As environmental disturbance, fragmentation, and pollution become more widespread, it is imperative that new collaborative mutidisciplinary research provide insights into complex ecological phenomena on a larger scale than has been possible in the past. The facility that is the subject of this project is a regional center for research on the responses of lake systems to disturbance at varying scales. The investigators associated with this facility have many years of experience using small experimental surrogate ecosystems(e.g.. experimental ponds) to identify the responses to disturbance of larger, "real world", systems. The objective of this project is to enhance the aquatic research facility at the University of Kansas field station, the Kansas Ecological Reserves (KER), in order to continue the extension of this work to larger scales. The aquatic facilities at the KER are extensive with nearly 200 experimental ponds over 55 outdoor fiberglass tanks and different types of enclosures for smaller scale experiments within these systems. Research over the 20 year history of this aquatic program, reported in nearly 100 publications, has often focused on the use of these relatively small surrogate ecosystems for aquatic research. This work has firmly established that experimental perturbations applied to these surrogate adequately simulate a variety of environmental changes. New modeling techniques are being developed to extrapolate these results to the "real world at larger spatial and temporal scales. To extend this empirical research to larger lentic ecosystems )lakes and reservoirs). 1991 a 4.5 ha, 13 m deep reservoir was constructed in a protected 50 ha watershed. This reservoir was constructed as a model ecosystem with many of the important characteristics of larger lentic systems. Now investigators working at KER can conduct empirical investigations in a large, secure and carefully managed lake/ reservoir surrogate. The proximity of this lar ger scale surrogate ecosystem to one of the largest experimental pond facilities in the nation makes the facility attractive to researchers from institutions throughout the region. No limnological manpipulations are conducted in the reservoir at the whole-lake scale so that natural reference conditions can be continually provided. However, experimental perturbations simulating environmental change at this reservoir scale can be studied in situ enclosures and in adjacent smaller experimental ponds and tanks.
