Species Rich Grasslands
What they are and why they matter
It's estimated that in less than a century, Britain has lost 97% of its species rich grasslands. These important habitats are not only valuable carbon stores, but home to thousands of specialist plants, insects and fungi. Remaining fragments of meadow are now vulnerable to development and forestry proposals - But what do they look like and how can we find them?
What are they?
Species rich grasslands boast a high diversity of wild plants and are found on land untreated with agricultural fertilisers. This means they are often restricted to small, inaccessible pockets such as field corners, steep slopes and woodland clearings.
Grasslands are important because wild flowers provide a valuable nectar source for pollinating insects, which in turn support healthy populations of other animals like birds and mammals. Grasslands also provide many ecosystem services such as flood mitigation.
Indicator Species
There are different types of species rich grassland, influenced by geology, water retention and soil type. For example, calcareous grasslands are typical of lime rich, rocky outcrops. Whilst rush pastures are found in waterlogged soils.
The different grassland types can be distinguished by the characteristic plants which grow in each. The purple flowered wild thyme pictured opposite, is associated with calcareous grassland. Whereas species like common knapweed, yellow rattle and birds-foot trefoil are found in neutral, lowland meadows.
Improved Grasslands
When grasslands are fertilised or re-seeded with a grass crop species, they become improved - evident by their bright green colour and poor diversity. Species such as rye grass and creeping buttercup quickly dominate and out compete smaller herbs.
Despite some of the threats posed by agriculture, grasslands do require a certain amount of grazing to remain species rich. Under and over grazing are common problems, therefore conservationists must work closely with farmers to protect sites.
Meadows are part of our cultural heritage and should be preserved for future generations. Locating and mapping the remaining 3% is therefore of the utmost importance - but how should this be approached? Currently, only half of Scotland has been surveyed for grassland, so there is a lot of ground to cover.
Grassland surveys
Detailed grassland surveys usually involve identifying all plants to species level within a randomly selected quadrat. The combination of species present, and in what percentage will then determine the grassland type.
This is usually performed by an experienced botanist which can be expensive and time consuming.
A new approach
Scottish Natural Heritage are testing a new method which aims to reduce the time needed for traditional surveying. This exciting project will use remote sensing techniques such as high definition aerial photography and machine learning, combined with existing habitat and species data to locate potential sites of lowland species rich grassland.
This method could potentially eliminate unsuitable areas of land, reducing survey costs. Its effectiveness will be tested in the Cairngorm National Park
