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

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Share Tweet Email

View assessment score

How is the evidence assessed?

Effectiveness

50%
Certainty

30%
Harms

4%

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 brackish/saline wetlands planted with trees/shrubs. The study was in Mexico.

VEGETATION COMMUNITY

VEGETATION ABUNDANCE

VEGETATION STRUCTURE

OTHER

Growth (1 study): One controlled study on a sandflat in Mexico reported that planted black mangrove Avicennia germinans seedlings grew more in height, over six months, when shaded with black mesh than when not shaded.

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 controlled study on a saltflat in western Mexico (Flores-Verdugo et al. 2015) reported that planted black mangrove Avicennia germinans seedlings grew faster when shaded than when exposed. Statistical significance was not assessed. Over six months, the height of seedlings planted in a partially-shaded area increased by 0.20 mm/day (from 7.1 cm when planted to 11.0 cm after six months. Meanwhile, the height of seedlings planted in unshaded areas increased by only 0.03–0.09 mm/day (from 6.5–7.2 cm when planted to 7.8–8.5 cm after six months). Methods: In August–September (year not reported), 600 nursery-reared black mangrove seedlings were planted alongside four excavated tidal channels on a bare saltflat. Seedlings were 50–100 cm apart. The 150 seedlings alongside one channel were shaded with black mesh, which blocked 50% of incoming light. The height of surviving seedlings was recorded for approximately six months.
Study and other actions tested
Referenced paper
Flores-Verdugo F., Zebadua-Penagos F. & Flores-de-Santiago F. (2015) Assessing the influence of artificially constructed channels in the growth of afforested black mangrove (Avicennia germinans) within an arid coastal region. Journal of Environmental Management, 160, 113-120.

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
Introduce nurse plants to aid focal trees/shrubs: brackish/saline wetlands Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Add upland topsoil before/after planting non-woody plants: freshwater wetlands Action Link	Unknown effectiveness (limited evidence)	3	Synopsis Link
Disturb soil/sediment surface before planting non-woody plants: freshwater wetlands Action Link	No evidence found (no assessment)	0	Synopsis Link