Threeruns Carabid dataset

This dataset contains information about Carabid adult species sampled using standard pitfall and subterranean traps. Each sampling point was geo-referenced. The total number of each Carabid species trapped was registered per sampling point. The sampling was carried out in three runs from the 20th of June to the 8th of August 2019 at Rothamsted Farm. A total of 10 margins were sampled through transects located perpendicular to the field edges.

Standard pitfall traps and subterranean traps were set using 70% ethanol 30% water mix, filled to 1/3 of the standard (200 ml) pitfall cup, and 1/4 of the subterranean (150 ml) pot.
Traps were run from the 20th of June to 8th of August 2019, in three runs; each consisted of a seven-day period.
Carabid adults were identified to species (Luff, 2007). Consensus tests were carried out with individuals processing samples. All runs of the experiment were subject to similar climatic conditions and constituted the same lifecycle period in terms of community assemblages, and as such were pooled for analyses. Samples that were spoiled damaged or incomplete (around 10 %) were not included in for analysis. Altogether, there were 224 traps from Run 1, 269 in Run 2, and 278 in Run 3. We used the standard proxy measure of activity density to account for abundance.
In the farm, the sampling was carried out along transects perpendicular to the field edge (where possible as dictated by field shapes) in each margin. Each sample point was geo-referenced.
Each field was split into three zones:
- M: margin or field edge (in the case of the control treatment).
- CE: crop edge (2–3 m from Margin or field edge).
- CC: crop centre (defined as a representative central point of the field at least 20 m from the field edge, in most fields 40–50 m).
In addition, two zones that extended back into the adjacent habitat (two-way transects) were also sampled: (i) adjacent habitat edge and, (ii) adjacent habitat centre. Where a field bordered an urban area, the adjacent habitat was not sampled. All transect groups ran parallel to field side boundaries for blocking, to minimise the effect from these.