Remove surface soil/sediment: brackish/salt marshes

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • One study evaluated the effects, on vegetation, of removing surface soil/sediment to restore or create brackish/salt marshes. The study was in the Netherlands.

VEGETATION COMMUNITY                             

  • Overall richness/diversity (1 study): One study in the Netherlands reported that 23 plant species colonized over two years after stripping topsoil from coastal farmland.


  • Individual species abundance (1 study): One study in the Netherlands reported the frequency of plant species that colonized over two years after stripping topsoil from coastal farmland.


About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A study in 1997–1999 aiming to create a brackish marsh on coastal farmland in the Netherlands (Bakker et al. 2002) reported that an area from which topsoil was removed was colonized by farmland weeds and some plant species characteristic of brackish marshes. Two years after topsoil removal, 23 plant species were recorded in the study area. The most abundant taxa were mostly farmland weeds/generalists, such as chamomile Matricaria recutita (in 97% of quadrats), sow thistle Sonchus oleraceus (76%) and meadow grass Poa annua (61%). Taxa characteristic of brackish marshes included rushes Juncus spp. (in 97% of quadrats), sea aster Aster tripolium (7%) and alkali bulrush Scirpus maritimus (5%). The study does not define a full list of characteristic species. Methods: In 1997, a 30 cm layer of topsoil was stripped from an area of coastal farmland (Emmapolder). Not all topsoil was completely removed from the site: some was stored in rows on site, and so provided a source of farmland weed seeds. Brackish groundwater naturally seeped towards the ground surface. In 1999, vegetation was surveyed in an unplanted area of the site, next to a pool (100 quadrats, each 0.4 m2).

    Study and other actions tested
Please cite as:

Taylor N.G., Grillas P., Smith R.K. & Sutherland W.J. (2021) Marsh and Swamp Conservation: Global Evidence for the Effects of Interventions to Conserve Marsh and Swamp Vegetation. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Marsh and Swamp Conservation

This Action forms part of the Action Synopsis:

Marsh and Swamp Conservation
Marsh and Swamp Conservation

Marsh and Swamp Conservation - Published 2021

Marsh and Swamp Synopsis

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