Version classiqueVersion mobile

What Works in Conservation 2018

 | 
William J. Sutherland
, 
Lynn V. Dicks
, 
Nancy Ockendon
, 
et al.

6. Peatland conservation

6.12. Actions to complement planting

Texte intégral

Likely to be beneficial

● Cover peatland with organic mulch (after planting)

1 Germination: One replicated, controlled, before-and-after study in a bog in Germany found that mulching after sowing seeds increased germination of two species (a grass and a shrub), but had no effect on three other herb species.

2 Survival: Two replicated, paired, controlled studies in a fen in Sweden and a bog in the USA reported that mulching increased survival of planted vegetation (mosses or sedges). One replicated, paired, controlled study in Indonesia reported that mulching with oil palm fruits reduced survival of planted peat swamp tree seedlings.

3 Growth: One replicated, randomized, paired, controlled, before-and-after study in a fen in the USA reported that mulching increased growth of transplanted water sedge Carex aquatilis.

4 Cover: Six studies (including four replicated, randomized, paired, controlled, before-and-after) in bogs in Canada and the USA, and a fen in Sweden, found that mulching after planting increased vegetation cover (specifically total vegetation, total mosses/bryophytes, Sphagnum mosses or vascular plants after 1–3 growing seasons). Three replicated, randomized, paired, controlled, before-and-after studies in bogs in Canada found that mulching after planting had no effect on vegetation cover (Sphagnum mosses or fen-characteristic plants).

5 Assessment: likely to be beneficial (effectiveness 60%; certainty 60%; harms 10%). Based on evidence from: bogs (nine studies); fens (two studies); tropical peat swamps (one study).

6https://www.conservationevidence.com/​actions/​1828

● Cover peatland with something other than mulch (after planting)

7 Germination: One replicated, controlled, before-and-after study in a bog in Germany reported mixed effects of fleece and fibre mats on germination of sown herb and shrub seeds (positive or no effect, depending on species).

8 Survival: Two replicated, randomized, controlled studies examined the effect, on plant survival, of covering planted areas. One study in a fen in Sweden reported that shading increased survival of planted mosses. One study in a nursery in Indonesia reported that shading did not affect survival of most studied peat swamp tree species, but increased survival of some.

9 Growth: Three replicated, randomized, controlled, before-and-after studies examined the effect, on plant growth, of covering planted areas. One study in a greenhouse in Switzerland found that covers, either transparent plastic or shading mesh, increased growth of planted Sphagnum moss. One study in a fen in Sweden found that shading with plastic mesh reduced growth of planted fen mosses. One study in a nursery in Indonesia reported that seedlings shaded with plastic mesh grew taller and thinner than unshaded seedlings.

10 Cover: Two replicated and paired studies, in a fen in Sweden and a bog in Australia, reported that shading plots with plastic mesh increased planted moss cover. One study in a bog in Canada found that covering sown plots with plastic mesh, but not transparent sheets, increased Sphagnum moss abundance. Another study in a bog in Canada reported that shading sown plots with plastic mesh did not affect cover of vegetation overall, vascular plants or mosses.

11 Assessment: likely to be beneficial (effectiveness 50%; certainty 50%; harms 10%). Based on evidence from: bogs (five studies); fens (two studies); tropical peat swamps (one study).

12https://www.conservationevidence.com/​actions/​1829

● Reprofile/relandscape peatland (before planting)

13 Survival: One replicated, paired, controlled study in a bog in Canada found that over one growing season, survival of sown Sphagnum mosses was higher in reprofiled basins than on raised plots.

14 Cover: Two replicated, controlled, before-and-after studies in bogs in Canada found that reprofiled basins had higher Sphagnum cover than raised plots, 3–4 growing seasons after sowing Sphagnum dominated vegetation fragments. One controlled study in a bog in Estonia reported that reprofiled and raised plots had similar Sphagnum cover, 1–2 years after sowing. All three studies found that reprofiled and raised plots developed similar cover of other mosses/bryophytes and vascular plants.

15 Assessment: likely to be beneficial (effectiveness 60%; certainty 40%; harms 5%). Based on evidence from: bogs (four studies).

16https://www.conservationevidence.com/​actions/​1833

Trade-off between benefit and harms

● Add inorganic fertilizer (before/after planting)

17 Survival: Two replicated, randomized, paired, controlled studies in bogs in Canada examined the effect, on plant survival, of adding inorganic fertilizer to areas planted with peatland plants. One study reported that fertilizer increased survival of two planted tree species. The other study found that fertilizer had no effect on three planted tree species and reduced survival of one.

18 Growth: Five studies (three replicated, randomized, paired, controlled) in bogs in the UK, Germany and Canada found that fertilizer typically increased growth of planted mosses, herbs or trees. However, for some species or in some conditions, fertilizer had no effect on growth. One replicated, randomized, controlled, before-and-after study in a nursery in Indonesia found that fertilizer typically had no effect on growth of peat swamp tree seedlings.

19 Cover: Three replicated, randomized, paired, controlled studies in bogs examined the effect, on vegetation cover, of adding inorganic fertilizer to areas planted with peatland plants. One study in Canada found that fertilizer increased total vegetation, vascular plant and bryophyte cover. Another study in Canada found that fertilizer increased cover of true sedges Carex spp. but had no effect on other vegetation. One study in New Zealand reported that fertilizer typically increased cover of a sown shrub and rush, but this depended on the chemical used and preparation of the peat.

20 Assessment: trade-off between benefit and harms (effectiveness 45%; certainty 40%; harms 20%). Based on evidence from: bogs (eight studies); tropical peat swamps (one study).

21https://www.conservationevidence.com/​actions/​1826

Unknown effectiveness (limited evidence)

● Introduce nurse plants (to aid focal peatland plants)

22 Survival: One replicated, paired, controlled study in Malaysia reported that planting nurse trees did not affect survival of planted peat swamp tree seedlings (averaged across six species).

23 Cover: Two replicated, randomized, paired, controlled, before-and-after studies in bogs in the USA and Canada found that planting nurse herbs had no effect on cover, after 2 – 3 years, of other planted vegetation (mosses/bryophytes, vascular plants or total cover).

24 Assessment: unknown effectiveness – limited evidence (effectiveness 30%; certainty 38%; harms 1%). Based on evidence from: bogs (two studies); tropical peat swamps (one study).

25https://www.conservationevidence.com/​actions/​1830

● Irrigate peatland (before/after planting)

26 Cover: One replicated, paired, controlled, before-and-after study in a bog in Canada found that irrigation increased the number of Sphagnum moss shoots present 1–2 growing seasons after sowing Sphagnum fragments.

27 Assessment: unknown effectiveness – limited evidence (effectiveness 60%; certainty 20%; harms 5%). Based on evidence from: bogs (one study).

28https://www.conservationevidence.com/​actions/​1832

● Create mounds or hollows (before planting)

29 Growth: One controlled study, in a peat swamp in Thailand, reported that trees planted into mounds of peat grew thicker stems than trees planted at ground level.

30 Cover: Two replicated, randomized, paired, controlled, before-and-after studies in bogs in Canada found that roughening the peat surface (e.g. by harrowing or adding peat blocks) did not significantly affect cover of planted Sphagnum moss, after 1–3 growing seasons.

31 Assessment: unknown effectiveness – limited evidence (effectiveness 30%; certainty 38%; harms 5%). Based on evidence from: bogs (two studies); tropical peat swamps (one study).

32https://www.conservationevidence.com/​actions/​1834

● Add fresh peat to peatland (before planting)

33 Cover: One replicated, controlled, before-and-after study in New Zealand reported that plots amended with fine peat supported higher cover of two sown plant species than the original (tilled) bog surface.

34 Assessment: unknown effectiveness – limited evidence (effectiveness 45%; certainty 25%; harms 5%). Based on evidence from: bogs (one study).

35https://www.conservationevidence.com/​actions/​1837

● Remove vegetation that could compete with planted peatland vegetation

36 Survival: One controlled study in a bog the UK reported that some Sphagnum moss survived when sown, in gel beads, into a plot where purple moor grass Molinia caerulea had previously been cut. No moss survived in a plot where grass had not been cut.

37 Assessment: unknown effectiveness – limited evidence (effectiveness 60%; certainty 20%; harms 2%). Based on evidence from: bogs (one study).

38https://www.conservationevidence.com/​actions/​1840

● Add root-associated fungi to plants (before planting)

39 Survival: Two controlled studies (one also replicated, paired, before-and-after) in peat swamps in Indonesia found that adding root fungi did not affect survival of planted red balau Shorea balangeran or jelutong Dyera polyphylla in all or most cases. However, one fungal treatment increased red balau survival.

40 Growth: Two replicated, controlled, before-and-after studies of peat swamp trees in Indonesia found that adding root fungi to seedlings, before planting, typically had no effect on their growth. However, one controlled study in Indonesia found that adding root fungi increased growth of red balau seedlings.

41 Assessment: unknown effectiveness – limited evidence (effectiveness 30%; certainty 35%; harms 0%). Based on evidence from: tropical peat swamps (three studies).

42https://www.conservationevidence.com/​actions/​1841

Likely to be ineffective or harmful

● Add lime (before/after planting)

43 Survival: One replicated, controlled study in the Netherlands reported that liming reduced survival of planted fen herbs after two growing seasons. One replicated, randomized, paired, controlled study in Sweden found that liming increased survival of planted fen mosses over one season.

44 Growth: Two controlled, before-and-after studies found that liming did not increase growth of planted peatland vegetation: for two Sphagnum moss species in bog pools in the UK, and for most species of peat swamp tree in a nursery in Indonesia. One replicated, controlled, before-and-after study in Sweden found that liming increased growth of planted fen mosses.

45 Cover: Of two replicated, randomized, paired, controlled studies, one in a fen in Sweden found that liming increased cover of sown mosses. The other, in a bog in Canada, found that liming plots sown with mixed fen vegetation did not affect vegetation cover (total, vascular plants or bryophytes).

46 Assessment: likely to be ineffective or harmful (effectiveness 35%; certainty 40%; harms 20%). Based on evidence from: bogs (two studies); fens (two studies); fen meadows (one study); tropical peat swamps (one study).

47https://www.conservationevidence.com/​actions/​1825

No evidence found (no assessment)

48We have captured no evidence for the following interventions:

  • Add organic fertilizer (before/after planting)
  • Rewet peatland (before/after planting)
  • Remove upper layer of peat/soil (before planting)
  • Bury upper layer of peat/soil (before planting)
  • Encapsulate planted moss fragments in beads/gel
  • Use fences or barriers to protect planted vegetation
  • Protect or prepare vegetation before planting (other interventions).

Table des illustrations

URL http://books.openedition.org/obp/docannexe/image/6584/img-1.jpg
Fichier image/jpeg, 459k

Lire

Open access

Acheter

Rechercher dans OpenEdition Search

Vous allez être redirigé vers OpenEdition Search