Transplant or replace blocks of vegetation: brackish/salt marshes
Overall effectiveness category Awaiting assessment
Number of studies: 1
Background information and definitions
This action involves the introduction of vegetation as blocks or large sods, containing multiple individual plants. This technique might be used to introduce particular species to an already vegetated site, or to speed up the revegetation of a currently bare site. Blocks may be cut from a focal site, kept to one side during a disturbance, then replaced. Alternatively, blocks may be sourced from a separate donor site. When moving blocks from a donor site, it may be necessary to excavate the recipient site to avoid raising the soil surface.
Caution: This action inevitably causes damage to any donor site. Also, Transplanted blocks could contain invasive plants, animals or microorganisms. A possible solution to these problems is to use soil from healthy marshes or swamps that are earmarked for destruction. Using local donor sites could minimize the spread of invasive species, and make use of communities adapted to local conditions.
Effects of this action could be measured for the sods or vegetation overall (e.g. overall community composition of sods, or survival of sods) or for individual species or plants within the sods (e.g. height of the dominant grass species).
Supporting evidence from individual studies
A replicated, controlled, site comparison study in 2004–2007 of four areas of an estuarine salt marsh in New South Wales, Australia (Green et al. 2009) found that transplanting sods of the dominant marsh plant saltwater couch Sporobolus virginicus had no significant effect on plant community composition. After 3–4 years, the overall plant community composition was statistically similar in degraded areas planted with saltwater couch sods and degraded areas that had not been planted (data reported as a graphical analysis). Where saltwater couch was not transplanted, it spread from remnant patches in and around the study area. In 4 of 12 comparisons over three years, planted areas contained a plant community that was >70% similar to natural reference areas (vs 2 of 12 comparisons for unplanted areas). Methods: Between 2003 and mid-2004, four degraded areas of tidal salt marsh around a lagoon were restored using multiple interventions, including fencing to exclude vehicles and filling eroded patches with sediment. Two of these degraded areas were also planted with sods of saltwater couch (100 cm2; 1 m apart) cut from nearby natural marshes. Two additional areas of natural, undisturbed salt marsh were used for comparison. Plant species and cover were surveyed six times between July 2004 (after intervention) and April 2007. Each survey used fifty 1-m2 quadrats/area.Study and other actions tested