Add cover other than mulch before/after planting trees/shrubs: freshwater wetlands

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

35%
Certainty

32%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Planted vegetation may be damaged by hot, dry and bright conditions on bare wetland surfaces. Covers such as plastic mesh, sheets, or shelters for individual plants could ameliorate these factors and help planted vegetation to establish. The precise effect of covers may vary depending on the material used and how it is applied (e.g. to a large area vs individual plants; on the wetland surface vs suspended above the surface).

Related actions: Add cover other than mulch, other than to complement planting; Add surface mulch to complement planting; Use fences or barriers to protect planted areas from physical damage, e.g. with tree guards or breakwaters.

Study locations

Key messages

One study evaluated the effects, on vegetation, of adding cover other than mulch to freshwater wetlands planted with trees/shrubs. The study was in Australia.

VEGETATION COMMUNITY

VEGETATION ABUNDANCE

Tree/shrub abundance (1 study): One replicated, randomized, paired, controlled study in floodplain swamps in Australia found that covering plots with plastic or jute mats before planting native shrubs had no significant effect on their overall cover, one year later.
Individual species abundance (1 study): The same study found that covering plots with plastic or jute mats before planting swamp gum Eucalyptus camphora seedlings had no significant effect on swamp gum cover, one year later. Covering plots with mats also reduced cover of two problematic herb species.

VEGETATION STRUCTURE

Height (1 study): One replicated, randomized, paired, controlled study in floodplain swamps in Australia found that planted swamp gum Eucalyptus camphora seedlings reached a similar height, after one year, in covered and uncovered plots. Covers were plastic or jute mats.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated, randomized, paired, controlled study in 2014–2015 in two degraded floodplain swamps in Victoria, Australia (Greet et al. 2016) found that covering plots with plastic or jute matting before planting native shrubs and tree seedlings had no significant effect on their cover or height. One year after planting, plots with and without mats had statistically similar cover of native shrubs (mats: 7–14%; no mats: 4–8%) and swamp gum Eucalyptus camphora (mats: 11–22%; no mats: 7–11%). Swamp gum saplings were a statistically similar height in plots with and without mats (data not reported). Additionally, plots with mats had lower cover of problematic reed canarygrass Phalaris arundinacea and common reed Phragmites australis (4–28%) than plots without mats (73–99%). Methods: In February–March 2014, six 100-m² plots were established in each of two floodplain wetlands. All plots had been recently cut and sprayed with herbicide (to control reed canarygrass or common reed) and fenced to exclude large animals. Four plots (two random plots/site) received each cover treatment: plastic weed matting, jute matting, or no matting. All plots were then planted with native shrubs (1 plant/m²; species not reported), swamp gum seedlings (1 plant/2 m²) and understory herbs (3 plants/m²). Holes were cut in the matting to allow planting. Vegetation was surveyed in March 2015, in five 1-m² quadrats/plot.
Study and other actions tested
Referenced paper
Greet J., King E. & Stewart-Howie M. (2016) Plastic weed matting is better than jute or woodchips for controlling the invasive wetland grass species Phalaris arundinacea, but not Phragmites australis. Plant Protection Quarterly, 31, 19-22.

Please cite as:

Taylor N.G., Grillas P., Smith R.K. & Sutherland W.J. (2021) Marsh and Swamp Conservation: Global Evidence for the Effects of Interventions to Conserve Marsh and Swamp Vegetation. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Marsh and Swamp Conservation

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