What is Rush Pasture Habitat and why is it important?

Tree clearance in the uplands led to a rise in open moorland habitat, which was then grazed heavily by stock animals (particularly sheep who find rushes unpalatable) leaving a scattered mosaic of thick rush pasture habitat through grazed grassland. Rush pasture can present as species rich habitat or simply as clumps of rush plants through a field; while one is more beneficial to wildlife, even species poor rush pasture can be an important haven for animals like water voles.

Supported in its maintenance by the Rural Payments Agency and listed in the Biodiversity Action Plan priority habitats, rush pasture is recognised as a rare and important habitat type throughout the UK. However, Rush plants have not always been looked upon favourably and the problem of the infestation and subsequent management of rush in wet pasture has always been an issue for farmers. Rush plants have historical significance, they were gathered to stuff medieval mattresses, woven into mats for floors, stripped and used as candle wicks and had (and continue to have) many more interesting functions including some religious ceremonies. Once a much more abundant habitat, much of the UK’s rush pasture habitat has been steadily cleared over time with an estimated 8% left of its former coverage.

The species rich varieties of the habitat are also known as culm grassland in Devon and Cornwall, after the Culm Measures on which it is found, litter meadow in East Anglia for its historic use in bedding, and rhôs pasture in Wales. It occurs in poorly drained neutral and acidic soils, most commonly in the lowlands and upland fringe. Where present, it often serves to highlight areas of poor drainage, ditches, dips and wet flushes.

Importance for wildlife

Rush pasture habitat is at its most beneficial to wildlife when part of a structural mosaic, particularly when accompanied by areas of short or grazed grasses. At low level cover (less than 30% of the ground layer) it provides a hugely important breeding habitat for many of our threatened upland waders. Lapwings, curlews, redshanks, snipe, and reed buntings all rely on rush pasture as their main breeding habitat, as tussocks provide cover for nests and chicks. Wet rush pasture supports amphibians and reptiles in otherwise open, dry habitat and provides some protection from trampling as stock will preferentially graze around it. Species rich rush pasture provides important habitat for BAP priority insects like the Marsh fritillary butterfly (Eurodryas aurina).

Water voles, particularly in the uplands, rely on the patches of continuous rush cover along watercourses for food and cover for their burrows and feeding activity. Again, as livestock rarely graze amongst the rushes and choose to cross the watercourses at focused, set points, they also serve to protect the voles and their burrows from trampling.

Management of rushes

The management of land for farming is what created the abundance of rush pasture that we see today, but it is now reliant on continued management for its survival.

Management can be tricky, if left unchecked rushes can invade grassland and make it unproductive for farmers and wildlife. There are several methods available to control rushes including cattle grazing/trampling, topping, cutting, flooding and the use of herbicides. In areas where breeding waders are present, rushes are generally cut after the last chicks have fledged- usually late August. However, poached, wet land tends to be the most productive for reseeding rushes; together with the fact that these areas are harder to cut manually, means that we often see an increased rush cover on the edges of watercourses. This creates the perfect buffer zone of long vegetation on the edge of the watercourse to protect from grazing for water voles- who’s above ground activity goes late into the autumn.

For more on why upland habitats are so important for water voles, have a read of Elliot’s blog here.

All images by Emily Marshall.