TABLE 2–1 Summary of Results from Study of a Created Salt Marsh Constructed as a Mitigation Site in North Carolina (1991)

Comparison of Finfish in a Constructed Wetland

Compared with Two Reference Sites

Months to Reach Reference Site Conditions

Trend After Equivalency First Reached

Number of organisms

Trawl

8

Falling

Wegener Ring

28

Rising

Number of species

Trawl

18

Stable

Wegener Ring

43

?

Species similarity

Trawl

0–12

Declining

Wegener Ring

0–12

Declining

SOURCE: Adapted from Rulifson (1991).

agement action but then continued to change. In other words, the equilibrium was obtained but not equivalency (see Table 2–1). Zedler (1990) noted that the average number of individual fish species and the average number of individuals caught at a single reference site and a wetland creation project in Southern California were reached within 5 years. However, the similarities of fish and benthic species between the reference site and mitigation sites were only 58% and 54%, respectively.

Results from a variety of trajectory analyses of soil, plant, and animal communities for mitigation sites are given in Appendix C and summarized in Table 2–2. Plant cover and biomass for some marshes may reach

TABLE 2–2 Time Toward Equivalency for Soil, Plant, and Animal Components in Wetland Restoration Projects Compared with That of Natural Reference Wetlands

Structural Component

Number of Sites

Range (years)

Soils

17

>3 to >30

Wetland plants

Cover or biomass

7

3 to >20, or never

Species composition

3

>5 to >10, or never

Below-ground biomass

2

10+, or never

Fish and fisheries

9

>2 to 10

Marsh fisheries

14

1 to >17, or never

Birds

7

<3 to >15, or never



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