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Individual study: Restoration of cut-over raised bogs in southern Germany – a comparison of methods

Published source details

Sliva J. & Pfadenhauer J. (1999) Restoration of cut-over raised bogs in southern Germany – a comparison of methods. Applied Vegetation Science, 2, 137-148


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Cover peatland with something other than mulch (without planting) Peatland Conservation

A replicated, controlled, before-and-after study in 1993–1995 in a historically mined raised bog in Germany (Sliva et al. 1999) reported that covering plots with fleece or fibre mat did not affect seedling numbers for five plant species. These results were not tested for statistical significance. After 1–2 years, covered and uncovered plots contained a similar number of seedlings. There were 3 seedlings/400 cm2 for purple moor grass Molinia caerulea. There was <1 seedling/400 cm2 for four other species: beaked sedge Carex rostrata, common cottongrass Eriophorum angustifolium, sheathed cottongrass Eriophorum vaginatum and heather Calluna vulgaris. In autumn 1993, fifteen 1 m2 plots were established on bare rewetted peat (mined until 1986). Five plots were covered with synthetic fleece, five were covered with wide-meshed jute fibre mat and five were not covered. No seeds were added to these plots. Covers were removed and seedlings counted in summer 1994 (two plots/treatment) and 1995 (three plots/treatment).

(Summarised by Nigel Taylor)

Introduce seeds of peatland trees/shrubs Peatland Conservation

A replicated, controlled, before-and-after study in 1993–1995 in a historically mined raised bog in Germany (Sliva & Pfadenhauer 1999) reported that planted heather Calluna vulgaris seeds germinated, and that some seedlings survived over two years – although survival depended on whether plots were covered. In covered plots, there were 6–24 seedlings/400 cm2 after one year and 25–35 seedlings/400 cm2 after two years. There were significantly fewer seedlings in uncovered plots: 5 seedlings/400 cm2 after one year and 0–1 seedlings/400 cm2 after two years. Unseeded plots contained no heather seedlings, whether covered or not. In autumn 1993, twenty 1 m2 plots of bare rewetted peat were sown with heather seeds (40–48 seeds/400 cm2). Five plots were then covered with mulch, five with synthetic fleece and five with jute fibre mat for one or two winters, whilst five were not covered. Fifteen additional plots were not sown (but some were covered). Seedlings were counted in summer 1994 (two plots/treatment) and 1995 (three plots/treatment).

(Summarised by Nigel Taylor)

Introduce seeds of peatland herbs Peatland Conservation

A replicated, controlled, before-and-after study in 1993–1995 in a historically mined raised bog in Germany (Sliva & Pfadenhauer 1999) reported that planted seeds germinated for three of four herb species, and that seedlings survived over two years. After two years, seedling densities (seedlings/400 cm2) were 8–45 for purple moor grass Molinia caerulea, 4–10 for sheathed cottongrass Eriophorum vaginatum, 0–1 for common cottongrass Eriophorum angustifolium and 0 for beaked sedge Carex rostrata (i.e. it did not germinate). In unsown plots, there were 0–3 seedlings/400 cm2. Plots covered with mulch, fleece or fibre mats after sowing contained more moor grass and sheathed cottongrass seedlings (14–45 seedlings/400 cm2) than uncovered plots (0–8 seedlings/400 cm2). In autumn 1993, seeds of the four species were spread onto 1 m2 plots of bare rewetted peat (20 plots/species; 40–48 seeds/400 cm2). Five plots/species were covered with mulch, five with synthetic fleece and five with jute fibre mat, whilst five were not covered. Fifteen additional plots were not seeded (but some were covered). Seedlings were counted in summer 1994 (two plots/treatment) and 1995 (three plots/treatment).

(Summarised by Nigel Taylor)

Directly plant peatland herbs Peatland Conservation

A replicated before-and-after study in 1991–1995 in a historically mined raised bog in Germany (Sliva & Pfadenhauer 1999) reported that planted herbs grew. Three species were planted. After four years, sedge Carex rostrata plants had 40 shoots (vs 1 shoot when planted), common cottongrass Eriophorum angustifolium plants had 2 shoots (vs 1 shoot when planted) and tussocks of sheathed cottonsedge Eriophorum vaginatum were 70 cm in diameter (vs 40 cm after two years). These results were not tested for statistical significance. For the first two species, additional fertilized plants developed more shoots than unfertilized plants (sedges: 142 shoots/plant; common cottongrass: 6 shoots/plant) but fertilizer had no significant effect on sheathed cottonsedge tussock diameter. In 1991, twelve 3 x 35 m plots of bare rewetted peat were planted with the shoots and tussocks (one plant/3 m2). In 1994, six plots were fertilized (nitrogen-phosphorous-potassium; 100 g/m2). Plants were measured in 1991, 1993 and 1995.

(Summarised by Nigel Taylor)

Add inorganic fertilizer (without planting) Peatland Conservation

A replicated, controlled, before-and-after study in 1995 in a historically mined raised bog in Germany (Sliva et al. 1999) found that fertilizer increased seedling growth in 15 of 48 comparisons, all involving phosphorous, but had no effect in the other 33 comparisons. After four months, seedlings in plots fertilized with phosphorous (either alone or in combination with nitrogen and potassium) were significantly taller than seedlings in unfertilized plots in 15 of 24 comparisons (for which fertilized: 2–18 cm; unfertilized: 1–4 cm). Seedlings in plots fertilized only with nitrogen or potassium were never significantly taller than unfertilized seedlings (0 of 24 comparisons; fertilized: 1–5 cm; unfertilized: 2–4 cm). In spring 1995, six 16 m2 plots of recently rewetted bare peat received each fertilizer treatment: N, P, K, or a mix of all three. Eight additional plots were not fertilized. After four months, all seedlings of six plant species (four herbs and two shrubs) were measured in every plot.

(Summarised by Nigel Taylor)

Cover peatland with organic mulch (after planting) Peatland Conservation

A replicated, controlled, before-and-after study in 1993–1995 in a historically mined raised bog in Germany (Sliva & Pfadenhauer 1999) found that mulching plots sown with herb or shrub seeds increased germination for two of five species. For purple moor grass Molinia caerulea and heather Calluna vulgaris, mulched plots contained more seedlings after 1–2 years than unmulched plots (25–45 vs 1–8 seedlings/400 cm2). For three other herb species, mulched and unmulched plots contained a similar number of seedlings (0–10 vs 0–8 seedlings/400 cm2). In autumn 1993, seeds of five plant species were spread onto 1 m2 plots of bare rewetted peat (10 plots/species, 40–48 seeds/400 cm2). Five plots/species were mulched with leaves or heather branches, whilst five were not mulched. Mulch was removed and seedlings counted in summer 1994 (two plots/treatment) and 1995 (three plots/treatment).

(Summarised by Nigel Taylor)

Add inorganic fertilizer (before/after planting) Peatland Conservation

A replicated, controlled, before-and-after study in 1991–1995 in a historically mined raised bog in Germany (Sliva & Pfadenhauer 1999) found that fertilization increased growth of two of three planted herb species. One year after fertilization, there were more shoots on fertilized than unfertilized sedge Carex rostrata (142 vs 45 shoots/plant) and common cottongrass Eriophorum angustifolium (6 vs 2 shoots/plant). However, sheathed cottongrass Eriophorum vaginatum tussocks had similar diameters whether fertilized (69 cm) or not (70 cm). In 1991, twelve 3 x 35 m plots of bare rewetted peat were planted with the shoots and tussocks (one plant/3 m2). At this point, plants destined to be fertilized and unfertilized did not differ in shoot number or tussock diameter. In 1994, six of the plots were fertilized (mixture of N, P and K compounds; 100 g/m2). In 1995, shoot number and tussock diameter were re-measured on each plant.

(Summarised by Nigel Taylor)

Directly plant peatland mosses Peatland Conservation

A replicated before-and-after study in 1991–1995 in a historically mined raised bog in Germany (Sliva et al. 1999) reported that transplanted sods of Sphagnum moss grew larger in one of five sites but did not grow (or shrunk) in the other four. No statistical tests were carried out. Sods of three Sphagnum species increased in diameter when planted at a site with sedge Carex sp. present (from 20 cm to 54–82 cm over four years). The species were Magellanic bog moss Sphagnum magellanicum, feathery bog moss Sphagnum cuspidatum and red bog moss Sphagnum capillifolium. All three species did not grow, or shrunk, when planted between Eriophorum cottongrass at three sites or into an unvegetated site (from 20 cm to 0–23 cm). Cover of living Sphagnum within the sods showed similar responses. In 1991, five sites in a historically mined but rewetted bog were planted with 20 sods (25 cm thick, 12 cm diameter) of each Sphagnum species. From 1992 to 1995, sod diameter and cover of living Sphagnum were recorded.

(Summarised by Nigel Taylor)

Cover peatland with something other than mulch (after planting) Peatland Conservation

A replicated, controlled, before-and-after study in 1993–1995 in a historically mined raised bog in Germany (Sliva & Pfadenhauer 1999) reported that covering plots with fleece or fibre mats did not affect germination of three of five sown species but increased germination of the other two. These results are not based on tests of statistical significance. For three herb species, there were a similar number of seedlings after 1–2 years in covered plots (0–11 seedlings/400 cm2) and uncovered plots (0–10 seedlings/400 cm2). In contrast, for one herb and one shrub species, there were 14–27 seedlings/400 cm2 in covered plots but only 1–8 seedlings/400 cm2 in uncovered plots. Fleece and fibre mat had similar effects on seedling number (see original paper). Covers had no effect on germination in additional plots that were not sown (see intervention Cover peatland without planting). In autumn 1993, seeds of five plant species were spread onto 1 m2 plots of bare rewetted peat (15 plots/species; 40–48 seeds/400 cm2). Five plots/species were covered with synthetic fleece, five with wide-meshed jute fibre mat, and five were not covered. Covers were removed and seedlings counted in summer 1994 (two plots/treatment) and 1995 (three plots/treatment).

(Summarised by Nigel Taylor)