Soil properties of nesting sites of the ground-nesting wild bee Andrena vaga and corresponding uncolonized control areas

We recorded soil properties of 27 nesting sites of the solitary ground-nesting bee Andrena vaga within the city of Braunschweig, Germany, and compared them to uncolonized control areas, where no bee nests were found. The control plot had a size of 1 m² and was approximately 2-5 m away from the edge of the colonized area. General site conditions in the control regarding slope and exposure preferably matched the sample plot in the colonized area. In May and June 2021, three soil samples were taken within a 1 m²-plot, each in an area within the nesting sites, where a high nest density could be found, and the corresponding control using a drill core. Soil cores were subdivided into the depths of 0-15, 15-30, 30-45 and 45-60 cm and the three samples per depth were lumped for either the aggregation or the control, respectively. Combined samples were analysed regarding proportion of dry matter, soil skeleton, total carbon and nitrogen, as well as pH, conductivity, potassium, phosphorus, and soil texture. A detailed method description of the soil analyses can be found in the attached PDF document. The table includes columns for the Study site ID (both aggregation and control plots) Geolocation for each study site Plot type (aggregation & control) Depth of the soil sample Proportion of dry matter Proportion of nitrogen (N) Proportion of carbon (C) Carbon-to-nitrogen-ratio (C/N ratio) pH value Conductivity Available potassium (K2O) Available phophorus (P2O5) Weight of the total air dried soil sample Weight of the soil skeleton (> 2 mm) Weight of the sieved fraction (< 2mm) Proportion of soil skeleton Proportion of coarse sand (0.63 – 2 mm) Proportion of medium sand (0.2 – 0.63 mm) Proportion of fine sand (0.063 – 0.2 mm) Proportion of coarse silt (0.02 – 0.063 mm) Proportion of medium and fine silt (0.002 – 0.02 mm) Total proportion of sand (0.063 – 2 mm) Total proportion of silt (0.002 – 0.063 mm) Proportion of clay (<0.002)