How we added value

Biodiversity Survey & Design: sites of biodiversity assessment

The plant biodiversity survey was conducted along two stretches of highway: a 5 mile stretch of the A330 near Salisbury (46 ha) and  3.5 mile stretch of the A36 near Brickworth (36 ha). At both sites, 1m x 1m quadrats were surveyed at intervals as close to 0.5 miles.

Biodiversity Valuation: the Biodiversity Quality Calculator

Biodiversity is complicated and cannot be measured by using species richness data alone. Therefore, Ecosulis developed the Biodiversity Quality Calculator (BQC). By using the plant quadrant data to calculate a wide range of biodiversity measurements, the BQC could assess the biodiversity baseline along the two high way stretches.

Result: plant biodiversity

Roadside verges were patchy with tall ruderal and scrub species being recoded within over half of the quadrats. The habitat was assessed as species poor neutral grassland, due to the limited species diversity and the domination of perennial rye grass,  fescue and bramble scrub. Two positive indicator species (devils bit scabious and meadow vetchling) were rare.

Result: effects of seed mixes

Ecosulis provided a forecast in the change in biodiversity as a result of using different seed mixes. Based on the plant assessment, Ecosulis recommends seeding road verges with basic and special general meadow mixture. Whilst this does not provide an increase in the species, it would result in an increase in species rarity.

More Information

  • Recommendations for the type of seed mixture allow for a cost/benefit analysis which compares the different costs of the mixes against their relative biodiversity change. The forecast is based on the seed mix proportion provided by the manufacturer. It is anticipated that the actual take up will change slightly for each species, depending on the site conditions.
  • Ecosulis’ recommendations for ecological enhancement of road verges include: 1) native planting, particularly within areas of open grassland; 2) management of scrub areas, 3) rubbish removal with precautions and monitoring, 4) Long-term monitoring programme to provide future management decisions.


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