Microclimate in wood mould boxes and the saproxylic beetle fauna along urbanization gradients

The aim of our study was to disentangle the effects of the urban heat island (microclimate) and urbanization onto saproxylic beetle species. Besides dead wood, hollow trees serve as important habitat for saproxylic organisms. To study the saproxylic beetle fauna in a standardized way, we used wood mould boxes, which resemble hollow trees. The datasets describe the microclimatic temperatures in and around mulm boxes, and the sampled saproxylic beetle species in the boxes. For the temperature measurement, temperature loggers were attached in the wood mould of each box, on the wall inside each box, and on a tree next to each box. In total, we had 10 boxes in six different study cities, which where placed along an urbanization gradient. The temperature loggers measured from April-September 2022. The beetle sampling took place in 2020, where two pitfall traps were placed into each box, and thus, beetles were sampled from April-September 2020. Climate_data: This file describes the mean microclimatic temperature on plot level measured in and around wood mould boxes from mid April until mid September 2022. It contains 12 columns and 112 rows. City: 6 study cities (1: Linköping, 2: Motala, 3: Lund, 4: Göteborg, 5: Örebro, 6: Uppsala) Plot: Each city contains of 10 plots, where the wood mould boxes have been placed. Due to lost boxes, this number can vary between cities. Canopy openness: Canopy openness in [%] Logger location: 3 logger types per plot measuring microclimatic temperature (1: inside wood mould in boxes, 2: inside boxes, 3: outside boxes). Due to lost loggers, this this number can vary between plots. Distance to city center: Distance from plot to city center in [m] Number of hollow trees: Number of hollow trees in a 20 m radius around the boxes Urban forest cover_3000: Amount of urban forest in a 3000 m radius around the boxes Urban forest cover_1000: Amount of urban forest in a 1000 m radius around the boxes Urban forest cover_500: Amount of urban forest in a 500 m radius around the boxes Urban forest cover_100: Amount of urban forest in a 100 m radius around the boxes Urban structures_3000: Amount of urban structures in a 3000 m radius around the boxes Urban structures_1000: Amount of urban structures in a 1000 m radius around the boxes Urban structures_500: Amount of urban structures in a 500 m radius around the boxes Urban structures_100: Amount of urban structures in a 100 m radius around the boxes Regional climate 2022: Mean temperature per study city from April-September 2022 from SMHI Microclimate: Mean microclimatic temperature per logger across the season April-September 2022 Species_data: This file describes the number and abundance of sampled species per box. It contains 17 columns and 112 rows. Abundance: Total number of sampled saproxylic beetle individuals Species richness: Number of sampled saproxylic beetle species Microclimate: Mean microclimatic temperature across the three logger locations per plot Regional climate 2019: Mean temperature per study city from April-September 2019 from SMHI Species_data_cti: This file describes the community temperature index per box. It contains 14 columns and 112 rows. CTI: Community temperature index [°C]