Information Improving Green Spaces for Wildlife

Content

UK Habitat Classifications

East Devon District Council owns areas of undeveloped green spaces across the district that fit in with different UK Habitat Classification categorisations. Although the majority of these areas of land are small and are located in urban areas, such as small green spaces in housing estates or in parks and gardens, they have all been categorised as Primary Habitats to fit in with UK Habitat Classification criteria, despite many of these areas either being predominantly occupied by less valued plant communities, or those areas, which we call wildlife improvement areas, only being able to support low density populations of more valued plant species due to long-term ‘cut and drop’ maintenance methods – that would not allow their classification as Primary Habitats.

Also, generalisations have been made, based on typical plant species informally observed, with regards to habitat types in wildlife improvement areas. This is due to a current lack of habitat survey evidence in those areas, and the UK Habitat Classification for grassland types referring to much larger tracts of land that have been allowed long-term development with minimal human intervention and, subsequently, have high populations of more valued, high biodiversity populations that support nature to a much higher degree.

1. Grasslands
2. Hedgerows
3. Broadleaf Mixed and Yew Woodland

Grasslands

Grasslands are defined as covering land areas that are not waterlogged and have more that 75% cover of herbaceous species, most of which are grasses. The existence and the proportionality of grassland habitat species will depend on the type of grassland.

Calcareous Grasslands

Calcareous grasslands cover just 3.1% of grasslands in the East Devon Area of Outstanding Natural Beauty, which is less than half the total of neutral grasslands. These rare grasslands (in the south-west) form on soils that have higher pH levels than 7, which means that the soils are base/alkaline. The underlying chalk or limestone dominates the soil, and the overlying plants have had to adapt to the highly alkaline conditions, which are not suitable for most plants. However, calcareous grasslands are some of our richest and diverse grasslands for wildflowers, which favour the dry conditions resulting from the high levels of drainage. Rainfall quickly drains through these grasslands and into the bedrock, forming underground channels and caves. The more rainwater becomes acidified by higher levels of carbon dioxide in the atmosphere, the quicker that bedrock under calcareous grasslands becomes eroded, which incrementally favours plants that like drier conditions, such as grasses and wildflowers.

Calcareous grasslands are usually managed as extensive grazing pasture rather than as hay meadows due to the site conditions, such as steep slopes, rock outcrops and shallow soils that are prone to desiccation during the summer months.

Acid Grasslands

Acid grasslands are dominated by grasses and herbs on a range of lime-deficient soils that are derived from acidic bedrock or from superficial deposits, such as sands and gravels. Such soils usually have a low base status, with a pH under 5.5. This level of acidity does not lend itself to high levels of diversity. EDDC-owned Jubilee Field in Budleigh Salterton is a rare coastal heath grassland. See below.

Neutral Grasslands

Neutral grasslands do not meet the definitions of either calcareous grassland or acidic grasslands. Neutral grasslands overly a range of neutral soils, usually with underlying soil pH ranges from mildly to strongly acidic: pH 6.5 to pH 4.5. Generally, these soils tend to be clay and loam. Neutral grasslands are usually used for species-rich hay meadows and for grazing pasture.

Neutral grasslands are extremely widespread in UK lowlands and constitute 7.2% of grasslands in East Devon. They can be identified by the presence of rye grass at a level that is under 30% of the total grass species, and the presence of between 9 and 15 other species of plants. These low levels of rye grass make it more feasible to sow wildflowers to improve biodiversity levels – which then has the potential to change the classification of the grassland.

Modified Grasslands

Modified (Improved) grasslands are created, in the context of East Devon’s grass swards, by former long-term land management practices by grounds maintenance teams that reduces biodiversity by enabling the monopoly of fast-growing species, such as rye grass and white clover, which can tolerate regular ‘cut and drop’ maintenance – at the expense of so many other species – so that they dominate. This abundance of strong and fast-growing species makes it difficult to increase the biodiversity by adding wildflowers without removing the turf because the growth of rye grasses will soon out-compete slower growing meadow wildflowers, such as in The Green, in Budleigh Salterton. See below. However, because these modified grassland areas were recently removed from regular maintenance schedules, the cycle of regularly nutrifying the soil by the decomposition of arisings from cut and drop mowing, biodiversity levels will naturally improve over time, as grasses lose their strength and vigour. When evidenced, these areas will be targeted for wildflower sowing.

Wildflower sowing will be carried out on several wildlife improvement areas across the district each year when wildlife improvement areas’ land and fauna conditions become appropriate.

EDDC’s wildlife improvement areas have been removed from regular maintenance schedules, other than the regular mowing of boundary cue-to-care lines, as well as any other mowing set up for an area, such as pathways or picnic areas on appropriate sites. However, these regularly mown areas within or around a designated wildlife improvement area are not included in the wildlife improvement area.

Depending on seasonality and the characteristics of each site, grounds teams will mow wildlife improvement areas up until the end of March. Then, in October, after allowing each wildlife improvement area to develop throughout the year, a contractor will cut and collect the larger, more open wildlife improvement areas, whilst grounds teams will cut and collect the smaller wildlife improvement areas at the same time with the new Amazone Profihopper ride-on mowers that are designed for cutting and collecting long grass and wildflowers.

Hedgerows

A maintained hedgerow is defined as a line of shrubs that have the base of the plants’ leaf canopies less than 2 metres from the ground so that the woody, linear landscape feature as a whole appears as a shrubby hedgerow – despite the fact that many of the plants contained within the hedgerow would become trees with the cessation of management. Hedgerows in better/healthier conditions have their bases less than 0.5m from the emergence of leaves.

Hedgerows range in form and composition based on the intentions for their use, from containing just a few plant species to a rich mixture of shrubs and trees. In urban areas, hedgerows tend to be used functionally to mark a landscape or garden boundary, whereas in rural areas, hedgerows were traditionally used to retain stock in fields. Coastal hedges contain a much higher proportion of blackthorn due to its salt tolerance. Until recently, these ancient hedgerows tended to be the most biodiverse. However, recent initiatives by community groups and EDDC staff have created hedgerows that also have elevated levels of biodiversity. The number of highly biodiverse native hedges is increasing. The Woodland Trust have led on providing local authorities and community groups with gratis native hedgerow packs. A hedgerow containing more than 80% native or naturalised (recorded in the field in the UK before 1500 CE) plants is classed as a native hedgerow.

Hedgerows with low diversity levels of the shrubs therein have received biodiversity increases by removing their bases from regular maintenance and the addition of hedge/woodland wildflowers, such as in Seaton cemetery. See below.

EDDC-owned hedgerows are maintained each autumn so as to provide as little disruption to nature as possible.

Broadleaf Mixed and Yew Woodland

This type of area is dominated by trees that grow taller than 5m in height. It excludes hedgerows but includes native and non-native tree species that have a canopy cover of more than 25%. Although this vegetation will have some evergreen tree species, such as yew, most of the trees therein will be hardwood and deciduous.  

Most broadleaf and mixed yew woodlands, or segments thereof, are Lowland mixed deciduous woodland largely occur with well-defined boundaries, such as within enclosed landscapes. These woods tend to be small; less than 20ha. Often, there is evidence of past coppicing, particularly on moderately acid to base-rich soils. There is great variety in the species composition of the canopy layer and the ground flora, and this is reflected in the range of tree species. Quercus robur (English Oak) is generally the most common oak present (although Quercus petraea (Sessile oak) may be abundant locally) and may occur with virtually all combinations of other locally native tree species.

Streetscene is increasing the coverage of broadleaf mixed and yew pocket woodlands by planting whips (small trees) each winter in areas that were, until the planting, regularly maintained (mown and strimmed) by grounds teams. This not only means that these newly planted areas are no longer releasing regular carbon via emissions from maintenance equipment, but also absorbing atmospheric carbon dioxide, a major climate change – and will do so for a long time to come.