Grassland: Selecting indicators of success for grassland enhancement (TIN050)

Indicator species (cont...)


If group 1 species are being introduced to a suitable site you should expect most or all of them to colonise and persist. You should expect a reasonable proportion (50% or more) of group 2 species to colonise and persist given optimum management. You should expect few group 3 species to colonise unless conditions including subsequent management were ideal.

A target should be set for the year following the initial enhancement work. Many of the added species, particularly those in group 1, should be apparent (vegetatively) in the first year following hay-spreading or over-sowing. Others such as common birds-foot trefoil and the group 2 species are sometimes slower to become frequent but would be expected to have at least a limited presence in the first year.

If the site and management are suitable they should increase in frequency through the lifetime of the agreement. Thus species richness/composition indicators of success for year five should be more demanding than those in year one. This will test the agreement as herbs can decline after an initial flush of abundance if the soil is too rich and/or the management favours competitive species. Note, the decline of some group 1 species in favour of species from other groups would be beneficial rather than detrimental.

Targets that meet the definitions of the various BAP grassland types in the FEP Handbook and should be achievable within five years are:

  • Acidic grassland: one of the listed indicator species is frequent and another three at least occasional in the sward.
  • Calcareous grassland: two of the listed indicator species are frequent and another three at least occasional in the sward.
  • Neutral grassland: two of the listed indicator species are frequent and another two at least occasional in the sward.
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