Changes in wet meadow vegetation after 20 years of different management in a field experiment (north-west Germany)

Published source details Poptcheva K., Schwartze P., Vogel A., Kleinebecker T. & Hölzel N. (2009) Changes in wet meadow vegetation after 20 years of different management in a field experiment (north-west Germany). Agriculture, Ecosystems & Environment, 134, 108-114.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Add inorganic fertilizer: freshwater marshes Action Link
	Cut/mow herbaceous plants to maintain or restore disturbance: freshwater marshes Action Link
	Restore or create traditional water meadows Action Link

Add inorganic fertilizer: freshwater marshes

A replicated, paired, controlled, before-and-after study in 1987–2007 in two wet grasslands in northwest Germany (Poptcheva et al. 2009) reported that fertilized plots contained more plant biomass than unfertilized plots after 4–18 years, but that fertilizer had no consistent effect on vegetation cover, height or species richness. In the first year of the study, above-ground vegetation biomass was statistically similar in fertilized plots (540–590 g/m²) and unfertilized plots (480–510 g/m²). However, after 4–18 years of intervention, above-ground vegetation biomass was significantly greater in fertilized plots (520–820 g/m²) than unfertilized plots (240–390 g/m²). Over 20 years, other vegetation metrics did not respond clearly or consistently to fertilization across the two wet grasslands (data reported as graphical analyses; statistical significance of differences not assessed). These metrics included cover of plant groups (e.g. sedges, rushes, forbs), vegetation height, species richness and community moisture preference. Methods: In 1987, two plots (each 200–250 m²) were established in each of two wet grassland sites (with non-peaty soils, and maintained as fertilized pasture prior to the study). From 1987, all four plots were mown twice each year (June/July and September). From 1989, one plot in each meadow was also fertilized each year in early spring (60 kg/ha P₂O₅ and 120 kg/ha K₂O). Vegetation was surveyed in mid-June. Cover/abundance of all plant species was recorded in four 4-m² quadrats/plot, every one or two years between 1987 and 2007. Vegetation was cut from eight 0.25-m² quadrats/plot in 1989, 1993, 1998 and 2007, then dried and weighed.

(Summarised by: Nigel Taylor)
Cut/mow herbaceous plants to maintain or restore disturbance: freshwater marshes

A replicated, paired, controlled, before-and-after study in 1987–2007 in three wet grasslands in northwest Germany (Poptcheva et al. 2009) reported that plots mown twice each year experienced similar vegetation changes to unmown plots, with the exception of sedge abundance, species richness and community moisture value. Statistical significance was not assessed. Over 20 years, mown plots experienced increases in sedge cover, plant species richness, and the average moisture preference of the vegetation. In contrast, these metrics decreased in unmown plots. Other changes over time were similar (in direction if not in magnitude) in both mown and unmown plots. There were increases in rush cover, tall forb cover, fern cover and vegetation height. There were decreases in cover of grasses, legumes and short forbs. All data were reported as graphical analyses. Methods: From 1987, one plot (200–250 m²) in each of three wet grassland sites was mown (in June/July and September each year). One additional plot in each site was not mown. These sites had non-peaty soils, and had been maintained as fertilized pasture (one also mown) prior to the study. Trees and shrubs were removed from all plots throughout the study. Vegetation was surveyed in mid-June, every one or two years, between 1987 and 2007.

(Summarised by: Nigel Taylor)
Restore or create traditional water meadows

A long-term replicated trial in 1987-2007 on seven semi-natural wet meadow sites in Münsterland, Germany (Poptcheva et al. 2009) found that mowing twice a year (in June/July and September) without fertilizer was the most effective regime for restoring target wet meadow plant communities and resulted in highest species richness. However, successional changes were still happening 20 years after the start of the trial, probably due to slow immigration of new species. Management regime had a stronger effect on the pattern of succession than other environmental or historic factors. Treatments were carried out from 1987 to 2007 in 200-250 m² fields and plants were surveyed in four 2 x 2 m plots/field at least every second year. Above ground biomass was measured in 1989, 1993, 1998 and 2007 by harvesting eight 0.5 x 0.5 m plots/field.