Work on Oceanic Wet Grasslands in Scotland – an update

2021 saw a continuation of our work in the Western Islands of Scotland, primarily funded by the Halpin Trust. We sent botanists and other field workers back to the Outer Hebrides last July to develop two aspects of the project.

We had previously gathered data from the wet grasslands that form the landward end of the machair system in the Western Isles of Scotland. These grasslands seemed to be very similar to wet floodplain meadows in England and Wales. We wanted to explore whether the hydrological drivers that help shape these grassland communities are similar to those we have studied in England, and whether these grasslands are different enough to those elsewhere that they could be considered unique to the Western fringes of Europe

In 2021 therefore, we established two more research sites, to sit alongside the field in which we installed dipwells and recorded quadrats in, in 2019 (Figure 1).  We also re-visited our first site to re-record the quadrats and to download the automatic loggers.

In addition, we arranged interviews with the crofters who manage these species-rich grasslands to understand how site management works, and their concerns and aspirations for the future. This work was carried out by Edinburgh University’s Dr Ann Bruce, who is running a related project on the role of livestock in providing resilient food systems in remote, upland regions

We have continued to analyse the botanical data from these sites and from similar ones elsewhere, to understand whether the plant communities we provisionally identified in 2019 are genuinely new, and if so, how widespread they are.

Oceanic wet grasslands map
Figure 1.  Areas targeted on the Outer Hebrides in 2021 for botanical survey, crofter interviews and new research sites.

What we have found so far

Conservation status of wet grassland communities in Scotland

The surveys undertaken by the FMP between 2018 and 2021, and the use of other historic data where available, have enabled us to identify new plant communities not found elsewhere in England and Wales. It is likely that these plant communities are local to the western edges of Europe and therefore rare internationally.

In order to confirm this however, the next stage of the work is to compare these data to similar data gathered from the Irish Republic and Northern Ireland. We hope to be able to do this in late 2022.

Table 1. A list of the new, provisional plant communities
Latin name Common name Code
Caltha palustris - Carex nigra grassland Marsh marigold - Common sedge grassland CaCn
Agrostis stolonifera-Bellis perennis grassland Creeping bent - Daisy grassland AgBp
Agrostis stolonifera-Carex flacca grassland Creeping bent - Glaucous sedge Fen AgCf
Carex nigra - Potentilla erecta - Rhytidiadelphus squarrosus grassland Common sedge - Tormentil - Springy Turf - moss grassland Fen
Carex nigra - Agrostis stolonifera - Senecio aquaticus grassland Potentilla anserina variant Common sedge - Creeping bent - Marsh ragwort community; Silverweed variant MG14N

The plant communities listed above have been mapped as covering over 60 ha following our surveys, compared to just over 100 ha of equivalent vegetation recorded in England and Wales. The Scottish resource therefore has UK-wide significance. The plant communities identified are specifically located along the west coast of Scotland. We plan to explore data from corresponding areas along the West Coast of Ireland, and possibly explore other western fringes of Europe, including Norway.

Summary of crofting interviews

All crofters expressed a deep and detailed knowledge of their land, how it has changed over decades, and they had a good knowledge of the birdlife on the croft. The area is important for a number of ground-nesting bird species, there are a number of environmental schemes for managing these bird populations, and the RSPB has a strong presence on the islands. A number of the crofters indicated they would be interested in understanding more about the characteristics of the plants on their crofts, both in terms of their impact on the grazing animals and their value in terms of biodiversity. However, while crofters were aware of the plant life on their crofts, they tended to have limited understanding of its value.

The three main threats to continuing environmentally-sensitive management of the Machair in North and South Uist would appear to be land abandonment, changes in subsidy regime and sea level rise.

Maintaining drains was seen as an important agricultural activity, but one that relied on group activity and therefore was declining in some areas. The ageing population of crofters, together with the difficulty for new entrants to crofting, poses the possibility of land abandonment in the future. However, the Scottish Crofters Federation suggests there is considerable unmet need for people wishing to access crofts. The crofters rely on subsidy payments to continue their management, and changes in subsidies may promote or discourage various options. Climate change, through the effect of sea level rise was identified by crofters as a future challenge.


The species-rich wet meadows recorded in this survey are the result of decades, if not centuries, of grassland management by the local crofting community. The taking of a hay crop in July/August followed by grazing of the aftermath through autumn, plus the maintenance of a network of field gutters and ditches to remove excess water after heavy rain, has resulted in a diverse community of plants supporting a range of other taxa and creating a visual spectacle in summer. This management system is important for the maintenance of the wildflower communities. It is also important that the wider hydrological system (involving groundwater seepage from the sand dunes) is not interrupted by development, or other activities.

Photo of Creeping bent - Glaucous sedge (Agrostis stolonifera - Carex flacca) grassland
Creeping bent - Glaucous sedge (Agrostis stolonifera - Carex flacca) grassland
Photo of Creeping bent - Daisy (Agrostis stolonifera – Bellis perennis) plant community
Creeping bent - Daisy (Agrostis stolonifera – Bellis perennis) plant community
Photo of Marsh marigold - Common sedge (Caltha palustris-Carex nigra) grassland
Marsh marigold - Common sedge (Caltha palustris-Carex nigra) grassland

Spring/Summer Newsletter 2022: All Articles


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