Study

Revegetation trials in salt-marsh degraded by lesser snow goose Anser caerulescens caerulescens grazing at La Pérouse Bay, Manitoba, Canada

  • Published source details Handa I.T. & Jeffries R.L. (2000) Assisted revegetation trials in degraded salt-marshes. Journal of Applied Ecology, 37, 944-958

Actions

This study is summarised as evidence for the following.

Action Category

Add surface mulch before/after planting non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation

Add inorganic fertilizer before/after planting non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation

Directly plant non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation
  1. Add surface mulch before/after planting non-woody plants: brackish/saline wetlands

    A replicated, randomized, paired, controlled study in 1996–1997 in two degraded, intertidal, brackish marshes in Manitoba, Canada (Handa & Jeffries 2000) found that adding surface mulch increased the cover of one of two planted herb species, but did not significantly affect survival rates of either species or overall above-ground biomass. On all five survey dates across the second growing season after planting, creeping alkaligrass Puccinellia phryganodes cover was higher in mulched plots (1,820–5,400 mm2/m2) than unmulched plots (1,090–3,810 mm2/m2). However, cover of estuary sedge Carex subspathacea never significantly differed between treatments (mulched: 670–2,880 mm2/m2; unmulched: 720–2,600 mm2/m2). On all five dates, survival rates were statistically similar under each treatment for both alkaligrass (mulched: 87–100%; unmulched: 52–93%) and estuary sedge (mulched: 28–58%; unmulched: 23–50%). On at least two of three dates (results not clearly reported), live above-ground biomass was statistically similar under each treatment for both alkaligrass-dominated vegetation (mulched: 45–178 g/m2; unmulched: 29–122 g/m2) and sedge-dominated vegetation (mulched: 1–4 g/m2; unmulched: 1–4 g/m2). Methods: In June 1996, plugs of creeping alkaligrass and estuary sedge were transplanted from natural stands to 1-m2 plots within brackish marsh vegetation damaged by geese (one species/marsh; 12 plots/species; 42 plugs/plot). Two random quarters of each plot were mulched after planting (5 mm layer of peat from a nearby marsh). Half of each plot was also fertilized. All plots were fenced to exclude geese. Vegetation was surveyed in summer 1997. Survival and cover were monitored for planted plants in the centre of each plot. Vegetation samples were cut from the margins of each plot, then washed to remove dead biomass, dried and weighed.

    (Summarised by: Nigel Taylor)

  2. Add inorganic fertilizer before/after planting non-woody plants: brackish/saline wetlands

    A replicated, randomized, paired, controlled study in 1996–1997 in two degraded, intertidal, brackish marshes in Manitoba, Canada (Handa & Jeffries 2000) found that adding fertilizer increased the cover of one of two planted herb species, but did not significantly affect survival rates of either species or overall above-ground biomass. On all five survey dates across the second growing season after planting, creeping alkaligrass Puccinellia phryganodes cover was higher in fertilized plots (1,720–5,400 mm2/m2) than in unfertilized plots (1,020–4,870 mm2/m2). However, cover of estuary sedge Carex subspathacea never significantly differed between treatments (fertilized: 670–2,880 mm2/m2; unfertilized: 670–2,720 mm2/m2). On all five dates, survival rates were statistically similar under each treatment, for both alkaligrass (fertilized: 52–100%; unfertilized: 47–100%) and estuary sedge (fertilized: 24–58%; unfertilized: 23–50%). On at least two of three dates (results not clearly reported), live above-ground biomass was statistically similar under each treatment for both alkaligrass-dominated vegetation (fertilized: 47–178 g/m2; unfertilized: 29–99 g/m2) and sedge-dominated vegetation (fertilized: 1–4 g/m2; unfertilized: 1–4 g/m2). Methods: In June 1996, plugs of creeping alkaligrass and estuary sedge were transplanted from natural stands to 1-m2 plots within brackish marsh vegetation damaged by geese (one species/marsh; 12 plots/species; 42 plugs/plot). Two random quarters of each plot were fertilized with N and P at planting (10.5 g N/m2 and 4.5 g P/m2). Half of each plot was also mulched. All plots were fenced to exclude geese. Vegetation was surveyed in summer 1997. Survival and cover were monitored for planted plants in the centre of each plot. Vegetation samples were cut from the margins of each plot, then washed to remove dead biomass, dried and weighed.

    (Summarised by: Nigel Taylor)

  3. Directly plant non-woody plants: brackish/saline wetlands

    A replicated study in 1996–1997 in two degraded, coastal, brackish marshes in Manitoba, Canada (Handa & Jeffries 2000) reported 24–100% survival of two transplanted herb species after two growing seasons, and that their cover had increased. Statistical significance was not assessed. Two growing seasons after planting, creeping alkaligrass Puccinellia phryganodes had a survival rate of 47–100% and black estuary sedge Carex subspathacea had a survival rate of 24–50%. Cover of surviving alkaligrass was 1,600–5,400 mm2/m2 (vs 200 mm2/m2 when planted). Cover of surviving estuary sedge was 700–2,800 mm2/m2 (vs 200 mm2/m2 when planted). Adding mulch or fertilizer significantly increased the cover of alkaligrass but not estuary sedge, and did not significantly affect survival rates (see Actions: Add surface mulch before/after planting and Add inorganic fertilizer before/after planting). Methods: In June 1996, plugs of alkaligrass and estuary sedge were transplanted from natural stands to 1-m2 plots within brackish marsh vegetation damaged by geese (one species/marsh; 12 plots/species; 42 plugs/plot). All plots were fenced to exclude geese. Mulch (5 mm peat layer) and/or fertilizer (N and P) were added to three quarters of each planted plot. Survival and cover (basal area) of planted vegetation in the centre of each plot were monitored until mid-August 1997.

    (Summarised by: Nigel Taylor)

Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust