Metadata for 'Data from: Spatiotemporal isolation of oilseed rape fields reduces insect pest pressure and crop damage'

We studied the effects of different landscape parameters on three spatial scales on the densities of pest flea beetles and crop damage at the cotyledon stage in 56 spring oilseed rape fields across five years. 
The landscape parameters investigated include the cover of non-crop habitats (forests and pastures) as potential overwintering sites, the distance to winter oilseed rape fields in the same year, the distance to spring oilseed rape fields in the preceding year, the landscape level crop diversity in the previous year and the edge-density in the surrounding landscapes. 
Flea beetles (Coleoptera, Alticinae) were collected with four pitfall traps in one observation plot established in each field and counts represent total catches for all four traps and sampling intervals combined. Crop damage was assessed in 10 or 16 (depending on the year) 0.5 m x 0.5 m squares per observation plot following the crop damage categories in Ekbom & Kuusk (2005), https://res.slu.se/id/publ/7184, at the end of cotyledon stage (~ BBCH 14). Values represent the average crop damage per observation plot. Landscape parameters were extracted from the official land-use maps provided by Lantmäteriet (Terrängkartan) at three radii (500 m, 1000 m and 2000 m) around the centre of the observation plots.
For further information, see methods in the publication Boetzl et al. (2023) Spatiotemporal isolation of oilseed rape fields reduces insect pest pressure and crop damage. Journal of Applied Ecology.

The data in the 'flea_beetles_and_crop_damage.csv' file have information on flea beetles and crop damages recorded in 56 fields ('site_ID') and landscape parameters in the landscapes surrounding these fields at three spatial scales. 169 rows.



site_ID: 					ID of the sampled field, combination of 'year' and 'site_nr' within the given year

year:						year the sampling was conducted

site_nr:					individual field number per year

buffer_distance:				radius of the circular landscape buffer around the centre of the oberservation plot in the field in meters

proportion_arable:				proportion of arable land within the given buffer radius (in percent)

proportion_pasture:				proportion of pastures within the given buffer radius (in percent)

proportion_forest:				proportion of forests within the given buffer radius (in percent)

proportion_urban:				proportion of urban land within the given buffer radius (in percent)

proportion_water:				proportion of waterbodies within the given buffer radius (in percent)

proportion_wetland:				proportion of wetlands land within the given buffer radius (in percent)

proportion_SOSR:				proportion of spring oilseed rape in the preceeding year within the given buffer radius (in percent)

proportion_WOSR:				proportion of winter oilseed rape in the study year within the given buffer radius (in percent)

distance_to_SOSR_previous_year:			distance between the oberservation plot and the nearest spring oilseed rape field in the preceeding year (centre to centre)
	
distance_to_WOSR_study_year:			distance between the oberservation plot and the nearest winter oilseed rape field in the study year (centre to centre)

edge_density:					total edge length within the given buffer radius

crop_shannon_previous_year:			Shannon crop diversity within the given buffer radius in the preceeding year

field_size_ha:					field size of the studied spring oilseed rape field in hectar

sowing_date:					date of spring oilseed rape sowing as day number in the year

distance_center_to_closest_field_edge:		distance from the centre of the observation plot to the closest edge of the spring oilseed rape field in meters

plot_length:					length of the observation plot in meters

plot_width:					width of the observation plot in meters

plot_area: 					area of the observation plot in square meters

mean_dmg_proportion:				spring oilseed rape cotyledon damage (measured as area of cotyledon damaged) as proportion (1 = 100%)

dmg_day:					day number in the year at which the damage was assessed (maximum crop stage was 14)

pitfall_trap_days:				total days pitfall traps were active in the given observation plot (i.e. all species count data were collected with this sampling effort)

fleabeetles_total:				total count for all flea beetles collected in the given trap days in the observation plot

Phyllotreta_sp:					sum of the total counts of all species of the genus Phyllotreta collected in the given trap days in the observation plot

columns 28 to 48:				total counts for individual flea beetle species / genera collected in the given trap days in the observation plot