Evaluation of Topsoil Depth Effects on Various Plant Parameters Within a Reclaimed Area in Northeastern Wyoming

Abstract

A project was initiated in 1998 to investigate the effect of varying topsoil depths on soil parameters, plant cover, production and diversity on a coal mine in northeastern Wyoming. Soil and vegetation information was collected for three consecutive growing seasons (2000 through 2002) on reclaimed areas with three topsoil treatment depths (15, 30 and 56 cm) and from two native reference areas (Upland Grass and Breaks Grass) at the mine. For the vegetation analysis, total vegetation cover, total cover, average number of species and total number of species were the primary parameters. Vegetation production was measured in 2002 only. Analyzed soil parameters included pH, electrical conductivity and sodium adsorption ratio at 15 cm intervals throughout the treatment depth and the immediate underlying spoil material. Although three years of data has been collected for this project, the primary emphasis of this paper will be 2002. No significant differences in vegetation and soils were noted by treatment in the 2000 through 2002 data. Location effects, however, were numerous, which emphasizes the difficulty in utilizing native reference areas as standards for reclamation success on reclaimed areas. All vegetative parameters were generally higher in reference areas with the exception of production. Diversity indices on the reclaimed and reference areas were also evaluated. The Shannon-Wiener indices were significantly different by location throughout 2000 to 2002 and by treatment in 2001, i.e., the 30 cm treatment was significantly higher in diversity than the 56 cm treatment. Previous research has indicated diversity differences in topsoil depth treatment levels increase over time. For this project, differences in topsoil depth treatments will likely increase over time and/or with more typical precipitation patterns.

The Effects of Soil Depth and Other Soil Characteristics on Plant Community Development in North Dakota

“…This grass is a non-native, aggressive cool season grass with higher productivity than more diverse plant communities. As seen in other studies, when non-seeded species invade a site and increase diversity, production values decrease (Bowen, 2003;Schladweiler et al, 2003). Productivity was also significantly higher (F<0.01) in 1978 compared to 2003 for Russian wildrye plots.…”

The Effects of Soil Depth and Other Soil Characteristics on Plant Community Development in North Dakota

“…There were a variety of native and introduced species established on the ZSW which may be a result of invasion by surrounding vegetation or seed distribution through cattle grazing. Again, most of the diversity was found in reduced depths of replaced soil because these areas more conducive to higher diversity and lower production (Bowen, 2003;Schladweiler et al, 2003). In the previous study by Merrill et al (1998), rabbits also fed on alfalfa stands and caused a weak establishment.…”