Wooded draws or “coulees” in the western Dakotas are associated with the steeper portions of large river valleys such as the Missouri, Cheyenne, and White andtheir main tributaries. These woodlands are a mixture of green ash, hackberry, American elm, cottonwood, and Rocky Mountain juniper. All but juniper also dominate nearby riparian habitats. Shrub species usually outnumber tree species and are dominated by chokecherry, Saskatoon serviceberry, wild plum, buffalo currant, fragrant sumac, and western snowberry. The naturally occurring wooded draws of western South Dakota were decimated during homesteading. The combination of heavy woodcutting, severe overgrazing, cultivation of steep land, and the 1930s drought left a deforested, eroded, and ecologically impoverished landscape. Consolidation of the many failed small farms into large ranches initiated the healing process. For example, a 10,000-acre parcel of land farmed by 37 families in 1890 was consolidated into one ranch (the Mortenson Ranch) by the 1950s (Fig. 1). Cultivation ceased except on flat tablelands, grazing intensity was reduced, and trees began to reappear in the draws. The ranch’s riparian forest along the lower Cheyenne River was permanently flooded and destroyed by Oahe Reservoir (Missouri River) in the 1960s. The loss of this forest for overwintering cattle and sheltering of spring calves redirected attention to the restoration of wooded draws as replacement protective habitat. An expansion of trees and shrubs followed management changes, which included cross-fencing, adoption of a rest–rotation grazing system, and rapid movement of cattle through about 20 pastures averaging 500 acres each. Riparian areas and wooded draws have been utilized primarily as wintering and calving areas during the nongrowing season. Permanent photo points and vegetation transects at the Mortenson Ranch were established in the early 1990s and revisited in 2000 to assess the vigor and rate of spread of vegetation in wooded draws. This paper reports those findings.
Recovery of wooded draws at the Mortenson Ranch occurred in 2 phases: 1st with land consolidation and halting of most woodcutting and farming beginning in the 1930s, followed by cessation of season-long summer grazing in wooded draws beginning in the 1970s. In the second phase: cross-fencing, adoption of a rest–rotation grazing system, and rapid movement of cattle through about 20 pastures averaging 500 acres each. Riparian areas and wooded draws have been utilized primarily as wintering and calving areas during the nongrowing season.
|Climate change impacts||Effect of Nbs on CCI||Effect measures|
|Biomass cover loss||Positive||Tree basal area, tree density, sapling density, shrub cover, span of woodland (woodland expansion outside restored plots)|
The Mortenson Ranch is located in Stanley County, South Dakota, near the confluence of the Cheyenne and Missouri rivers. The long and deep, east–west running Todd’s Draw transects the property.