Heat tree/shrub seeds before sowing: freshwater wetlands

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

Effectiveness

5%
Certainty

28%
Harms

20%

Calculating overall effectiveness category

Background information and definitions

Heating seeds before planting can help to break seed dormancy and encourage germination. Seeds of some species (with physiological dormancy) must experience high temperatures before germinating, in order to break down chemicals that inhibit germination or stop the production of these chemicals. For other species (with physical dormancy), heat can increase the permeability of the seed coat to water and gases, which are essential for germination. For a database of seed dormancy class by species, see Baskin & Baskin (2014).

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

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

Study locations

Key messages

One study evaluated the effects – on trees/shrubs typical of freshwater wetlands – of heating their seeds before sowing. The study was in a laboratory in the USA.

VEGETATION COMMUNITY

VEGETATION ABUNDANCE

VEGETATION STRUCTURE

OTHER

Germination/emergence (1 study): One replicated, controlled study in a laboratory in the USA found that heating baldcypress Taxodium distichum seeds in a flame before sowing reduced their germination rate.

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, controlled study in 2004 in a laboratory in Florida, USA (Liu et al. 2009) found that heating baldcypress Taxodium distichum seeds in a flame reduced their germination rate. Heated seeds had a lower germination rate (0% germinated) than unheated seeds (47% germinated). Methods: In August 2004, sixty baldcypress seeds were planted into trays of growing medium. All seeds had been stored at 4°C for four months before the experiment started, and soaked in distilled water for 24 h before planting. Thirty seeds (three replicates of 10 seeds) had also been held in a gas flame for 3 sec before soaking.
Study and other actions tested
Referenced paper
Liu G., Li Y., Hedgepeth M., Wan Y. & Roberts R.E. (2009) Seed germination enhancement for bald cypress [Taxodium distichum (L.) Rich.]. Journal of Horticulture and Forestry, 1, 22-26.

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
Chill seeds of non-woody plants before sowing: freshwater wetlands Action Link	Likely to be beneficial	6	Synopsis Link
Prune roots of trees/shrubs before planting: brackish/saline wetlands Action Link	No evidence found (no assessment)	0	Synopsis Link
Physically damage tree/shrub seeds before sowing: brackish/saline wetlands Action Link	No evidence found (no assessment)	0	Synopsis Link