct method for determining dominant species in a forested wetland stratum?
- The 50/20 rule based on relative basal area and relative density (Correct answer)
- Simple count of the most abundant tree species
- Selecting species with the largest individual trunk diameter
- Identifying species with the highest canopy cover percentage only
Correct answer: The 50/20 rule based on relative basal area and relative density
The 50/20 rule ranks species by importance value (relative basal area + relative density) and selects those needed to reach 50% cumulative importance, plus any species >20%.
Question 7: Which plant exhibits pneumatophores as an adaptation to flooded conditions?
- Taxodium distichum (bald cypress) (Correct answer)
- Quercus alba (white oak)
- Pinus strobus (eastern white pine)
- Acer saccharum (sugar maple)
Correct answer: Taxodium distichum (bald cypress)
Bald cypress produces pneumatophores (cypress knees) that are woody projections rising from roots, believed to facilitate gas exchange in anaerobic soils.
CWD Vegetation Analysis & Plant Identification 2
Which plant community indicator is used to assess hydrophytic vegetation when dominant species are facultative (FAC)?