The hemiparasite Pedicularis palustris: 'ecosystem engineer' for fen-meadow restoration

  • Published source details Decleer K., Bonte D. & Van Diggelen R. (2013) The hemiparasite Pedicularis palustris: 'ecosystem engineer' for fen-meadow restoration. Journal for Nature Conservation, 21, 65-71.


This study is summarised as evidence for the following.

Action Category

Introduce an organism to control problematic plants

Action Link
Peatland Conservation

Sow seeds of parasitic species (e.g. yellow rattle)

Action Link
Grassland Conservation
  1. Introduce an organism to control problematic plants

    A controlled, before-and-after study in 1994–2012 in a degraded fen meadow in Belgium (Decleer er al. 2013) found that a plot sown with parasitic marsh lousewort Pedicularis palustris developed a different plant community to unsown plots, less dominated by acute sedge Carex acuta, and with greater moss cover and more plant species. After six years, plots with and without lousewort contained a significantly different overall plant community (reported as a statistical model result). The plot with lousewort contained less acute sedge than the plot without lousewort: less biomass (80 vs 540 g/m2), shorter plants (100 vs 40 cm) and less cover (after 18 years; 20 vs 80%). After six years, the plot with lousewort also contained less overall plant biomass (460 vs 670 g/m2), but greater moss cover (49 vs 6%) and more plant species (21 vs 14 species/400 m2). Before intervention, vegetation was similar in both plots (acute sedge biomass: 870 g/m2; acute sedge cover: 100%; overall plant biomass: 960 g/m2; other data not reported). In July 1994, one 20 x 20 m plot dominated by acute sedge was sown with 500 lousewort seeds. An adjacent plot was not sown and lousewort plants were continually removed. Biannual mowing had been resumed in 1992. Data were recorded in each plot in 1994, 2000 and 2012: height of 30 random sedge plants, dry above-ground biomass from six 1 m2 quadrats, and plant species and moss cover in ten 1 m2 quadrats.

    (Summarised by: Nigel Taylor)

  2. Sow seeds of parasitic species (e.g. yellow rattle)

    A controlled study in 1994–2000 in a degraded fen meadow in Oostkamp, Belgium (Decleer et al. 2013) found that sowing seeds of the parasitic plant marsh lousewort Pedicularis palustris increased overall plant species richness and the abundance of six target plant species. After six years, the average number of plant species was higher in the site where lousewort seeds were sown (21 species/quadrat) than the site where no lousewort seeds were sown (14 species/quadrat). The site sown with lousewort also had a greater abundance of six target plant species (45–191 plants/10 m2) than the unsown site (2–74 plants/10 m2; see original paper for details). In July 1994, two adjacent sites measuring 20 x 20 m were established in a fen meadow dominated by acute sedge Carex acuta. Marsh lousewort was sown in one site (500 seeds), whereas no seeds were sown in the other. Both sites were mowed 1–2 times/year. Marsh lousewort detected in the unsown site was manually removed. In July 2000, vegetation was surveyed within 10 randomly selected 1-m2 quadrats/site.


    (Summarised by: Anna Berthinussen)

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