Examples of grassland habitat in Oxfordshire
Below is a brief summary of the different grassland habitats you can find across Oxfordshire. Some of the species you may find in each of these habitats are also listed under each heading. However, please note that the species listed aren't ones that you are absolutely guaranteed to see as many will depend on the conditions at the time, such as how wet the grassland is, or what the neighboring habitats are.
Indicator Species
Some of the plants listed under each grassland are indicator species for that habitat and are labelled as such. This means that the presence of these plants suggests that the area is a particular grassland type as they favour particular conditions e.g. oxeye daisy is an indicator of lowland meadow. However, many wildflowers are found across multiple types of unimproved grassland; i.e. many of the plant species that are found in unimproved, calcareous grassland also are found in dry, acidic grassland. You can find a list of plant indicator species and their associated grassland habitats in the appendix of PlantLife's 'Managing grassland verges: a best practise guide'.
Lowland Meadows (Neutral grassland):
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Image: Lowland Floodplain Meadow (Little Wittenham - Oxfordshire)
Species you might see
In Oxfordshire we have some exceptional lowland meadows, many of which are designated and protected sites. These habitats are dependent on low fertility soils and traditional management methods. Neutral grasslands are flower rich, and are important for invertebrates and ground nesting birds such as the skylark. These grasslands are usually found on clay soils and are sensitive to changes in hydrology and nutrient status.
Types of neutral grassland in Oxfordshire include:
- Floodplain Meadows (can be managed as a hay meadow but the high-water content can change the species mix and botanical composition)
- Traditional hay meadows
- Scarce flood meadows, e.g. Oxford Meadows SAC and Long Mead Meadow at Eynsham.
The British National Vegetation Classification (NVC) is a system of classifying habitats according to the vegetation they contain. Unimproved neutral grassland, including hay meadows, is known under the National Vegetation Classification (NVC) system as MG5 grassland, and used to be considered the predominant type of old meadow and pasture in the lowlands across the UK.
Lowland Calcareous Grassland:
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Image: Calcareous Grassland (Oxfordshire)
Species you might see
Calcareous grassland meadows have dominated the chalk hills of Southern England for many centuries, and were widespread until the 1940s, covering many of the steeper slopes in the Chilterns, the North and South Downs, Salisbury Plain and the Lincolnshire and Yorkshire Wolds. They are now a relatively rare habitat with less than 41,000 ha remaining in the lowlands.
Lowland calcareous grassland is a key habitat in Oxfordshire and is found across much of the Chilterns and Cotswolds. Oxfordshire’s calcareous grassland meadows support nationally important rare plants including the bulk of the UK populations of downy woundwort, meadow clary, and early and Chilton gentian species. They are also important sites for invertebrates, particularly for butterflies. Two of Oxfordshire’s rarest butterfly species, the Adonis blue and silver-spotted skipper, are chalk-grassland specialists, as is one of the UK’s most threatened butterflies, the Duke of Burgundy - all three of these species can be found in the County.
Calcareous grasslands are associated with areas of chalk and limestone geology, and as such, are particularly sensitive to changes in nutrient status.
Swyncombe Downs SSSI (46.4 ha) is an exquisite part of the Chilterns Escarpment North Conservation Target Area (CTA), renowned for its chalk grassland, scrub and bird communities. The grassland includes some exceptionally species-rich grassland, comparable with the best examples in the country.
Click here to find out more about Oxfordshire's calcareous grasslands...
Acidic Grassland:
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Image: Acid Grassland (Lye-Valley Nature Reserve, Oxfordshire)
Species you might see
Acid grassland is a Priority habitat under the Oxfordshire Wildlife and Landscape Study (OWLS) which may initially seem surprising as it is not known for its species diversity. However, it is home to many specialist species and rarities that cannot grow anywhere else. Acid grassland is very sensitive to changes in soil pH. There are very few areas of this grassland in Oxfordshire, but a few pockets of it can be found:
- Dry Sandford and Hitchcope Pits (S. west of Oxford),
- Shotover (Download the Shotover leaflet to find out more)
- Lye Valley Nature Reserve
Acid grassland can grade into Heathland mosaic and so is often associated with Heathland habitats.
Lowland Heathland
Whilst often associated with acid grasslands, lowland heathland is not a grassland habitat as heather is the dominant species. There is little of this habitat in Oxfordshire, as it is associated with sandy soils such as those on the Mid-vale Ridge. Lowland heathland is generally not flower rich, but important for rare plants and invertebrates. Like acid grassland, it is also sensitive to changes in nutrient status.
Tussocky grassland:
Image: Tussocky grassland (Oxfordshire)
Species you might see
This grassland is created when there is little grazing or cutting and the species mix gets dominated by tussock grasses. It can be found across most geology types. This habitat is typically not wildflower rich but is important for many invertebrates and provides excellent shelter for small mammals, amphibians and reptiles.
What determines the type of grassland?
Thanks to its geological diversity, Oxfordshire has a wide mix of grasslands from the large areas of chalk downland in the Chilterns, North Wessex Downs and Cotswolds, to the floodplain meadows in the river valleys, as well as small pockets of acid grassland, heath and fen.
Around the river valleys is clay soil – this is claggy, retains flood water, and slows drainage. These soils are typical of floodplain grazing marsh /meadows.
Around the Chilterns there is chalk downland (chalk grassland). Chalk soils are more porous and fine-grained than limestone soils and both are more free draining than clay.
There is very little acid grassland / heathland / fen in Oxfordshire, which forms on sandy soils. There are small patches around edge of Oxfordshire e.g. Lye Valley and parts of Shotover Country Park (these aren’t on the geology map because they’re too small for this scale).
- The type of grassland is usually determined by the soil type and underlying geology of the area
- Not all grasslands are wildflower meadows
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