Sand bluestem is found almost exclusively on sandy soils. It is most
common on sandhills, windblown sand dunes, and high and low sandy
plains. It is only occasionally found on moderately coarse soils [
53].
In the Northern and Central Great Plains, sand bluestem appears to be
restricted to the upper and middle elevations of sand dunes and
sandhills [
3,
5,
6,
51]. This preference is apparently related to soil
moisture. In sandhills, there is very little soil development because
of wind erosion. Here coarse-textured sands are found at the tops of
dunes, and the finer sands near the bottom. The sandy characteristic of
the soil at the upper reaches of the sand dunes allows for deep water
percolation with very little runnoff. This water is stored at depths
below 23.5 inches (60 cm) and is available to deeply rooted species such
as sand bluestem throughout the growing season, even during dry summer
periods [
4].
Sand bluestem's importance in a plant community tends to decrease as
sand content of the soil decreases. Finer textured soils do not absorb
water as efficiently, nor does the water percolate as deeply, as in
sandy soils. On these sites, sand bluestem must compete with
shallow-rooted grasses, such as Stipa, Agropyron, and Bouteloua spp.,
which are better able to extract moisture in this soil type. Barnes and
Harrison [
4] observed that sand bluestem plants growing on fine-textured
soils at the lower slopes of sand dunes experienced greater water stress
than plants growing at mid or upper slopes.
Elevational ranges for sand bluestem in several western states are as
follows [
8,
19,
25,
62]:
under 5,000 feet (1,524 m) in the Rincon Mountains, AZ
from 3,500 to 5,200 feet (1,067-1,585 m) in CO
3,000 to 7,000 feet ( 914-2,134 m) in NM
2,800 to 3,800 feet ( 853-1,158 m) in MT
4,100 to 4,800 feet (1,250-1,463 m) in WY
4,600 to 5,800 feet (1,400-1,770 m) in UT