Abandon mined land: allow brackish/saline marshes or swamps to recover without active intervention

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

Study locations

Key messages

  • One study evaluated the effects, on vegetation, of abandoning formerly mined land with the expectation that brackish/saline marshes or swamps would recover spontaneously. The study was in France.


  • Community types (1 study): One replicated study in France simply classified the plant community types that developed on abandoned salt pans. Areas flooded for at least part of the year developed salt marsh plant communities, with the exact community composition depending on the duration of flooding and soil salinity.




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 replicated study in 1990 of 40 abandoned salt pans in northwest France (Bouzillé et al. 2001) reported that they contained a range of plant community types, depending on the duration of flooding and soil salinity. In areas flooded for long periods (>277 days/year on average) and with low soil salinities (<2.5 mS/cm on average), common and/or abundant species included shoreline sedge Carex riparia, yellow flag Iris pseudacorus, branched bur-reed Sparganium erectum and cuckoo flower Cardamine pratensis. In areas flooded for shorter periods (122–132 days/year on average) and with higher soil salinities (3.3–4.3 mS/cm on average), common and/or abundant species included saltmarsh rush Juncus gerardii and bulbous foxtail Alopecurus bulbosus. Some areas were never flooded and developed upland plant communities. Community data were reported as a graphical analysis, frequency classes and cover classes. Methods: In May 1990, plant species and their cover were recorded in three quadrats (one low elevation, one medium, one high) in each of 40 abandoned salt pans (no artificial inputs of salt water for 150 years). Some sites were still affected by adjacent drainage ditches. Some grazing and/or mowing had occurred on the sites since abandonment.

    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?

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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

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