Table 1 Landscape variables. A summary of all variables by category rescaled to 1 km2 and used in the prediction of wolverine genetic connectivity. Because of correlation among variables in the same categories (r > 0.3), composite climate and human disturbance variables were also created using the indicated variables in a Principal Components Analysis (PCA). The Hypothesis column indicates whether an increase in a given variable is expected to result in an increase (+) or a decrease (-) in genetic connectivity. TPI = Topographic Position Index; TRI = Topographic Ruggedness Index; HF = Human footprint; Dstrb = Disturbance Category; Topo = Topography Category; For = Forest Category.
From: Genetic connectivity of wolverines in western North America
Variable | Category | Source | Climate PCA | HF PCA | Hypo-thesis | Description |
|---|---|---|---|---|---|---|
Snow Days | Climate | NDVI1 | ● | + | Number of days with snow cover from NDVI NoData values (Fig. S5) | |
SWE | Climate | CHELSA2 | ● | + | 30-year average (1981–2010) of snow-water equivalent with permanent water bodies removed | |
Temp | Climate | CHELSA2 | ● | - | 30-year average (1981–2010) of annual maximum temperature | |
Building density | Dstrb | Micro-soft3 | ● | - | From all buildings in North America with point density tool in ARCGIS | |
Human footprint 1 | Dstrb | NASA | ● | - | 8 anthropogenic variables: built-up environment, population density, electric power infrastructure, crop lands, pasture lands, roads, railways, navigable waterways | |
SEDAC4 | ||||||
Human footprint 2 | Dstrb | Earth Systems Science Data5 | ● | - | 14 anthropogenic variables: urban, crop land, grazing, mining, energy production (oil and gas, renewable), roads, railways, power lines, electrical infrastructure, logging, human intrusion, reservoirs, air pollution | |
HWY All | Dstrb | Street | ● | - | Major Canadian and US Highways | |
Maps6 | ||||||
HWY 1 | Dstrb | Street | - | North or south of Trans-Canada Highway 1 | ||
Maps6 | ||||||
Lights | Dstrb | NASA7 | ● | - | Nighttime lights | |
DEM | Topo | USGS8 | + | 30-m digital elevation model | ||
TPI | Topo | USGS8 | + | Topographic position index: From DEM using R terrain() in ‘raster’ | ||
TRI | Topo | USGS8 | + | Terrain ruggedness index: From DEM using R terrain() in ‘raster’ | ||
Forest cover | For | NALCMS9 | + | Proportion of cells in window of conifer or mixed forest type, 30-m | ||
Forest edge | For | NALCMS9 | + | Proportion of 30-m cells in window where conifer/mixed forest was adjacent to non-forested habitat |
