Background information and definitions
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 waders and other biodiversity. The studies below describe instances where multiple interventions have been used to maintain meadows. When the effects of multiple interventions, such as raising water levels and adding foot drains, can be separated, they are discussed under the relevant interventions in ‘Threat: Natural system modifications’. The creation of new water meadows and the restoration of degraded ones are discussed in ‘Habitat restoration and creation’.
Supporting evidence from individual studies
A replicated study in 19 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. This study is also discussed in ‘Pay farmers to cover the costs of conservation measures’ and ‘Legally protect habitats’.Study and other actions tested
A replicated, before-and-after site comparison study 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 lapwing 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. 17 pairs of fields were matched for landscape structure and were surveyed in 1989, 1992 and 1995.Study and other actions tested
A 2006 replicated site comparison study of 42 fields in the Netherlands in 2006 (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 didn’t differ between agri-environment schemes 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 replicated study in 2010 on four areas of wet grassland managed for wildlife in Kent, England (Merricks 2010), found that productivity of northern lapwings Vanellus vanellus was too low to sustain populations on three of the four (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 fertiliser 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