Scolytinae/Platypodinae species species richness in 50 × 50 km grid cells across mainland USA with associated predictor variables

A list of georeferenced Scolytinae and Platypodinae occurrence records in
the USA was extracted from the Bark and Ambrosia Beetles of the Americas
Database. In addition to geographical coordinates, each record included
species, status of nativeness (native or non-native in the USA), principal
host type (either conifer or angiosperm), and feeding guild (true bark
beetles, ambrosia beetles, and “other”. The geographic coordinates of all
occurrence records of individual Scolytinae/Platypodinae species were used
to calculate species richness in 50 × 50 km grid cells (in cases of
multiple records of the same species inside one grid cell, only one record
was considered). The final data thus consisted of 3,376 cells. The dataset
also includes values of environmental and socio-economic predictor
variables: (i) average annual mean temperature [°C]; (ii) annual
precipitation total [mm]; (iii) human population density [no. inhabitants
per cell]; (iv) average income per capita ; (v) total length of roads
[km]; (vi) total forest area [km^2^]; (vii) basal area of native
angiosperms [m^2^]; (viii) basal area of non-native angiosperms [m^2^];
(ix) basal area of native conifers [m^2^]; (x) basal area of non-native
conifers [m^2^]; (xi) number of native angiosperm species; (xii) number of
non-native angiosperm species; (xiii) number of native conifer species;
(xiv) number of non-native conifer species. Basal area and species
richness (number of species) were derived from a raster database of the
live tree species basal area interpolated for each species in the
contiguous USA from forest inventory plt. Additionally, (xv) number of
traps in a grid cell.