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Providing evidence to improve practice

Individual study: The regeneration capabilities of bryophytes for rich fen restoration

Published source details

Mälson K. & Rydin H. (2007) The regeneration capabilities of bryophytes for rich fen restoration. Biological Conservation, 135, 435-442


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

Add lime (before/after planting) Peatland Conservation

A replicated, randomized, paired, controlled, before-and-after study in 2004–2005 in a degraded fen in Sweden (Mälson & Rydin 2007) found that liming increased survival and spread of sown fen mosses. After one growing season, moss survival was significantly higher in plots that had been limed (60–93% of plots contained live moss shoots) than in unlimed plots (4–48%). After two growing seasons, moss cover was significantly higher in limed plots (8–34%) than in unlimed plots (<1–10%). In June 2004, ninety-six 9 cm2 plots were established, in four equal blocks, on rewetted (historically drained) bare peat. Fragments of four fen-characteristic moss species were added (16 fragments of a single species in 9 cm2 subplots) to 24 plots (625 cm2). Twelve of these had been limed before planting (1.2 kg/m2, raising pH from 4.9 to 6.3). Some plots were also covered (with sedge litter or plastic gauze) after planting. Moss survival was assessed after one growing season. Moss cover was visually estimated after two growing seasons.

(Summarised by Nigel Taylor)

Add lime (before/after planting) Peatland Conservation

A replicated, controlled, before-and-after study in a greenhouse in Sweden (Mälson & Rydin 2007) found that liming increased the growth rate of planted fen mosses. After five months, shoots of all four planted moss species were longer in limed trays (42–91 mm) than in unlimed trays (29–61 mm). When planted, fragments were 10 mm long. Four trays of peat (19 x 56 cm) were each planted with 160 moss fragments: ten clusters of four fragments, for each of four species. In two of the trays, lime had been mixed into the peat before planting (128 g/tray). All trays were covered with clear plastic lids, kept in controlled light conditions, watered and systematically rearranged every 10 days. After five months, the length of all planted fragments was measured.

(Summarised by Nigel Taylor)

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

A replicated, randomized, paired, controlled, before-and-after study in 2004–2005 in a degraded fen in Sweden (Mälson & Rydin 2007) reported that shading plots with plastic mesh increased survival and spread of planted moss fragments. These results are not based on tests of statistical significance. After one growing season, moss survival was 48–93% in shaded plots but only 4–60% in unshaded plots. After two growing seasons the pattern was similar: moss survival was 5–34% in shaded plots but <1–28% in unshaded plots. In June 2004, fragments of four fen-characteristic moss species were added (16 fragments of a single species in 9 cm2 subplots) to 16 plots (625 cm2) of bare rewetted peat. Eight plots were then shaded with plastic horticultural mesh (blocking 15% of incoming light). The other eight plots were not shaded. Some plots were also limed before planting. Moss survival was assessed after one growing season. Moss cover was visually estimated after two growing seasons.

(Summarised by Nigel Taylor)

Add mosses to peatland surface Peatland Conservation

A replicated before-and-after study in 2004–2005 in a degraded fen in Sweden (Mälson & Rydin 2007) reported that four sown fen-characteristic moss species had variable survival after one growing season, and developed variable cover after two growing seasons. Before sowing, plots were bare peat. One growing season after sowing, 4–93% of moss fragments had survived. Two growing seasons after planting, cover of fen-characteristic mosses was <1–34%. Additionally, survival and cover were significantly higher in limed than unlimed plots (see intervention Add lime before/after planting) and in plots covered with mulch or plastic gauze than uncovered plots (see intervention Cover peatland after planting). In June 2004, fragments of four fen-characteristic moss species were added to 24 plots (625 cm2) of bare rewetted peat: two scorpion mosses Scorpidium spp., three-ranked spear moss Pseudocalliergon trifarium, and starry feather moss Campylium stellatum. Each species was sown in separate 9 cm2 subplots (number not reported; density 16 fragments/subplot). Twelve plots were also limed and eight were covered (with sedge litter or plastic gauze). After one growing season, moss survival was assessed in each subplot. After two growing seasons, moss cover was visually estimated.

(Summarised by Nigel Taylor)

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

A replicated, randomized, controlled, before-and-after study in a degraded fen in Sweden (Mälson & Rydin 2007) found that shading trays with plastic mesh reduced growth of one of two planted moss species, but did not affect growth of the other. After four months, shoots of intermediate hook moss Scorpidium cossonii were lighter in shaded trays (5–10 mg dry mass) than in unshaded trays (7–14 mg). In contrast, the mass of starry feather moss Campylium stellatum shoots was similar in shaded (4–5 mg) and unshaded trays (3–6 mg). When planted, shoots weighed approximately 1 mg. Six 33 x 33 cm trays of limed peat were set up, floating in a drainage ditch. Three of the trays were shaded with plastic mesh (blocking 45% of incoming light). Each tray was planted with 32 random fragments of each moss species, in single-species clusters. A subsample of fragments was dried and weighed before planting. After four months, all planted fragments were collected, rinsed, dried and weighed.

(Summarised by Nigel Taylor)

Cover peatland with organic mulch (after planting) Peatland Conservation

A replicated, randomized, paired, controlled, before-and-after study in 2004–2005 in a degraded fen in Sweden (Mälson & Rydin 2007) reported that mulching with sedge litter increased survival and growth of planted moss fragments, but only when plots were not limed. These results are not based on tests of statistical significance. Amongst unlimed plots, moss survival after one growing season was higher in mulched plots (13% of plots contained live moss) than in unmulched plots (4%). Moss cover after two growing seasons was higher in mulched plots (3–7%) than unmulched plots (≤1%). However, amongst limed plots, mulching had no effect on survival (mulched: 62%; unmulched: 60%) or growth (mulched: 13–24%; unmulched: 8–28%). In June 2004, fragments of four fen-characteristic moss species were added (16 fragments of a single species in 9 cm2 subplots) to 16 plots (625 cm2) of bare rewetted peat. Eight plots were then sparsely mulched with sedge Carex lasiocarpa litter. The other eight plots were not mulched. Eight plots were also limed before planting. Moss survival was assessed after one growing season and moss cover visually estimated after two.

(Summarised by Nigel Taylor)