Study

Restoring forest in wetlands dominated by reed canarygrass: the effects of pre-planting treatments on early survival of planted stock

  • Published source details Hovick S.M. & Reinartz J.A. (2007) Restoring forest in wetlands dominated by reed canarygrass: the effects of pre-planting treatments on early survival of planted stock. Wetlands, 27, 24-39.

Actions

This study is summarised as evidence for the following.

Action Category

Use cutting/mowing to control problematic herbaceous plants: freshwater swamps

Action Link
Marsh and Swamp Conservation

Use herbicide to control problematic plants: freshwater swamps

Action Link
Marsh and Swamp Conservation

Physically damage problematic plants: freshwater swamps

Action Link
Marsh and Swamp Conservation

Use prescribed fire to control problematic plants: freshwater swamps

Action Link
Marsh and Swamp Conservation

Remove vegetation that could compete with planted trees/shrubs: freshwater wetlands

Action Link
Marsh and Swamp Conservation

Directly plant trees/shrubs: freshwater wetlands

Action Link
Marsh and Swamp Conservation
  1. Use cutting/mowing to control problematic herbaceous plants: freshwater swamps

    A replicated, controlled study in 2002–2004 aiming to restore a swamp in a reed canarygrass Phalaris arundinacea stand in Wisconsin, USA (Hovick & Reinartz 2007) reported that mowing before spraying herbicide affected the abundance of some individual plant species compared to spraying alone, but found no additional effect on plant diversity, plant richness, or the number of tree seedlings. After two growing seasons, overall plant diversity did not significantly differ between mown/sprayed plots and plots that had only been sprayed (data reported as a diversity index). The same was true for overall plant richness (mown/sprayed: 8.4; sprayed: 6.6 species/m2), native plant richness (mown/sprayed: 5.7; sprayed: 4.0 species/m2) or density of non-planted tree seedlings (mown/sprayed: 46; sprayed: 25 seedlings/m2). However, the study did report differences between treatments in the abundance of some individual plant species (statistical significance not assessed). For example, eastern common ragweed Ambrosia artemisiifolia was more abundant in mown/sprayed plots (20% of quadrats; 33% cover) than sprayed plots (0% of quadrats). Reed canarygrass was less abundant in mown/sprayed plots (80% of quadrats; 31% cover) than sprayed plots (100% of quadrats; 73% cover). Methods: Twenty plots were established in a canarygrass-invaded wetland. Twelve plots were mown in August 2002. All 20 plots were then sprayed with herbicide (Roundup®) in November 2002, and planted with tree/shrub seedlings (roughly 1 seedling/m2) in spring 2003. In August 2004, plant species and their cover were surveyed in ten 1-m2 quadrats/treatment, ignoring planted trees/shrubs.

    (Summarised by: Nigel Taylor)

  2. Use herbicide to control problematic plants: freshwater swamps

    A replicated, randomized, paired, controlled study in 2002–2005 aiming to restore swamps in three reed canarygrass Phalaris arundinacea stands in Wisconsin, USA (Hovick & Reinartz 2007) found that spraying the vegetation with herbicide typically increased plant species richness and diversity, and increased tree seedling density. After 1–2 growing seasons, overall plant richness was greater in sprayed than unsprayed plots in two of three comparisons (for which sprayed: 3.2–6.6; unsprayed; 1.9–2.3 species/m2; other comparison no significant difference). The same was true for overall plant diversity (data reported as a diversity index). However, native plant richness did not significantly differ between treatments in two of three comparisons (for which sprayed: 1.7–2.6; unsprayed; 1.3–2.2 species/m2; other comparison higher in sprayed plots). The density of non-planted tree seedlings was greater in sprayed plots in three of three comparisons (sprayed: 3–25; unsprayed: <1–4 seedlings/m2). For one of the three swamps, the study also reported data on the abundance of individual plant species (see original paper). Methods: Sixteen plots of varying size were established across three canarygrass-invaded wetlands. Ten plots (1–8 random plots/site) were sprayed with herbicide (Roundup®) in autumn 2002 or 2003. Six plots (1–4 random plots/site) were left unsprayed. All plots were planted with tree/shrub seedlings (roughly 1 seedling/m2) in spring 2003 or 2004. In August 2004, plant species and their cover were surveyed in ten 1-m2 quadrats/treatment/swamp, ignoring planted trees/shrubs.

    (Summarised by: Nigel Taylor)

  3. Physically damage problematic plants: freshwater swamps

    A controlled study in 2002–2004 aiming to restore a swamp in a reed canarygrass Phalaris arundinacea stand in Wisconsin, USA (Hovick & Reinartz 2007) found that ploughing after spraying herbicide increased plant diversity and richness more than spraying alone, but that ploughing had no additional effect on the number of tree seedlings. After two growing seasons, the vegetation was more diverse in a ploughed/sprayed plot than in plots that had only been sprayed (data reported as a diversity index). The same was true for overall plant richness (ploughed/sprayed: 11.3; sprayed: 6.6 species/m2). However, the treatments did not significantly differ in native plant richness (ploughed/sprayed: 5.5; sprayed: 4.0 species/m2), or in the density of non-planted tree seedlings (ploughed/sprayed: 56; sprayed: 25 seedlings/m2). The study also reported differences between treatments in the abundance of individual plant species (statistical significance not assessed). For example, common vervain Verbena hastata was more abundant in the ploughed/sprayed plot (100% of quadrats; 20% cover) than sprayed plots (40% of quadrats; 3% cover). Reed canarygrass was less abundant in the ploughed/sprayed plot (40% of quadrats; 18% cover) than sprayed plots (100% of quadrats; 73% cover). Methods: Nine plots were established in a canarygrass-invaded wetland. All nine plots were sprayed with herbicide (Roundup®) in November 2002, and planted with tree/shrub seedlings (roughly 1 seedling/m2) in spring 2003. One plot was also ploughed, before planting, in spring 2003. This plot was slightly higher and drier than the unploughed plots. In August 2004, plant species and their cover were surveyed in ten 1-m2 quadrats/treatment, ignoring planted trees/shrubs.

    (Summarised by: Nigel Taylor)

  4. Use prescribed fire to control problematic plants: freshwater swamps

    A replicated, randomized, controlled study in 2002–2004 aiming to restore a swamp in a reed canarygrass Phalaris arundinacea stand in Wisconsin, USA (Hovick & Reinartz 2007) found that burning after spraying herbicide increased plant diversity more than spraying alone, but that burning had no additional effect on plant richness or the number of tree seedlings. After two growing seasons, the vegetation was more diverse in burned/sprayed plots than in plots that had only been sprayed (data reported as a diversity index). The treatments did not significantly differ in overall plant richness (burned/sprayed: 9.3; sprayed: 6.6 species/m2), native plant richness (burned/sprayed: 6.3; sprayed: 4.0 species/m2) or density of non-planted tree seedlings (burned/sprayed: 21; sprayed: 25 seedlings/m2). The study also reported differences between treatments in the abundance of individual plant species(statistical significance not assessed). For example, eastern willow herb Epilobium coloratum was more abundant in burned/sprayed plots (70% of quadrats; 10% cover) than sprayed plots (40% of quadrats; 6% cover). Reed canarygrass was less abundant in burned/sprayed plots (80% of quadrats; 34% cover) than sprayed plots (100% of quadrats; 73% cover). Methods: Twelve plots were established in a canarygrass-invaded wetland. All 12 plots were sprayed with herbicide (Roundup®) in November 2002, and planted with tree/shrub seedlings (roughly 1 seedling/m2) in spring 2003. Four random plots were also burned, before planting, in spring 2003. In August 2004, plant species and their cover were surveyed in ten 1-m2 quadrats/treatment, ignoring planted trees/shrubs.

    (Summarised by: Nigel Taylor)

  5. Remove vegetation that could compete with planted trees/shrubs: freshwater wetlands

    A replicated, randomized, paired, controlled study in 2002–2004 in three freshwater wetlands in Wisconsin, USA (Hovick & Reinartz 2007) reported that removing invasive reed canarygrass Phalaris arundinacea either increased or had no significant effect on survival of planted trees/shrubs over 1–2 growing seasons. In 68 of 136 comparisons, plots from which canarygrass had been removed supported significantly higher survival rates of planted trees/shrubs (13–100%) than plots where canarygrass remained (0–73%). In the other 68 comparisons, plots from which canarygrass had been removed supported statistically similar survival rates (0–100%) to plots where canarygrass remained (0–100%), although there was a trend for higher survival in cleared plots in 46 of these comparisons. The effect of canarygrass removal depended on the tree/shrub species, site and removal treatment. In other words, most species responded significantly to canarygrass removal only as a result of certain methods or in certain sites (see original paper). Plots from which canarygrass had been removed before planting also typically had higher overall plant species richness and diversity, and contained more non-planted tree seedlings, than plots where canarygrass was not removed (see Actions: Physically damage problematic plants, Use cutting/mowing to control problematic herbaceous plants, Use prescribed fire to control problematic plants and Use herbicide to control problematic plants). Methods: In spring 2003 or 2004, seedlings of 23 tree and shrub species were planted into three degraded wetlands (roughly 1 seedling/m2). Reed canarygrass had been removed from some planted areas, but left in others (distribution of seedlings amongst areas not clear). Removal treatments involved spraying with herbicide in all three wetlands, and in one wetland additional burning, mowing or ploughing. Survival of all seedlings was monitored in September 2003 and 2004. Other plant species and their cover were recorded in August 2004.

    (Summarised by: Nigel Taylor)

  6. Directly plant trees/shrubs: freshwater wetlands

    A replicated study in 2002–2004 in three freshwater wetlands in Wisconsin, USA (Hovick & Reinartz 2007) reported variable survival of 23 planted tree/shrub species after 1–2 growing seasons, depending on numerous factors. Overall, survival rates ranged from 0% after one growing season to 100% after two growing seasons. Survival rates depended on the combination of species, site, time after planting, plot elevation/wetness, and whether/how invasive reed canarygrass Phalaris arundinacea was removed before planting. After two growing seasons, three species had 100% survival under one treatment: blackcurrant Ribes americanum, elderberry Sambucus canadensis and highbush cranberry Viburnum opulus var. americanum, planted where canarygrass had been sprayed with herbicide and the soil had been ploughed. Twelve species failed to survive under at least one treatment. Yellow birch Betula alleganiensis failed to survive under any treatment. Methods: In spring 2003 or 2004, seedlings of 11 tree and 12 shrub species were planted into three degraded wetlands (roughly 1 seedling/m2). Reed canarygrass had been removed from some planted areas, but left in others (distribution of seedlings amongst treatments not clear). Removal treatments involved spraying with herbicide, herbicide then ploughing, herbicide then burning, or mowing then herbicide. Survival of all seedlings was monitored in September 2003 and 2004.

    (Summarised by: Nigel Taylor)

Output references
What Works 2021 cover

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, mammals, 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 21

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 ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust