Farmland Habitats Habitat Action Plan

Following considerable discussion, it was decided to rename the Arable Farming HAP 2002 to Farmland Habitats HAP. This now encompasses mixed farming, arable plants and farmland birds.

Arable Farmland is the most abundant habitat in Wiltshire, and represents about 50% of the county’s area. The county contains some of the most biologically diverse arable land in Britain, and is particularly important for rare arable plants and farmland birds. 33 Important Arable Plant Areas (IAPAs) have been identified in Wiltshire, illustrating its importance for rare arable plant biodiversity.

Species associated with farmland habitats

There are many species that depend on farmland habitats, and although no quantitative data exists, it has been suggested that around 700 species of invertebrates and some 70 species of birds are dependent upon this habitat, along with 150 species of flowering plants.

Extensive research has shown that the declines that have been exhibited over the past 50 years in many farmland species have largely been caused by changes in agriculture, primarily driven by changes in government policy. There have also been changes in cropping practices including a shift from spring to autumn cultivation, which has reduced the amount of over-wintered stubble, an important foraging habitat for farmland birds.

Many farms have become specialised, resulting in a loss of habitat diversity, which many species, particularly birds and mammals such as Brown Hare, need to survive.

The widespread use of broad-spectrum herbicides has meant that the overall abundance and diversity of farmland flora and fauna has been greatly reduced. One of the major factors that resulted in the slowing in decline of farmland birds at the end of the 1980s was the introduction of set-aside. However, set-aside land is now likely to be lost on a large scale, as a result of the EU’s decision to remove the requirement on farmers for compulsory set-aside areas and high grain prices.

Data collected between 1970 and 1999 from the Common Birds Census and the BTO/JNCC/RSPB Breeding Birds Survey reveals the decline in particular farmland bird species Tree Sparrow 95%, Corn Bunting 88%, Turtle Dove 71%, Grey Partridge 79% and Lapwing 51%.

In 2006, Defra added “Butterflies on Farmland” to its list of Arable Biodiversity indicators. The abundance of butterflies on farmland sites has fallen by nearly a fifth over the last 16 years, with specialist species as a group (which includes species such as Adonis Blue and Marsh Fritillary) declining to a low point of 29% in 2001 (www.defra.gov.uk/wildlifecountryside/biodiversity/biostrat/indicators/index.htm).
Since 2001 there has been a modest recovery in specialist species, but recent trends are uncertain. Some species however, such as Chalkhill Blue and Silver-washed Fritillary appear to be doing well. In 2006 both of these species produced their highest index since monitoring began in 1976, and both have now been removed from the UK BAP Priority Species List.

Actions have been included in the Farmland Habitats Habitat Action Plan for both the Brown Hare, Lepus europaeus, and the Harvest Mouse, Micromys minutus. The Harvest Mouse has been added to the new UK BAP Priority Species List and the Wiltshire Mammal Group is working to find out more about its distribution in Wiltshire for the Action Plan.

Progress since 2002

The WBAP 2002 target for increasing the number of breeding pairs of Tree Sparrows to 210 was in fact exceeded to 280 breeding pairs between 2002-2003.
In 2005-2006 Arable field margins were sown with varieties to benefit butterflies, small mammals and other invertebrates, wild birds and game birds.

Subsequent surveys undertaken revealed increases in butterfly populations. The UK BAP Butterfly species Small Heath, Small Blue, Dingy Skippers and Marsh Fritillaries were also seen on arable field margins.

The Ministry of Defence (MoD) has significantly increased the numbers of the “Pheasant’s-eye” flower on the Salisbury Plain Training Estate – one of the last refuges for this rare native plant.

A working group has been set up, to take the Farmland Habitats Habitat Action Plan forward. This will maintain continuity from the original working group (led by Tim Frayling) which was very successful in implementing the original Farmland Action Plan. The group will be chaired by Simon Smart from Black Sheep Countryside Management, and meet twice a year.