Herb Robert onlimestone pavement
The botanical interest of limestone pavements is largely influenced by a combination of the structural diversity of the limestone and the level of grazing. Larger areas of limestone pavements, with a good range of rocky features, including grikes of different depths and widths will provide a greater variety of niche habitats for ferns and other specialised species. The plants which are most commonly associated with the pavements of the Yorkshire Dales are the ferns. These may include the maidenhair spleenwort, hart’s-tongue fern, rigid buckler-fern and brittle bladder-fern. Within the limestone pavement habitat there are a number of niches with their associated plants species.
Plants typical of rocky conditions include wall lettuce, biting stonecrop and rue-leaved saxifrage. The nationally more scarce species lesser meadow-rue is particularly associated with the limestone pavements in the Yorkshire Dales National Park.
Well developed pavements that receive only light grazing can develop vegetation on the surface of the clints. Plants which favour these conditions are light-demanding, grazing-tolerant and competitive limestone grassland species such as blue moor-grass, wild thyme, limestone bedstraw, common rock-rose and bloody crane’s-bill.
The sheltered, shaded conditions within grikes provide ideal habitats for many woodland understorey plants. The most abundant of these are dog’s mercury, ramsons, herb Robert and wood sorrel. Other less frequently occurring woodland species associated with limestone pavements include sanicle, wood anemone, enchanter’s nightshade and more rarely, herb-paris, lily-of-the-valley and baneberry.
In areas with reduced grazing pressure several scrub and tree species colonise pavements, including the native hawthorn, hazel, blackthorn, holly, ash, rowan and juniper and the introduced tree species sycamore. In the Dales these species generally only exist as occasional scattered trees.
To find out more about limestone pavement plant species in the Yorskhire Dales please follow the links provided.
Sources of information:
Thom, T (2005) Limestone Pavement Yorkshire Dales National Park Authority.
