Individual study: Review of evidence on how to restore species-rich grassland
Diggelen R.V. (2007) Habitat creation: nature conservation of the future? Aspects of Applied Biology, 82, 1-11
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Raise water levels in ditches or grassland
A 2007 review of experimental evidence on how to restore species-rich grassland on old arable fields (Diggelen 2007) found three studies showing that re-wetting soils rich in organic matter works only a little (around 20% less available nitrogen - Oomes 1991, Berendse et al. 1994) or increases nutrients (20% increase in available nitrogen - Eschner & Liste 1995).
Oomes M. J. M. (1991) Effects of groundwater level and the removal of nutrients on the yield of non-fertilized grassland. Acta Oecologia, 12, 461-470.
Berendse F., Oomes M. J. M., Altena H. J. & De Visser W. (1994) A comparative study of nitrogen flows in two similar meadows affected by different groundwater levels. Journal of Applied Ecology, 31, 40-48.
Eschner D. & Liste H. H. (1995) Stoffdynamik wieder zu vernassender Niedermoore. Zeitschrift fur Kurlturtechnik und Landentwickung [Substance dynamics in the fens after rewetting], 36, 113-116.
Restore/create species-rich, semi-natural grassland
A 2007 review of experimental evidence on how to restore species-rich grassland on old arable fields (Diggelen 2007) found that removing excess nutrients is very slow if done simply by grazing and cutting hay (two studies), with only 3-5% of the soil nutrient pool removed each year. Removing topsoil can effectively remove nitrogen but not phosphorus (one study; Verhagen et al. 2001). The authors argued it is necessary to introduce plants by sowing because rare grassland species are under-represented in the seed bank. They found one review (Pywell et al. 2003) showing that plants that were good colonizers and competitors, associated with fertile soils were most likely to establish in restoration experiments. Two sets of experiments demonstrated that seedlings of grassland or wet grassland plants survive less well in low light conditions (as in a dense productive grassland).
Verhagen R., Klooker J., Bakker J.P. & van Diggelen R. (2001) Restoration success of low-production plant communities on former agricultural soils after topsoil removal. Applied Vegetation Science, 4, 75-82.
Pywell R. F., Bullock J. M., Roy D. B., Warman E. A., Walker K. J. & Rothery P. (2003) Plant traits as predictors of performance in ecological restoration. Journal of Applied Ecology, 40, 65-77.