Impact of cultivation legacies on rehabilitation seedings and native species re-establishment in Great Basin desert shrublands

Authors: MORRIS, LESLEY - Utah State University; Monaco, Thomas; Sheley, Roger

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2013
Publication Date: 5/1/2014
Citation: Morris, L.R., Monaco, T.A., Sheley, R.L. 2014. Impact of cultivation legacies on rehabilitation seedings and native species re-establishment in Great Basin desert shrublands. Rangeland Ecology and Management. 67:285-291.

Interpretive Summary: Little in known about how cultivation legacies affect the outcome of rehabilitation seedings in the Great Basin, even though both frequently co-occur on the same lands. We examined these cultivation legacies by comparing the density of seeded Agropyron cristatum (crested wheatgrass), vegetation composition, and ground cover within areas historically cultivated and seeded to adjacent areas that were seeded but never cultivated. Historically cultivated areas had lower crested wheatgrass density at half of the sites (p<0.05) while the native shrub Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) simultaneously experienced reductions (p<0.05). Compared to seeded only areas, density of crested wheatgrass was most reduced in the historically cultivated areas of an alkali site where cover of exotic forbs, especially Halogeton glomeratus (halogeton) increased (p<0.05), as did the native shrub Sarcobatus vermiculatus (black greasewood) (p<0.05). Regardless of cultivation history, the most recently seeded site had the lowest crested wheatgrass density and was dominated by the invasive annual Bromus tectorum (cheatgrass). In contrast, a site seeded more than 35 years ago had higher density of crested wheatgrass (p<0.05) and three-fold lower density of the native Poa secunda (Sandberg bluegrass) in historically cultivated areas relative to those seeded only. Bare ground cover varied two-fold across sites but was greater in historically cultivated areas at three sites (p<0.05). These results suggest that cultivation legacies can reduce seeding success and re-establishment of native vegetation and should be considered prior to restoration research or implementing management.

Technical Abstract: Little is known about how cultivation legacies affect the outcome of rehabilitation seedings in the Great Basin, even though both frequently co-occur on the same lands. We examined these cultivation legacies by comparing the density of seeded Agropyron cristatum (crested wheatgrass), vegetation composition, and ground cover within areas historically cultivated and seeded to adjacent areas that were seeded but never culitvated. Historically cultivated areas had lower crested wheatgrass density at half of the sites (p<0.05) while the native shrub Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) simultaneously experienced reductions (p<0.05). Compared to seeded only areas, density of crested wheatgrass was most reduced in the historically culitvated areas of an alkali site where cover of exotic forbs, especially Halogeton glomeratus (halogeton) increased (p<0.05), as did the native shrub Sarcobatus vermiculatus (black greasewood) (p<0.05). Regardless of cultivation history, the most recently seeded site had the lowest crested wheatgrass density and was dominated by the invasive annual Bromus tectorum (cheatgrass). In contrast, a site seeded more than 35 years ago had higher density of crested wheatgrass (p<0.05) and three-fold lower density of the native Poa secunda (Sandberg bluegrass) in historically cultivated areas relative to those seeded only. Bare ground cover varied two-fold across sites but was greater in historically culitvated areas at three sites (p<0.05). These results suggest that cultivation legacies can reduce seeding success and re-establishment of native vegetation and should be considered prior to restoration research or implementing management.