Maintain traditional water meadows (includes management for breeding and/or wintering waders/waterfowl)
Overall effectiveness category Likely to be beneficial
Number of studies: 8
Background information and definitions
This intervention may involve using management such as mowing or grazing to maintain plant communities and wildlife typically associated with traditional water meadows. Water meadows are areas of grazing land or hay meadow that have carefully controlled water levels to keep the soil damp. In Europe they provide valuable breeding habitats for wading birds and other biodiversity.
In the Netherlands, the ‘meadow bird agreements’ agri-environment scheme is designed to protect birds associated with wet meadows (Kleijn & van Zuijlen 2004). Fields managed under ‘meadow bird agreements’ must not have any agricultural activities from 1 April to June-July, pesticide use is prohibited as is cultivation and re-seeding, the areas must be mown or grazed at least once a year and water levels must be maintained (Kleijn & van Zuijlen 2004).
See also ‘Restore or create traditional water meadows’ for studies that look at the effects of creating or restoring water meadows.
Supporting evidence from individual studies
A randomized, replicated, controlled trial in 1972-1979 on a wet Arrhenatherion elatioris grassland site in the Netherlands (Oomes & Mooi 1981) found that cutting in June, with or without a second cut in September, maintained a relatively stable vegetation. Cutting once in August had a similar effect, but is expected in the long run to produce denser vegetation with a loss of some species. Cutting in May, May and September, or June increased the number of plant species from 52/plot (at the beginning of the experiment) to 55/plot after eight years. Never cutting, or cutting every other June, were the only treatments to reduce species richness, to 38 and 49 species/plot, respectively. Fertilizer treatments (NPK: nitrogen, phosphorous, potassium) (50:20:20 kg NPK/ha and 50 kg N/ha, with a June cut) led to dominance by a few species but did not reduce species richness. The Arrhenatherion elatioris grassland included false oat grass Arrhenatherum elatius, cock’s foot Dactylis glomerata and Queen Anne’s lace Daucus carota. Treatments were replicated four times in 100 m2 plots. Plants were surveyed each May in 50 quadrats/plot of 25 cm2 for monocotyledons (mainly grasses) and 400 cm2 for dicotyledons (broadleaved plants).Study and other actions tested
A replicated study in 19 lowland wet grassland nature reserves established across England between 1983 and 1999 (Ausden & Hirons 2002) found that the number of northern lapwing Vanellus vanellus and common redshank Tringa totanus on 13 nature reserves increased by 300% and 500% respectively in the first seven years following the initiation of management aimed at wading birds. Numbers then declined but were still higher than before the initiation of management. However, across all reserves, common snipe Gallinago gallinago declined, largely due to population collapses on reserves with mineral soils. Management included immediate changes to grazing (reduced during breeding seasons and adjusted to produce a favourable sward) and mowing (delayed until after nesting) and hydrological changes (raising water levels, surface flooding) introduced over two or more years.Study and other actions tested
A replicated, site comparison study of 16 paired (adjacent) grazed and mown fens in southern Germany (Stammel et al. 2003) found that plant species richness was significantly higher in mown compared to grazed sites, but the percentage of typical fen species or Red Data Book species did not differ. Mown sites had 206 species (50/25 m² plot) compared to 195 (43/25 m² plot) in grazed sites. Numbers of typical fen species (18-19/25 m² plot) and Red Data Book species (6-7/25 m² plot) were similar. Species tended to differ in frequency and abundance in the two treatments. Grazing favoured grasses (35 vs 29%), small plants and meadow plants (55 vs 49%) which were taller. Tree and moss species did not differ (2% and 14-15% respectively). Vegetation height and above-ground biomass did not differ between treatments, whereas species traits tended to differ in their response to management. More indicator species of wet soil conditions and species adapted to flooding were found on pasture. Sites were mown from September or moderately grazed (< 0.5 young cattle/ha) from May-October; grazing had been continuous for at least ten years. Cover of plant species was sampled in 109 vegetation plots (5 x 5 m), with the number of plots/site depending on fen size. Three biomass samples (25 x 25 cm) were also taken from each site.Study and other actions tested
A site comparison study in 1989, 1992, and 1995 of 34 fields in Zeeland, the Netherlands (Kleijn & van Zuijlen 2004) found no conclusive evidence that meadow bird conservation efforts resulted in higher territory numbers. Although there were significantly more meadow birds and territories of northern lapwing Vanellus vanellus and black-tailed godwit Limosa limosa on fields managed for meadow bird conservation than on conventionally farmed fields in 1995, these differences were at least partly because those meadows in the bird agreements scheme also had higher groundwater levels. Moreover, population trends between 1989 and 1995 were similar for fields with and without meadow bird agreements, and the observed difference in settlement density in 1995 was also already present in 1989. Seventeen pairs of fields were matched for landscape structure and were surveyed in 1989, 1992 and 1995.Study and other actions tested
A replicated site comparison study of 42 fields in the Netherlands (Kleijn et al. 2006) found that more birds bred on 12.5 ha scheme plots consisting of a mixture of fields with postponed agricultural activities and fields with a per-clutch payment scheme than on conventionally farmed plots. A survey of individual fields found there was no difference in bird abundance and breeding on those fields with postponed agricultural activities only and on conventionally farmed fields. The number of bird species on each type of farmland also did not differ between agri-environment scheme and non-agri-environment scheme plots. The agri-environment scheme, which intended to promote the conservation of Dutch meadow birds, prohibited changes in field drainage, pesticide application (except for patch-wise control of problem weeds) and any agricultural activity between 1 April and early June. Additionally, farmers of surrounding fields were paid for each meadow bird clutch laid on their land (though no agricultural restrictions were in place on these fields). The study surveyed seven pairs of fields (one within the agri-environment scheme, one conventionally farmed) and the 12.5 ha area surrounding each field, from each of three different parts of the Netherlands four times during the breeding season.Study and other actions tested
Referenced paperKleijn D., Baquero R.A., Clough Y., Diaz M., De Esteban J., Fernandez F., Gabriel D., Herzog F., Holzschuh A., Johl R., Knop E., Kruess A., Marshall E.J.P., Steffan-Dewenter I., Tscharntke T., Verhulst J., West T.M. & Yela J.L. (2006) Mixed biodiversity benefits of agri-environment schemes in five European countries. Ecology Letters, 9, 243-254
A 2006 review (Middleton et al. 2006) describes eight studies on the impact of cattle-grazing or mowing on wet meadows (or sedge or fen meadows) in Europe. Impacts of grazing were mixed. One study found that the abundance of small mammals in wet meadows was increased by cattle grazing at intermediate intensities (around 0.5 cattle/ha) and reduced by much higher or lower stocking densities (Schmidt et al. 2005). Another study found that reintroducing cattle in a mosaic landscape with wet sedge meadows and drier grasslands reduced species richness, as the dry sites were overgrazed and the wet sites were avoided and remained ungrazed (Bakker & Grootjans 1991). The review describes six studies that looked at the impact of mowing. Four studies found that hand mowing could be used to maintain sedge/water meadows (or fens) (Hansson & Fogelfors 2000, Øien & Moen 2001, Mitlacher et al. 2002, Billeter et al. 2003) and another found that re-instating mowing increased the population of the fen-orchid Nigritella nigra (Moen & Øien 2002). One study found that mowing resulted in higher species richness than grazing on an abandoned fen meadow (Hald & Vinther 2000), while another found that mowing only increased species richness if the species were part of the standing crop, in the seed bank or could disperse to the site (Billeter et al. 2003).
Bakker J.P. & Grootjans A.P. (1991) Potential for vegetation regeneration in the middle course of the Drentsche Aa brook valley (The Netherlands). Verhandlungen der Gesellschaft für Ökologie, 20, 249-263.
Hansson M. & Fogelfors H. (2000) Management of a seminatural grassland: results from a 15-year-old experiment in southern Sweden. Journal of Vegetation Science, 11, 31-38.
Hald A.B. & Vinther E. (2000) Restoration of a species-rich fen-meadow after abandonment: response of 64 species to management. Applied Vegetation Science, 3, 15-25.
Øien D.-I. & Moen A. (2001) Nutrient limitation in boreal plant communities and species influenced by scything. Applied Vegetation Science, 4, 197-207.
Mitlacher K., Poschlod P., Rosén E. & Bakker J.P. (2002) Restoration of wooded meadows: a comparative analysis along a chronosequence on Öland (Sweden). Applied Vegetation Science, 5, 63-73.
Moen A. & Øien D.-I. (2002) Ecology and survival of Nigritella nigra, a threatened orchid species in Scandinavia. Nordic Journal of Botany, 22, 435-461.
Billeter R.D., Hooftman A.P. & Diemer M. (2003) Differential and reversible responses of common fen meadow species to abandonment. Applied Vegetation Science, 6, 3-12.
Schmidt N.M., Olsen H., Bildsøe M., Sluydts V. & Leirs H. (2005) Effects of grazing intensity on small mammal population ecology in wet meadows. Basic Applied Ecology, 6, 57-66.Study and other actions tested
A study of two floodplain meadows in adjacent nature reserves on former natural floodplains of the River Demer, Belgium (Gerard et al. 2008) found that mowing and flooding meadows resulted in increased plant diversity. Mown, frequently flooded plots had higher plant species richness (average 16 species/plot) than non-mown, frequently flooded (10 species) or mown, infrequently flooded (12 species) plots. Mown sites had higher numbers of smaller species, non-mown sites had more tall grasses. Average standing crop (range: 492-654g/m²/year) was significantly lower in mown sites compared to non-mown sites. Overall, there was a significant negative correlation between species richness and standing crop. Data were obtained from two reserves: one frequently flooded (150 ha; flooded at least once a year for 5-50 days) and one (600 ha) in which part is infrequently inundated (about once every 5 years). In each reserve, 10 plots (2 x 2 m) were randomly selected in annually June-mown fields, and five in non-mown fields. Plant species composition was recorded in each in early July 2005 and standing biomass mid-end of July.Study and other actions tested
A replicated study in 2010 on four areas of wet grassland managed for wildlife in Kent, England (Merricks 2010) found that productivity of northern lapwing Vanellus vanellus was too low to sustain populations on three of the four areas (i.e. below 0.7 chicks/pair/year, which is thought to be the level necessary to maintain populations). The author identifies five management practices thought to be important for lapwing success: grazing regime, water availability, ‘micro-topography’ (changes in ground level to provide a range of habitats), reduced fertilizer inputs and predator control. At least one of these was rated as ‘fair’ or ‘poor’ in all three sites with low productivity.Study and other actions tested