Species analysis
Statistical exploration
Classification trees
Variables
Horned Lark
Occurred the most disproportionately in hexagons with annual
precipitation of 218-303 mm and April minimum temperature (hex.
avg.) of -5.68 to 3.53� C. In slightly moister regions (303-506 mm
annual precipitation), it occurred mainly among hexagons with less
than 6% mixed conifer forest (Northeast Oregon) and whose most
extensive land cover type occupies more than 22% of the hexagon. In
yet moister regions (506-681 mm annual precipitation), it occurred
mostly in hexagons with more than 2% sagebrush steppe.
Paradoxically, in the wettest parts of its Oregon range (more than 681
mm annual precipitation), its occurrence is associated most closely
with hexagons having relatively large areas of streamside forest,
wetlands and wet shrubland, and freshwater marsh. The logistic
regression analysis showed positive or negative association with big
sagebrush shrubland, sagebrush steppe, number of land cover types,
the extent of public land, April precipitation (hex. avg.), and-to a
lesser degree-June minimum temperature (hex. max.) and June
minimum temperature (hex. min.).
Classification trees
Hexagons: using ONHP land cover classification (accuracy score: 91.82)
Squares: using ONHP land cover classification (accuracy score: 88.51)
Hexagons: using AVHRR land cover classification (accuracy score: 86.68)
