Individual study: Restoration of grassland and heathland by traditional management works on dry sites but not as well wet sites, in the Netherlands
Bakker J.P. (1994) Nature management in Dutch grasslands. British Grassland Society Occassional Symposium, 28, 115.
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Reduce chemical inputs in grassland management
A 1994 review of methods to restore grasslands in the Netherlands (Bakker 1994) found three experiments in which the plant community became more similar to species-rich, lower nutrient grassland over 20 years, after the cessation of chemical fertilizer input. The location of these experiments is not given, they may be those reported in (Olff & Bakker 1991). Plant species of fertilized, nutrient-rich grasslands (such as perennial rye grass Lolium perenne and broad-leaved dock Rumex obtusifolius) were gradually replaced by species of lower-nutrient grassland (such as red fescue Festuca rubra and sweet vernal grass Anthoxanthum odoratum on two sites). One site had dry sandy soil and two sites had wet peaty soils. Fertilizer applications were stopped in 1972 and hay was cut and removed in July each year. Plants were monitored from 1972 to 1992. The method was not considered as effective on the wet sites. The review briefly described the results of an extensive Dutch study on the effects of grassland management on birds (Dijkstra 1991). The study showed that reducing fertilizer to 200 kg N/ha favours common meadow birds such as northern lapwing Vanellus vanellus, Eurasian oystercatcher Haematopus ostralegus and black-tailed godwit Limosa limosa. Reducing fertilizer to 50 kg N/ha favours common redshank Tringa totanus, common snipe Gallinago gallinago and ruff Philomachus pugnax. Reducing to no fertilizer reduces meadow bird numbers. Data were not given.
Dijkstra H. (1991) Natuur- en landschapsbeheer door landbouwbedrijven : eindverslag van het COAL-onderzoek [Nature and landscape management by agricultural enterprises: final report of the COAL study]. University of Wageningen Monograph. COAL-publikatie report. 60.
Restore or create traditional water meadows
A 1994 review of methods to restore grasslands in the Netherlands (Bakker 1994) reports one experiment in which the plant community on a wet peaty grassland changed away from the desired plant community over 14 years, after cessation of fertilizer input and the introduction of grazing. Characteristic species, such as marsh marigold Caltha palustris, were replaced by tall plants, such as lesser pond sedge Carex acutiformis and reed sweetgrass Glyceria maxima. The restoration was considered unsuccessful. The authors argue that continued agricultural drainage on surrounding areas is responsible for the failure of the restoration, because the water table is not high enough to restore the plant community. Fertilizer applications were stopped in 1971. Plants were monitored from 1978 to 1992. Site location and details were not given.