Soak trees/shrubs before planting: freshwater wetlands

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

Effectiveness

34%
Certainty

20%
Harms

15%

Calculating overall effectiveness category

Background information and definitions

Soaking vegetation before planting might increase tissue water content, promote root growth and increase survival after planting (Pezeshki et al. 2005). An abundance of roots might help the planted vegetation to take up enough water during dry periods. Adventitious roots may grow from the stem, near the water line, and help with oxygen uptake if the site is flooded or saturated (Havens 1996). Studies do not have to be in flooded/saturated soils, as long as they involve wetland-characteristic species.

To be summarized as evidence for this action, studies must have explicitly compared the performance of soaked and unsoaked plants. Studies that simply report the performance of pruned 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: Soak seeds before sowing.

^{Havens K.J. (1996) Plant Adaptations to Saturated Soils and the Formation of Hypertrophied Lenticels and Adventitious Roots in Woody Species. Wetlands Program Technical Report No. 96-2. Virginia Institute of Marine Science, College of William and Mary.}

^{Pezeshki S.R., Brown C.E., Elcan J.M. & Shields, F.D. Jr. (2005) Responses of nondormant black willow (Salix nigra) cuttings to preplanting soaking and soil moisture. Restoration Ecology, 13, 1–7.}

Study locations

Key messages

One study evaluated the effects – on trees/shrubs typical of freshwater wetlands – of soaking them before planting. The study was in a greenhouse in the USA.

VEGETATION COMMUNITY

VEGETATION ABUNDANCE

VEGETATION STRUCTURE

Biomass/plant (1 study): One replicated, randomized, controlled study in a greenhouse in the USA found that soaking black willow Salix nigra cuttings before planting had no significant effect on the above-ground biomass of surviving seedlings, over the 48 days after planting.

OTHER

Survival (1 study): One replicated, randomized, controlled study in a greenhouse in the USA found that the effect, on survival, of soaking black willow cuttings before planting depended on the water regime after planting. However, all cuttings soaked for 15 days before planting died within 42 days of planting.

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, controlled study in a greenhouse in Tennessee, USA (Pezeshki et al. 2005) found that the effects of soaking black willow Salix nigra cuttings before planting depended on both the duration of soaking and soil moisture after planting. All cuttings soaked for 15 days died within 42 days of planting. Under permanently or intermittently flooded conditions, cuttings soaked for 7 days and unsoaked cuttings had statistically similar survival rates after 48 days (soaked: 100%; unsoaked: 86–100%) and shoot biomass over 48 days (soaked: 1.4–1.8 g/plant; unsoaked: 1.4–1.7 g/plant). Under well-watered conditions, cuttings soaked for 7 days had a higher survival rate than unsoaked cuttings after 48 days (soaked: 86%; unsoaked: 57%) but had statistically similar shoot biomass over 48 days (soaked: 1.0 g/plant; unsoaked: 0.5 g/plant). Methods: A total of 378 cuttings (30 cm long, 1 cm diameter) were taken from actively growing black willow trees and planted in pots in a greenhouse (dates not reported). Of these, 252 random cuttings had been soaked in aerated tap water before planting (for 7 or 15 days). The other 126 cuttings had not been soaked. After planting, cuttings were exposed to one of three soil moisture treatments (permanently flooded, flooded for 4 in every 14 days, or daily watering). Seven cuttings/treatment were harvested 0, 4, 10, 17, 42 and 48 days after planting, then dried and weighed.
Study and other actions tested
Referenced paper
Pezeshki S. R., Brown C. E., Elcan J. M. & Douglas Shields F. (2005) Responses of nondormant black willow (Salix nigra) cuttings to preplanting soaking and soil moisture. Restoration Ecology, 13, 1-7.

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?

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This Action forms part of the Action Synopsis:

Marsh and Swamp Conservation

Related Actions

Actions	Effectiveness	Category
Expose seeds to light before sowing Action Link	No evidence found (no assessment)	Synopsis Link
Plant vegetation into heavy containers Action Link	No evidence found (no assessment)	Synopsis Link
Apply root dip to trees/shrubs before planting: brackish/saline wetlands Action Link	No evidence found (no assessment)	Synopsis Link