Tree density and the 48 explanatory variables of the 4367 plots in North American boreal forests.

Location: North American boreal forests

Size: 4367 plots

Type: ABMI, NFI, PSP plots

Prov: province, territory or state where the plot is

Obs_Density: tree density from field measurement (trees/ha; DBH >= 10.0 cm).

Est_Crowther_Density: tree density estimates from Crowther et al.'s biome map (trees/ha).

HumanDev: percent of developed and managed land

HumanPop: population density (km^-2)

Landcover: land cover type defined in the Land Cover Classification System (LCCS)

Long: longitude (° W)

Lat: latitude (° N)

Elev: elevation (m)

Slope: angle of inclination of the terrain (°)

Eastness: sine of aspect of the terrain to north

Northness: cosine of aspect of the terrain to north

TRI: terrain ruggedness index

Standht: stand height as mean height of the tallest 3 trees (m)

Standht2: square of Standht (m²)

Canopyht: canopy height from Sentinel-2 imagery (m)

LAI: leaf area index

EVI: enhanced vegetation index

NDVI: normalized difference vegetation index

ASM_EVI: angular second moment (orderliness) of EVI

Homogeneity_EVI: similarity of EVI between adjacent pixels

Contrast_EVI: exponentially weighted difference in EVI between adjacent pixels

Dissimilarity_EVI: difference in EVI between adjacent pixels

TCECC: cation exchange capacity of the clay fraction in the topsoil (soil between 0 and 30 cm under the ground) (cmol kg^-1)

TpHH2O: topsoil pH (in water)

TC: topsoil carbon content (kg C m^-2)

AET: actual evapotranspiration as water use (mm day^-1)

Alpha: Priestley-Taylor alpha coefficient for soil water deficit

nhx: anthropogenic NHx input (g N m^-2 year^-1)

noy: anthropogenic NOy input (g N m^-2 year^-1)

Evapotranspiration: Penman-Monteith reference evapotranspiration (mm day^-1)

Aridity: ration between mean annual precipitation and mean annual Penman-Monteith reference evapotranspiration

Solar_Radiation: incident solar radiation (kJ m^-2 day^-1)

Wind: wind speed at 2 m above the ground (m s^-1)