Pay stakeholders to protect marshes or swamps

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

Study locations

Key messages

  • Two studies evaluated the overall effects, on vegetation or human behaviour, of paying stakeholders to protect marshes or swamps. There was one study in each of the UK and Nigeria.


  • Overall extent (1 study): One replicated, before-and-after, site comparison study in the UK found that paying landowners to manage farmland ditches under agri-environment rules had no clear or significant effect on the frequency of emergent vegetation.
  • Overall richness/diversity (1 study): One replicated, site comparison study in the UK found that farmland ditches managed under agri-environment rules contained a similar number of plant species to ditches not managed under these rules.






  • Human behaviour (1 study): One study in Nigeria reported that 58 communities with access to micro-credits for sustainable development changed their behaviour. In particular, they switched from livelihood practices that damaged mangrove forests to more sustainable practices.

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, before-and-after, site comparison study in 2005–2012 of farmland ditches in England, UK (FERA 2013) found that managing ditches under an agri-environment scheme had no significant effect on the frequency of emergent vegetation or total plant species richness. After six years, 48–55% of ditches managed under agri-environment rules contained emergent vegetation. There were 6.1–6.5 plant species/ditch (emergent, aquatic and terrestrial combined). These values did not significantly differ from ditches not managed under agri-environment rules: 62% contained emergent vegetation and there were 6.4 plant species/ditch. Additionally, there was no change over time in the proportion of managed ditches that contained emergent vegetation: 39% just before or just after the agri-environment scheme began, then 34% five years later (statistical significance not assessed). Methods: The “Entry Level Stewardship” agri-environment scheme began in 2005/2006. Rules for ditch management included leaving half of the ditch banks uncut every year, and not cultivating within 2 m of the ditch centre. Vegetation in and along ditches was surveyed in 2005/2006, 2011 and 2012. Surveys included 52–170 ditches/year managed under agri-environment rules, and 16–17 ditches/year on farms not participating in the scheme.

    Study and other actions tested
  2. A study in 2008–2016 in Nigeria (Wetlands International 2016) reported that paying community groups to use wetlands sustainably changed their behaviour. Fifty-eight community groups provided with access to micro-credits for sustainable development stopped practices that damaged mangrove forests (mainly cutting mangrove trees). They switched to practices less damaging to mangrove forests (such as fish and periwinkle farming) and contributed to wetland restoration. Methods: The payment scheme was implemented within the Bio-Rights framework. The study does not provide further details of the scheme, or quantify the behavioural changes.

    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

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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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