DOI: 10.5061/dryad.zpc866thp
title: Data from: Wildflower strip establishment supports beneficial ground-dwelling arthropods and pest control but has limited effects on weed seed control and spillover to adjacent fields

description: Recent arthropod declines in agricultural landscapes can threaten
 biodiversity and the provision of ecosystem services. Wildflower strips
 (WFS) represent popular measures to support biodiversity. Most studies
 investigated their effects on pollinators, whereas ground-dwelling
 arthropods are less studied. In addition, time after WFS establishment is
 a relevant factor, but most experiments are performed in a single season.
 Here, we evaluated the effects of WFS on ground-dwelling arthropods
 (carabids, spiders, and myriapods) and ecosystem services (pest and weed
 seed predation) across three years. Using a standardised experimental
 design with paired control and WFS margins in 12 fields, we sampled before
 and up to the first two years after WFS establishment while also assessing
 spillover into adjacent fields. Our analyses revealed that spiders, as
 well as total pest predation and predation by rodents, were enhanced in
 two-year-old WFS, whereas similar but weaker patterns were observed for
 carabid and myriapod species richness. Spillover patterns were weak, and
 only carabid species richness was enhanced in parts of the field
 neighbouring WFS. These results reinforce the important role of perennial
 WFS in supporting beneficial ground-dwelling arthropod groups while also
 highlighting that taxon-specific responses can hinder the design of
 general measures to support biodiversity on arable land.
description: <em>Study sites and experimental
 design</em> The study was performed between 2020
 and 2022 in the northeast of Prague, Czech Republic (50°7′–50°10′N,
 14°31′–14°34′W; mean altitude 252 m a.s.l), where we selected 12
 conventionally managed arable fields (areas ranging from 3.5 to 33.9 ha;
 Table S1; Figure S1a). Fields were managed conventionally by the VIN AGRO
 company and sown with cereals, sugar beet, oilseed rape, and mustard.
 Following a BACI approach (i.e., before and after design), within each
 field, two margins separated by at least 75 m (mean 397 m) were chosen for
 sampling arthropod and ecosystem services before and after sowing flower
 strips. In addition to the field margins (12 m from the original
 boundary), we also sampled the interior of the fields adjacent to both
 margins, at 36 and 60 m (see Venturo et al., 2024 for details), making a
 total of six transects per field. In 2020 (hereafter, before WFS
 establishment), both field margins were part of the arable fields, whereas
 in 2021, one of the margins was selected as a control margin, and farmers
 managed it as the rest of the field, whereas the second margin was used
 for sowing experimental wildflower strips. Wildflower strips were sown
 after the crop harvest in 2020. Half of them were established in early
 September 2020, and the second half were established in early April 2021,
 depending on the sown crops. WFS were 24 m in width, and their length
 varied according to the size and shape of individual fields (see details
 in Table S1). The seed mixture used for wildflower strips was composed of
 24 plant species and included three species of flowering cover crops, 17
 species of other flowering dicots (mainly Fabaceae, Asteraceae, Apiaceae),
 and 4 species of grasses (for the detailed seed mixture composition see
 Table S2). WFS were sown using 25 kg of seeds per ha and managed by mowing
 and removing biomass. In the first year after establishment, WFS were mown
 once during the peak summer, whereas in the second year, they were mown
 twice (late June and early October).<em> </em>
 <em>Arthropod and ecosystem services
 sampling</em> During the three study years, we
 sampled three groups of common ground-dwelling arthropods in arable
 fields, which are also relevant for ecosystem service provision: carabids,
 myriapods (diplopods and chilopods), and spiders. A 20 m transect,
 parallel to the field margin, was established at each transect. Arthropods
 were sampled using three pitfall traps per transect, separated by 10 m
 exposed for approximately 30 days (from mid-May to mid-June during the
 three years). Traps were made of a 0.5 l plastic cup (diameter 10 cm)
 covered by an aluminium roof (25 × 30 cm) and filled with 33% propylene
 glycol (diluted with water) as preservation fluid. After the exposure
 period, trap contents were filtered, and the material collected was stored
 in plastic bags in a freezer at -20°C until sorting. For each arthropod
 taxon, specialists identified specimens to the species level, and species
 richness and activity-density were calculated for each trap.
 To estimate pest predation rates, we used the artificial sentinel
 prey method (Lövei
 & Ferrante, 2017). Artificial caterpillars (25 mm long
 and 3 mm diameter) made of light green-coloured plasticine (® Smeedi) and
 glued to a small piece of reed were used as sentinel prey. Twenty
 caterpillars were placed at the ground level on each transect, separated
 by 1 m, and exposed for 48 hours in two sampling periods per year, late
 spring (May, hereafter spring) and early summer (June, hereafter summer),
 making a total of 8,640 exposed caterpillars. Caterpillars were taken to
 the lab in plastic tubes and visually inspected for predation marks using
 an optical stereo microscope. Predation marks were classified into three
 categories: insects, small mammals, and birds. To
 estimate weed seed predation rates, we employed the seed card method. Seed
 cards were made of rectangular pieces of sandpaper (5 x 10 cm) with 30
 seeds of <em>Taraxacum </em>spp. glued with a tasteless and
 odourless glue (Westerman
 et al., 2003). On each transect, six seed cards separated by 4 m
 were exposed for six to nine days (according to weather conditions) at the
 ground level, fixed with two nails (2,592 seed cards in total). Each year,
 seed cards were exposed during two sampling periods, late spring (May,
 hereafter spring) and early summer (June, hereafter summer). After
 exposure, seed cards were taken to the laboratory in separate envelopes
 and dried. Undamaged seeds were counted to calculate predation rates as
 the number of predated or missing seeds divided by the number of exposed
 seeds on each transect. To correct for variations in exposure times, daily
 predation rates were calculated as predation rates divided by the number
 of exposed days.
description: # Data from: Wildflower strip establishment supports beneficial
 ground-dwelling arthropods and pest control but has limited effects on
 weed seed control and spillover to adjacent fields Dataset DOI:
 [10.5061/dryad.zpc866thp](10.5061/dryad.zpc866thp) ## Description of the
 data and file structure ### Files and variables #### File:
 Data\_sets\_WFS.xlsx **Description:** The dataset includes multiple sheets
 with all the data used in the article. The metadata sheet includes
 detailed instructions for reading and interpreting the remaining tables.
 The field and transect locations sheet includes the latitude, longitude,
 and elevation of each transect within the study sites. Trap-level data of
 arthropod taxa are provided in the sheets Araneae, Carabidae, Diplopoda,
 and Chilopoda, and the values in each cell represent the abundance of each
 species (column) in a given trap (row), with empty cells representing no
 individuals. Pest predation and Weed seed predation include all ecosystem
 services measurements used in the analyses.  ##### Variables * Transect:
 transect ID within each field - Latitude: latitude of the transect *
 Longitude: longitude of the transect - Altitude: elevation of the transect
 * Field ID: Id of the study field * Treatment: Experimental treatment,
 either control or wildflower strip * Distance: Distance from field margin
 to sampling transect (12, 36, or 60m) * Pitfall trap: Number of pitfall
 trap in the transect * Year: Sampling year (2020, 2021, or 2022) *
 Predation: Presence (1) or absence (0) or predation marks in artificial
 caterpillars * insect: Presence (1) or absence (0) or predation marks by
 insects in artificial caterpillars * rodent: Presence (1) or absence (0)
 or predation marks by rodents in artificial caterpillars * bird: Presence
 (1) or absence (0) or predation marks by birds in artificial caterpillars
 * number: Number of artificial caterpillar or seed card in each transect *
 period: Sampling period (1st = spring; 2nd = summer) * days: Number of
 exposure days for seed cards * remaining: Number of non-consumed seeds in
 seed cards * total: Total number of seeds in seed cards * predated: Number
 of consumed seeds in seed cards * daily: Daily predation rate of seeds *
 sq_daily: Square root of daily predation rates of seeds ## Code/software
 No specific software or code is needed to view the data used in the
 article.