Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.

Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Successional dynamics of a Nebraska Sandhills blowout*

Charles Howard Butterfield, University of Nebraska - Lincoln


Plant communities are highly diverse and dynamic systems, both spatially and temporally, that often depend on differing forms of disturbance to maintain diversity. Understanding the successional dynamics of a system is fundamental to our understanding of ecosystems and their management. The objective of this descriptive 15-year study, conducted at the Nature Conservancy Niobrara Valley Preserve near Johnstown, Nebraska, was to quantify and interpret patterns of seral change occurring in a Sandhills blowout [Valentine Association (mixed mesic Typic Ustipamments)] by defining consistent patterns of plant community change. Grazing was excluded from two active blowouts (12 ha and 5 ha) in 1981 and 1990, respectively. Each study area was overlain with a permanent grid system to facilitate mapping of the vegetation and sand erosion/deposition annually through 1995. Sand erosion/deposition patterns and plant community data were digitized into a Geographic Information System (GIS) to produce community maps. Spatial data for patches, class and landscape-level plant communities were rasterized, and analyzed for multiple spatial statistics by FRAGSTATS. The shape index was superior to a two-dimensional fractal analysis in characterizing patch and class dynamics. Four successional trajectories within a Nebraska Sandhills blowout were evident: (1) seral advancement of minimally disturbed perennial grass patches, (2) edge closure, (3) bare sand to blowoutgrass to blowoutgrass/sand muhly to perennial grass/sand muhly to perennial grass, and (4) bare sand to annuals to annual/perennial mixture to perennial grass. Areas of minimal disturbance had attained a high seral stage in at least 10 years. Within 8 years, there were minimal levels of vegetation established on the most disturbed sites. However, these areas may require in excess of 15 years of grazing exclusion to attain a high seral stage. Research on the causal mechanisms of these different successional trajectories is needed to enhance our management of blowouts. ^ *Follows the style and format of Ecological Monographs.^

Subject Area

Biology, Ecology|Agriculture, Range Management

Recommended Citation

Butterfield, Charles Howard, "Successional dynamics of a Nebraska Sandhills blowout*" (2002). ETD collection for University of Nebraska - Lincoln. AAI3038973.