Saltmarsh restoration through flash re-creationprecipitation, and being drainedby evaporation and percolationinto the soil. In some areas ofmarsh the groundwater tablealso supplies fresh water andallows the development of moreorganic soils than the typical siltdominated sediments. Flashesare functionally important tothe marsh, not just because theysupport still-water communitiesbut also because they have adifferent ecosystem – typified bylow vegetation cover and highinvertebrate biomass. Owingto the gradual loss of waterfrom the pools, their marginalareas are often characterised bysparsely vegetated drawdownA digger working on flash re-creation. Bart Donatozones (areas of ground exposedas the water level drops) favoured by open-ground United States, it is rarely carried out in the UK,except on a small scale to facilitate wildfowling.invertebrates and wading birds.Similar measures have been adopted on theHistorically, at least on the saltmarshes ofContinent as part of recovery plans for coastalnorth-west England, many of these depressionsmarshes where restoration of wader communitieshave been drained by the installation of a footis the aim. On the Solway, the restoration ofdrain network – hand-dug ditches that allowwater gathered in the lowest points of the flashes a the water-holding ability of the flashes has beenreinforced by other methods aimed at enhancingdirect pathway to escape to the creeks through anwader productivity, including the developmentincision in the raised bank. This was done becauseof tailored grazing regimes to improve swardthe removal of temporary brackish pools, withstructure and the deterrence of terrestrialtheir bare drawdown zones, allows vegetationpredators via physical barriers.cover to increase, thereby providing a largerarea for grazing or turf-cutting. Drainage does,however, have a significant impact on the functionFlash restorationof the marsh surface. Instead of pools that areIn its simplest terms, flash restoration can befilled by large tides and rainfall, a system becomesthought of as plugging a leak and preventingestablished in which tides are able to reach thewater – derived from tide or rainfall – frommarsh more often (via the incisions in the levees),escaping the surface of the marsh. In our workbut the estuarine water and rainfall are lost aswe have employed two techniques, dependingthe tide recedes. As a consequence, rather than aon situation and constraints: the restorationpattern of infrequent saturation with long periodsof former flashes and the creation of artificialof water retention, the marsh is inundated moreones that function as natural flashes would.frequently but the water is then rapidly lost, oftenIn both cases, areas of past modification andwithin hours after a high tide.optimal areas for restoration have initiallyOver the past decade we have undertaken works been identified by analysis of LiDAR data andto restore a number of saltmarsh flashes on theaerial photography (particularly Google Earth).English Solway, particularly on Rockcliffe Marsh,In many instances, the variation in surfacethrough remediation or adaptation of drainagelevels between the creek-edge levees and theirchannels. Although this type of restoration isassociated flashes is minimal (between 10cmregularly implemented on saltmarshes in theand 20cm) and can be difficult to determine byConservation Land Management Summer 2022 | Vol. 20 No. 2 5
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