Vegetation development in created, restored, and enhanced mitigation wetland banks of the United States

  • Published source details Spieles D.J. (2005) Vegetation development in created, restored, and enhanced mitigation wetland banks of the United States. Wetlands, 25, 51-63.


This study is summarised as evidence for the following.

Action Category

Restore/create freshwater marshes or swamps (specific action unclear)

Action Link
Marsh and Swamp Conservation
  1. Restore/create freshwater marshes or swamps (specific action unclear)

    A replicated study in the early 2000s of 45 created, restored and enhanced freshwater wetlands in the USA (Spieles 2005) reported that they typically contained wetland vegetation after 1–7 years. In 43 of the 45 studied wetlands, the overall plant community was more characteristic of wetlands than uplands. The other two wetlands contained vegetation that was marginally more characteristic of uplands than wetlands (data reported as a wetland indicator index). On average, the wetlands contained 11 plant species/10 m2 (range: 0.2–56 species/10 m2), of which 16% were not native (range: 0–53%). The study also reported effects of intervention type (creation, restoration or enhancement), wetland setting (depressional, riverine or lakeshore) and wetland age on these metrics, and reported data on the frequency of some individual plant species (see original paper). Methods: Data on vascular plant species and cover were collected from monitoring reports for 45 wetlands (within 36 project areas across 21 states). The wetlands were 1–562 ha in area and 1–7 years old. Of the 45 wetlands, 17 had been created (from scratch), 19 restored (from degraded wetlands) and nine enhanced (increasing value of existing wetlands) as part of mitigation projects. Thirty-two wetlands contained areas of marsh and 19 contained areas of shrubby/forested swamp. The study does not consistently separate results for marsh and swamp vegetation.

    (Summarised by: Nigel Taylor)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust