Investigating the Soil Microbial Community Structure Under Reclaimed Roads in North Dakota.

Road construction for mineral exploration and extraction in the Little Missouri National Grasslands (LMNG) has produced thousands of miles of roads and utility corridors. Such roads are to be reclaimed to pre-construction vegetative biodiversity as described by the US Forest Service as part of the Federal Multiple Use Sustained Yield Act of 1960. Two decades after restoration, neither vegetation nor soil physical and chemical properties of the roads have returned conditions of adjacent native prairie. Previous studies have confirmed significantly lower levels of soil organic matter (SOM) on the reclaimed roads. Decreased SOM has been correlated with reduced microbial biomass, microbial species composition, and enzyme activity. Decreases of SOM may have led to differences in the microbial ecology of the sites. Microbial communities tend to be influenced by plant communities. Lack of native vegetation may be explained by differences in the soil microbial community structure. Contemporary microbial community structure will be determined using phospholipid fatty acid analysis. Other measurements include microbial biomass carbon and nitrogen to measure relative magnitude of the on- and off-road communities; enzyme activity will enumerate the nutrient cycling status of the soil population on and off the roads. Samples will be collected in close proximity to sites from preceding studies to permit inclusion of vegetation and soil physical and chemical data in the analysis. The ultimate goal of the study is to use multivariate analysis techniques to identify and rank vegetative, soil physical and chemical, and biological properties that serve as indicators of restoration success. We hope to apply these findings towards the development of improved restoration techniques for the US Forest Service.