CWD Wetland Functions & Values 2 — Questions and Answers
Question 1: The Wetland Rapid Assessment Procedure (WRAP) is primarily designed to:
- Determine regulatory jurisdiction under the Clean Water Act
- Provide a rapid estimate of relative wetland functional capacity for planning purposes (Correct answer)
- Classify wetland vegetation communities for ecological restoration projects
- Establish compensatory mitigation ratios for Section 404 permits
Correct answer: Provide a rapid estimate of relative wetland functional capacity for planning purposes
WRAP provides a rapid, cost-effective method for estimating wetland functional capacity relative to a reference standard, making it useful for landscape-level planning and screening assessments.
Question 2: Phosphorus retention in wetland soils occurs primarily through which mechanism?
- Denitrification by anaerobic bacteria
- Adsorption and precipitation with iron, aluminum, and calcium compounds in sediments (Correct answer)
- Volatilization into the atmosphere as phosphine gas
- Exclusive biological uptake by emergent macrophyte roots
Correct answer: Adsorption and precipitation with iron, aluminum, and calcium compounds in sediments
Phosphorus is retained in wetland soils primarily through adsorption onto iron and aluminum oxides and precipitation with calcium, making soil chemistry the dominant long-term phosphorus sink.
Question 3: Which economic valuation method estimates wetland value by surveying what people are willing to pay to preserve a wetland's services?
- Market price method
- Replacement cost method
- Contingent valuation method (Correct answer)
- Travel cost method
Correct answer: Contingent valuation method
Contingent valuation uses structured surveys to elicit willingness-to-pay for wetland services, allowing economists to estimate non-market values for ecological goods that lack direct market prices.
Question 4: Tidal salt marshes and mangrove systems typically exhibit the highest net primary production among wetland types primarily because:
- They have the longest hydroperiod of any wetland type
- Regular tidal flushing delivers nutrient-rich water that promotes high plant growth rates (Correct answer)
- They are geographically isolated from human disturbance allowing unimpeded growth
- Saline conditions eliminate herbivore pressure on vegetation
Correct answer: Regular tidal flushing delivers nutrient-rich water that promotes high plant growth rates
Tidal flushing continuously delivers dissolved nutrients and removes metabolic waste products, creating highly productive conditions that drive the exceptional primary production rates of coastal wetlands.
Question 5: Hydroperiod most directly affects wetland functional processes by controlling:
- The regulatory boundaries used for jurisdictional wetland determination
- The duration and frequency of anaerobic soil conditions that drive biogeochemical cycling (Correct answer)
- The species of trees permitted to grow in a forested wetland
- The amount of compensatory mitigation required for permitted wetland fill
Correct answer: The duration and frequency of anaerobic soil conditions that drive biogeochemical cycling
Hydroperiod determines how long soils remain saturated and anaerobic, which controls the rates of denitrification, methanogenesis, phosphorus cycling, and other biogeochemical processes that define wetland function.
Question 6: Sediment trapping efficiency in a wetland is greatest when:
- Water velocity is high and vegetation is sparse, concentrating deposition in channels
- Water flow is slow and vegetation density is high, promoting particle settling (Correct answer)
- The wetland is deeply flooded year-round to allow continuous particle suspension
- Sediment load consists exclusively of very fine clay particles
Correct answer: Water flow is slow and vegetation density is high, promoting particle settling
Slow velocity reduces the transport energy for particles while dense vegetation increases surface area for particles to contact and settle, maximizing sediment retention.
Question 7: Which wetland functional assessment approach assigns a Functional Capacity Index (FCI) score from 0 to 1 based on comparisons to reference wetlands of the same class?
- Wetland Rapid Assessment Procedure (WRAP)
- Hydrogeomorphic (HGM) functional assessment approach (Correct answer)
- Index of Biotic Integrity (IBI)
- Floristic Quality Assessment (FQA)
Correct answer: Hydrogeomorphic (HGM) functional assessment approach
The HGM approach produces Functional Capacity Index scores scaled from 0 (no function) to 1 (reference standard condition), enabling quantitative comparison of wetland functional capacity across sites.
CWD Wetland Functions & Values 2
The Wetland Rapid Assessment Procedure (WRAP) is primarily designed to: