Dendrochronology of Great Plains Tree Species - Mentor: W. Lauenroth 
During the summer of 1996 one of the SGS LTER REU students initiated a study of the dendrochronological record of ponderosa pines, limber pines, and junipers in the escarpments along the Wyoming-Colorado border.  During this first field season she collected samples and began the search for older trees which would give a lengthier record.  In the summer of 1997 a different REU student picked up this project and found two 500 year old ponderosa pine individuals which were sampled.  Her continuation of the initial work has resulted in the development of a fairly solid dendrochronology back to the 1400's.  This project is of great ecological significance since very few studies of this type have been completed on trees of the Great Plains. 

Effects of Burning on Shortgrass Steppe Plant Communities - Mentor: D. Milchunas                                     During the summer of 1997 an REU participant established an experiment to gain a better understanding of the ecological role of fire in the shortgrass steppe.  He approached this issue from spatial patterning perspective in an attempt to understand the pattern-process relationship of shortgrass steppe plant communities.  Since very little fire ecology work has been completed on the shortgrass steppe, this was an important contribution to our understanding of the system.  In addition, the Pawnee National Grasslands, who was responsible for operating the prescribed burn, did not have the personnel to carry out such an experiment, so this was an excellent way to complement their work. 

Effects of Prairie Dog and Pocket Gopher Disturbance on Soil Dynamics – Mentor: P. Stapp and P. Buckwalter 
Since there is a significant lack of information regarding effects of pocket gophers on soil dynamics, one of our 1998 REU Participants initiated a study comparing the effects of prairie dogs to those of pocket gophers.  It is hypothesized that the disturbance and mixing of soils influences the nitrogen composition and may alter species composition.  Preliminary results 

The Effects of Prairie dogs on Avian Species – Mentor: P. Stapp 
During the summer of 1998 an REU participant designed and executed an experiment aimed at better understanding the complex dynamics between prairie dogs and avian species of the shortgrass steppe.  Both activity and productivity were studied using a variable circular plot method and the use of artificial nests. Preliminary results 

Species Composition, Water and Nitrogen Concentrations in Riparian Areas of the Shortgrass Steppe – Mentors: I. Burke and W.Lauenroth 
The overall objective of this 1998 project is to characterize gradients of water availability, soil nitrogen concentration, and species composition along transects extending outward from riparian areas.  It is hypothesized that a higher proportion of exotic species will be found in areas where more resources, such as space, water, or nitrogen are available. Preliminary results 

Exotic Plant Species in Grazed and Ungrazed Areas of the Shortgrass Steppe -- Mentors: W. Lauenroth and P. Lowe
During the summer of 2000, Alissa Loeffler examined the effect of grazing on exotic species invasion, expecting to find further support for the notion that grazing decreases invasibility of non-native species on the shortgrass steppe.  Preliminary Results