Mixed results of agri-environment schemes and options on arable farms in central and east England
Stevens D.K. & Bradbury R.B. (2006) Effects of the Arable Stewardship Pilot Scheme on breeding birds at field and farm-scales. Agriculture, Ecosystems & Environment, 112, 283-290.
Farmland birds have been declined in Britain for several decades due to changing agricultural practices. Agri-environment schemes are one option to try and reverse these declines. In 1998, the Arable Stewardship Pilot Scheme (ASPS) was developed to try and identify key on-farm practices that benefited wildlife. This study reports on some of the findings.
In April-June 1999 and 2003, a total of 84 farms (47 employing ASPS management options – ‘scheme farms’ and 37 managed conventionally) were surveyed for resident birds. Forty one farms were in East Anglia (parts of Cambridgeshire, Suffolk, Essex and Hertfordshire) and West Midlands (parts of Shropshire and Staffordshire).
Analyses were conducted at both the farm level and field level, with surveyed fields categorised by the type of intervention employed. Specifically, the following were examined:
- The use of set aside
- Uncultivated margins around intensive arable fields
- Grass buffer strips/margins around fields
- The use of wild bird seed mix
- Overwinter stubbles being left
- The use of uncropped, cultivated margins/plots
- The creation of beetle banks (planted strips designed to aid biological pest control)
- The use of conservation headlands (unsprayed headlands)
- A general reduction in pesticide or herbicide use
A total of 256 fields were surveyed, 196 arable and 60 pastoral.
ASPS sites generally (farm-scale analysis)
Only three species (two in East Anglia, one in the West Midlands) showed a significant positive response to the introduction of agri-environment schemes, whilst one showed a significant negative effect.
Meadow pipits Anthus pratensis, carrion crows Corvus corone and reed buntings Emberiza schoeniclus either declined less or increased on farms under agri-environment schemes, compared to ‘control’ farms, conventionally managed. Corn buntings Miliaria calandra declined significantly faster on agri-environment scheme farms.
Overall, only six species showed any positive response (significant or not) in both regions, ten showed negative responses in both and 12 showed a positive response in one region and a negative response in the other.
Due to a large number of null counts, only four fields-nesting species (skylark Alauda arvensis, corn bunting, lapwing Vanellus vanellus and yellow wagtail Motacilla flava) and eight boundary-nesting species (chaffinch Fringilla coelebs, dunnock Prunella modularis, greenfinch Carduelis chloris, linnet Carduelis cannabina, reed bunting, tree sparrow Passer montanus, whitethroat Sylvia communis and yellowhammer Emberiza citrinella) could be analysed at the field scale.
Set aside, wild bird seed mix and overwinter stubbles
The analysis did not distinguish between set aside fields, wild bird seed mix and overwinter stubbles and classed all three as interventions aimed at providing seeds for farmland birds. These interventions were strongly and positively associated with skylark and linnet abundance, but none of the other 12 species analysed.
Uncultivated margins and planted grass margins around agricultural fields
The maximum width of grass margins (the study did not distinguish between uncultivated and planted margins) around fields was strongly positively associated with four out of twelve farmland bird species analysed. These were skylarks, chaffinches, whitethroats and yellowhammers
Uncropped, cultivated margins/plots
Only reed buntings were strongly (and positively) associated with uncropped, cultivated strips.
Beetle banks were not associated strongly (positively or negatively) with beetle banks.
Conservation headlands and a general reduction in pesticide or herbicide use.
These chemical input-reducing interventions were not separated in the analysis.
Reduced chemical input was strongly and positively associated with five species (one field-nesting and four boundary-nesting species): corn bunting, chaffinch, greenfinch, whitethroat, and yellowhammer.
Overall, four species did not show strong positive or negative associations with any interventions: lapwing, yellow wagtail, dunnock and tree sparrow.
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