Classification of the Pawnee National Grasslands

Original Scope of Classification Work - Classification of vegetation provides an inventory to assess change, a common language to compare communities with other LTERs, and a baseline for land stewardship decisions. Several initial efforts toward mapping and vegetation data collection have already been started, but not a structured community analysis and subsequent mapping. The initial phase of this project would use the thousands of previously collected plot data to develop a vegetation classification. Data will be analyzed using a variety of classification and ordination techniques to determine the most parsimonious classification system and subsequently compared to the National Vegetation Classification Standard (NVCS) at both the Alliance and Association levels. Any new Alliances or Associations will be proposed for modification of the NVCS. All plot data will be input into VEGBANK for anyone to use. The classification will be related to environmental factors on the landscape and mapped in GIS. We expect a gradient-driven distribution of vegetation that is related to a complex of environmental factors, including soil characteristics and topographic characteristics. Environmental data (soil type, aspect, slope position, disturbance history) will be related to vegetation classification groups.

Several questions linger in regard to transferring the NVCS to mapping units, including appropriate scale that often depends on the research or management question. We will map the vegetation at the Alliance, Association and Group levels to determine which is most appropriate and for what questions. Despite previous efforts, parts of the area may have been missed by previous sampling, so mapping of plots will be used to determine further sampling efforts to fill in gaps. Subsequent sampling of additional plots will be the second phase of this study, and these plots will be used to examine the efficacy of the classified Associations and Alliances and their mapped units, thus validating the classification.

Progress on Scope of Work – We have compiled various abiotic GIS data sets (see maps below) and a land-type classification. We used this classification to develop a stratified sampling of areas, based on an east-west gradient in elevation and precipitation, parent geology, and soils. Within each land type, plots are being sampled along the range of topographic position and aspects. A total of 102 plots have been collected using the Carolina Vegetation Sampling protocol. For a prelimary look at the results, see the following poster given at the IAVS conference in Estonia, 2013.


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Restoration Ecology of Short Grass Steppe

The shortgrass steppe region of northeastern Colorado has been impacted by human and naturally-caused disturbances.  Some of the disturbances impacting this region are intense such as mining and construction.  Others are more subtle such as drought, grazing and the impact of prairie dogs (Peters et al., 2008).  These more consistent disturbances have shaped the vegetation patterns observed on the shortgrass steppe. As humans continue to encroach on natural areas, it is important to understand how systems respond to this pressure and equally important to understand how citizens view these disturbances.  Without community support, conservation and stewardship activities are constrained. 

One of the goals of environmental education is to develop in students an understanding of the natural world, the impact humans have on the natural world, and the processes such as land reclamation and restoration that mitigate human impacts (Davis, 1998; Thomson &  Hoffman, 2004).  Through ecological and environmental science education utilizing experiences with nature, students gain an eco-consciousness and desire to minimally impact the natural world (Knapp, 1999).  To make a successful transition toward eco-consciousness, students must understand human impacts on the natural world and perceive the need for intervening through the process of restoration and reclamation. 

Schibout’s dissertation investigated the response of the shortgrass steppe to gravel mine reclamation and release from cattle grazing as well as high school students’ changed perceptions after visiting a gravel mine reclamation site.  Included in the dissertation is a study which investigated noxious weed interactions with native vegetation in an attempt to understand mechanistic controls of community assembly that may be used for restoration. 

Need for Restoration Evaluation of the Shortgrass Steppe
Without restoration, damage caused to the ecosystem by erosion, decreased productivity, invasion of exotic species and loss of biodiversity will have long term negative impacts (Bradshaw, 2002).  In the absence of intervention, impacted ecosystems could cause pollution and risk to human health (Ng, 2002).  Restoration will not create an ecosystem identical to the one prior to the disturbance, but it should rehabilitate the environment through reconstruction of ecological functions similar to the pre-disturbed environment (Choi, 2007). 

Great need exists to evaluate reclamation success for grasslands.  Ruiz-Jean and Aide (Ruiz-Jaen &  Aide, 2005) examined 68 restoration studies published between 1996 and 2003.  Many of these studies dealt with restoration projects of wetland or forested areas.  Only 13 of these studies examined grassland or prairie restoration, and of these 13, only four studied reclamation from mining disturbance (Cullen &  Wheater, 1993; Chapman &  Younger, 1995; Corbett et al., 1996; Bisevac &  Majer, 1999).  None of these grassland studies were conducted on the shortgrass steppe but instead were conducted in U.S. tallgrass prairie, Australian grassland, or European grassland.  The results from these reclamation studies generally showed that such efforts were effective in increasing species diversity and productivity (Bisevac &  Majer, 1999).  

Schiebout, M., & Franklin, Scott B. In Press-2014. Response of Steppe Riparian Areas to the Exclusion of Cattle Grazing: Comparison at Different Spatial and Temporal Scales. Southwestern Naturalist 59: PDF