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II. 1998. The effects of arable field margin management on the abundance and species richness of Arancac (spiders).Ecography 21: 74-K6.The elTects of ten different management regimes on the abundance and speeies riehness of Araneae on pre-existing and newly expanded zones of field margins surrounding arable fields are eompared in a large-seale experiment condueled belween 1987 and 1991. Most of the management regimes involved varying the Liming and frequency with whieh the field margins were cut. There was no evidence of consistent temporal trends in the abundance and speeies richness of Araneae on either the existing or expanded zones of the field margins during the first four years of the experiment. However, lowesi numbers were recorded before expansion of the margins in 1987, and highest numbers in lhe final sample, in 1991. Araneae remained less abundant, and less species rieh, on the newly expanded ihan on the existing zones of the field margins four years after they were 'set-aside'. Culling reduced both abundance and species riehness. Regimes which ineluded culling in mid-summer had a greater impact which persisted for longer than did ihose involving cutting in spring and autumn. Removal of cut material was associated with lower species richness than leaving it in siui. Sowing the margins with a wild fiower seed mixture was associated with increased abundance and speeies richness of Araneae. Annual spraying with a broad-speelrum, non-persistent herbicide reduced the abundanee of Araneae but the elTeet was not detectable until several months after the applieation of the spray. Both the species richness and abundance of Araneae were positively correlated with a measure of vegetation height made on the field margins in September, on both the pre-existing and newly expanded zones of the margins. The extent to which management praetiees which benefit Araneae are compatible with both the management requirements for various other taxa. and the overriding constraint of effective pernicious weed control on field margins, is discussed.M. Baines, C. Hamhler, I'. J. Johnson (corre.spondcnee, pjohnson@ermine.o.x.ac.iik),