Apply root dip to non-woody plants before planting: brackish/saline wetlands

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

Effectiveness

10%
Certainty

27%
Harms

15%

Calculating overall effectiveness category

Background information and definitions

Before planting marsh or swamp plants, the roots could be dipped in a substance to retain moisture (e.g. mud or water-retaining gels) or stimulate growth (e.g. plant hormones). These dips may improve survival and/or growth of the planted vegetation. This action does not include root dips involving fungi.

To be summarized as evidence for this action, studies must have explicitly compared the performance of treated and untreated plants. Studies that simply report the performance of treated plants are not summarized here. Studies do not have to be in flooded/saturated soils, as long as they involve wetland-characteristic species.

Related actions: Add root-associated fungi to plants before planting, including via a root dip.

^{Baskin C.C. & Baskin J.M. (2014) Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination, Second Edition. Academic Press.}

^{Small C.C. & Degenhardt D. (2018) Plant growth regulators for enhancing revegetation success in reclamation: a review. Ecological Engineering, 118, 43–51.}

Study locations

Key messages

One study evaluated the effects – on emergent, non-woody plants typical of brackish/saline wetlands – of applying a non-fungal root dip before planting. The study was in the USA.

VEGETATION COMMUNITY

VEGETATION ABUNDANCE

Individual species abundance (1 study): One replicated, randomized, paired, controlled study on mudflats in the USA found that root-dipping smooth cordgrass Spartina alterniflora before planting had mixed effects on cordgrass density after 1–2 growing seasons, but never increased it.

VEGETATION STRUCTURE

Height (1 study): One replicated, randomized, paired, controlled study on mudflats in the USA found that root-dipping smooth cordgrass Spartina alterniflora before planting had mixed effects on cordgrass height after two growing seasons.

OTHER

Survival (1 study): One replicated, randomized, paired, controlled study on mudflats in the USA found that root-dipped smooth cordgrass Spartina alterniflora plants typically had a lower survival rate, after one growing season, than plants that had not been root-dipped.

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 1976–1977 on two intertidal mudflats in Texas, USA (Tanner & Dodd 1985) found that applying root dip to smooth cordgrass Spartina alterniflora before planting typically reduced survival after one growing season, but had mixed effects on cordgrass density and height after 1–2 growing seasons. After one growing season, dipped cordgrass had a lower survival rate than undipped cordgrass in five of six comparisons (for which dipped: 3–19%; undipped: 39–85%; other comparison no significant difference). After 1–2 growing seasons, cordgrass density was statistically similar under both treatments in 7 of 12 comparisons (for which dipped: <1–191 shoots/m²; undipped: <1–168 stems/m²) but was lower in plots planted with dipped cordgrass in the other five comparisons (dipped: 1–38 stems/m²; undipped: 21–252 stems/m²). Finally, after two growing seasons, cordgrass shoots were of statistically similar height under both treatments in three of six comparisons (for which dipped: 117–120 cm; undipped: 112–122 cm) but taller in plots planted with dipped cordgrass in two comparisons (dipped: 132–139 cm; undipped: 110–119 cm) and shorter in plots planted with dipped cordgrass in the final comparison (dipped: 84 cm; undipped: 122 cm). Methods: In July 1976, thirty-six 12.5-m² plots were established across two intertidal mudflats. Smooth cordgrass (20–100 cm tall) was transplanted into each plot (50 plants/plot, 50 cm apart. For half of the plots (9 random plots/mudflat), cordgrass was dipped into commercial root dip (Algenura-a; designed to increase water uptake) for 15 min immediately before planting. Cordgrass survival and density were recorded in October 1976. Cordgrass density and flowering shoot height were sampled in November 1977.
Study and other actions tested
Referenced paper
Tanner G.W. & Dodd J.D. (1984) Effects of phenological stage of Spartina alterniflora transplant culms on stand development. Wetlands, 4, 57-74.

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

Related Actions

Actions	Effectiveness	Studies	Category
Physically damage tree/shrub seeds before sowing: brackish/saline wetlands Action Link	No evidence found (no assessment)	0	Synopsis Link
Heat seeds of non-woody plants before sowing: freshwater wetlands Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Soak seeds of non-woody plants before sowing: brackish/saline wetlands Action Link	No evidence found (no assessment)	0	Synopsis Link