Study

Reintroduction of salt marsh vegetation and phosphorus fertilisation improve plant colonisation on seawater-contaminated cutover bogs

  • Published source details Emond C., Lapointe L., Hugron S. & Rochefort L. (2016) Reintroduction of salt marsh vegetation and phosphorus fertilisation improve plant colonisation on seawater-contaminated cutover bogs. Mires and Peat, 18, Article-17

Actions

This study is summarised as evidence for the following.

Action Category

Add inorganic fertilizer: brackish/salt marshes

Action Link
Marsh and Swamp Conservation

Introduce fragments of non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation

Add lime or similar chemicals before/after planting non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation

Introduce fragments of non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation

Add lime or similar chemicals 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
  1. Add inorganic fertilizer: brackish/salt marshes

    A replicated, paired, controlled, before-and-after study in 2011–2012 in two salt-contaminated bogs in New Brunswick, Canada (Emond et al. 2016) found that fertilizing without introducing salt marsh vegetation had no significant effect on cover of salt marsh plants. After one year, cover of salt marsh plant species was very low in both fertilized bog plots (0% cover) and unfertilized bog plots (<0.1% cover). Methods: In summer 2011, sixteen 9-m2 plots were established (in four sets of four) on bare, salt-contaminated peat. Eight plots (two plots/block) were fertilized with rock phosphate, spread across the plot surface (50 g/m2) or placed in 49 holes/plot (9 g/hole). The other eight plots were not fertilized. Half of the fertilized and unfertilized plots were also limed, but no vegetation was introduced to any of the plots. In July 2012, cover of salt marsh plants (i.e. species present in a nearby salt marsh) was recorded in one 4-m2 quadrat/plot.

    (Summarised by: Nigel Taylor)

  2. Introduce fragments of non-woody plants: brackish/saline wetlands

    A replicated, paired, controlled, before-and-after study in 2011–2012 in two salt-contaminated bogs in New Brunswick, Canada (Emond et al. 2016) found that plots planted with rhizomes of salt marsh herbs contained a similar overall vegetation biomass to unplanted plots. Plots were initially bare peat. After one year, total above-ground vegetation biomass did not significantly differ between plots planted with chaffy sedge Carex paleacea (150 g/m2), plots planted with prairie cordgrass Spartina pectinata (66 g/m2) and unplanted plots (122 g/m2). In the plots where it was planted, chaffy sedge biomass was 120 g/m2 and it had 9–17% cover. In the plots where it was planted, prairie cordgrass biomass was 24 g/m2, and it had 2–3% cover. Methods: In June 2011, forty-eight 9-m2 plots were established across the two bogs, in four blocks of twelve. Plugs of rhizomes and soil (5 cm diameter) from an adjacent salt marsh were added to 32 of the plots (eight plots/block; four with sedge rhizomes and four with cordgrass rhizomes). Phosphorous fertilizer and lime were each applied to one plot per treatment. In July 2012, vegetation cover was recorded in the central 4 m2 of each plot. Vegetation was cut from one 250-cm2 quadrat/plot, then dried and weighed. This study shared part of the experimental set-up used in (2).

    (Summarised by: Nigel Taylor)

  3. Add lime or similar chemicals before/after planting non-woody plants: brackish/saline wetlands

    A replicated, paired, controlled, before-and-after study in 2011–2012 in two salt-contaminated bogs in New Brunswick, Canada (Emond et al. 2016) found that liming reduced the biomass of planted salt marsh vegetation. After one year, limed plots supported a lower above-ground biomass of planted vegetation (26 g/m2) than unlimed plots (42 g/m2). This result is not based on an assessment of statistical significance. Methods: In summer 2011, eighty 9-m2 plots were established (in four blocks of 20) on bare, salt-contaminated peat (0.5–1.4 ppt). Sixty-four of the plots were planted with vegetation (chaffy sedge, prairie cordgrass, or mixed salt marsh plant fragments). Half of the plots were limed (18 g in planting holes; increasing soil pH to 3.8). The other half were not (soil pH 3.5). Some limed and unlimed plots were also fertilized. In July 2012, vegetation was cut from a 250-cm2 quadrat in each plot, then dried and weighed.

    (Summarised by: Nigel Taylor)

  4. Introduce fragments of non-woody plants: brackish/saline wetlands

    A replicated, paired, controlled, before-and-after study in 2011–2012 in two salt-contaminated bogs in New Brunswick, Canada (Emond et al. 2016) found that plots sown with salt marsh vegetation fragments developed greater cover of introduced herb species than unsown plots, but similar biomass of these species and vegetation overall. Before sowing, plots were bare peat. After one year, sown plots had greater cover of introduced herb species (i.e. the 15 species present at the donor site; 1–4%) than unsown plots (<1%). However, there was no significant difference between treatments in biomass of introduced species (sown: 12–14 g/m2; not sown: 0 g/m2) or vegetation overall (sown: 126–155 g/m2; not sown: 122 g/m2). Methods: In June 2011, forty-eight 9-m2 plots were established across the two bogs, in four blocks of twelve. Vegetation fragments from an adjacent salt marsh were added to 32 of the plots (eight plots/block; four in July, four in August). Phosphorous fertilizer and lime were each applied to half of the plots. In July 2012, vegetation cover was recorded in the central 4 m2 of each plot. Vegetation was cut from one 250-cm2 quadrat/plot, then dried and weighed. This study shared part of the experimental set-up used in (1).

    (Summarised by: Nigel Taylor)

  5. Add lime or similar chemicals before/after planting non-woody plants: brackish/saline wetlands

    A replicated, randomized, paired, controlled study in 2011–2012 in a greenhouse in New Brunswick, Canada (Emond et al. 2016) found that liming had no significant effect on seed germination rate of two salt marsh herbs, but reduced the height of transplants of one species and reduced the above-ground biomass of both. For both species, a statistically similar number of seeds germinated over two months in limed and unlimed pots (data not reported). After four months, chaffy sedge Carex paleacea transplants were shorter in limed than unlimed pots, whilst prairie cordgrass Spartina pectinata height did not significantly differ between limed and unlimed plots (data not reported). However, above-ground biomass of transplants was significantly lower for limed than unlimed chaffy sedge (high lime: 30; low lime: 50; no lime: 87 g/m2) and significantly lower for heavily limed than unlimed prairie cordgrass (high lime: 31; low lime: 54; no lime: 69 g/m2). Methods: In October 2011, five pots of salt-contaminated peat were planted per treatment: sedge or cordgrass, with no lime (pH 3.8), low lime (2.5 kg/m3; pH 4.7) or high lime (7.5 kg/m3; pH 6.2). Pots were kept in five groups, each containing one pot of each treatment. Seeds and transplants were kept in the dark at 4°C for three months before planting. Seeds were also kept in brackish water for two weeks before sowing. Seed germination was recorded after two months. After four months, all transplants were measured, cut, dried and weighed.

    (Summarised by: Nigel Taylor)

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

    A replicated, paired, controlled, before-and-after study in 2011–2012 in two salt-contaminated bogs in New Brunswick, Canada (Emond et al. 2016) found that adding fertilizer before introducing vegetation increased overall vegetation cover and above-ground biomass, but had no significant effect on the height of transplanted herbs. After one year, fertilized plots contained more vegetation overall than unfertilized plots. This was true in terms of cover (fertilized: 25%; unfertilized: 13%) and above-ground biomass (fertilized: 161 g/m2; unfertilized: 86 g/m2). Meanwhile, the height of transplanted vegetation did not significantly differ between fertilized and unfertilized plots. This was true for chaffy sedge Carex paleacea (fertilized: 36 cm; unfertilized: 31 cm) and prairie cordgrass Spartina pectinata (fertilized: 25 cm; unfertilized: 19 cm). Methods: In summer 2011, eighty 9-m2 plots were established (in four blocks of 20) on bare, salt-contaminated peat (0.5–1.4 ppt). Sixty-four of the plots were planted with vegetation (chaffy sedge, prairie cordgrass, or mixed salt marsh plant fragments). Half of the plots were fertilized (9 g rock phosphate fertilizer in planting holes) and half were left unfertilized. Some fertilized and unfertilized plots were also limed. In July 2012, vegetation cover was recorded in one 4-m2 quadrat in each plot. Vegetation was cut from a 250-cm2 quadrat then dried and weighed.

    (Summarised by: Nigel Taylor)

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