|Devils Tower -- a puzzling igneous intrusion in northeast Wyoming.|
|Replacement needed, in full color (from Knight 1994).|
At Devils Tower National Monument, ponderosa pine forest is best developed on sandstone ridges, and on buried talus around the base of the Tower. With deeper roots, pines can tap into accumulated water among buried rocks or in fractures.
|Grassland - pine forest mosaics are common in the northwest Black Hills.|
Shallow-rooted grasses do well on fine soils that hold water close to the surface, for example soils derived from Permo-Triassic Spearfish red beds and shaley members of the Jurassic Sundance Formation.
What a nice orderly arrangement -- grasslands on fine soils, pines on buried talus and sandstone ridges. Our pattern-seeking minds love such things!
|From ArcGIS online; click on photo for details.|
The Black Hills were named for the ponderosa pine forests that make them appear dark against the surrounding plains (below, from Google Earth). Elevations are lower than in other mountain ranges in the region, and the relatively fast-growing ponderosas are the basis for a timber industry that costs tax-payers little or nothing (usually we subsidize timber harvest on public lands in our region).
But the Black Hills are not entirely forested. Mixed-grass prairies are common. These are indeed mixes -- of tall-grass prairie and short-grass prairie species.
From Regional Trends of Biological Resources (USGS); mixed-grass prairie zone in purple.
The photo above currently is the front-runner for Dennis’s book. The grassland on Joyner Ridge is an excellent example of mixed-grass prairie, with the following grasses common:
tall-grass species: big bluestem, green needlegrass, needle-and-thread
short-grass species: blue grama, buffalo grassI especially like this shot because of the yellow coneflowers (Ratibida columnifera) in the foreground -- they’re classic prairie wildflowers. But it will be Yale University Press that decides if the photo is appropriate.
|Hiking trails at Devils Tower (NPS); click on photo to enlarge.|
|Needle-and-thread grass on Joyner Ridge.|
Dog Town -- a highly-managed landscape.
|Two of the managers.|