AMY J. SYMSTAD,^* F. STUART CHAPIN,^** DIANA H. WALL,^*** KATHERINE L. GROSS,^****,***** LAURA F. HUENNEKE,^****** GARY G. MITTELBACH,^{*******,*****} DEBRA P. C. PETERS,^******** DAVID TILMAN<sup>*********


*</sup>Amy J. Symstad (asymstad@inhs.uiuc.edu) was with the Illinois Natural History Survey in Savanna, IL, when this article was prepared; she is now a research ecologist with the US Geological Survey, Mount Rushmore National Memorial, Keystone, SD 57751-0268.
^**F. Stuart Chapin III is a professor at the Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775.
^***Diana H. Wall is a professor and director of the Natural Resource Ecology Laboratory at Colorado State University, Fort Collins, CO 80523.
^****Katherine L. Gross is a professor in the Department of Plant Biology, at Michigan State University
^*****Gross and Mittelbach are based at the W. K. Kellogg Biological Station in Hickory Corners, MI 49060.
^******Laura F. Huenneke is a professor and department chair in the Department of Biology at New Mexico State University, Las Cruces, NM 88003-8001.
^*******Gary G. Mittelbach is a professor in the Department of Zoology, at Michigan State University
^********Debra P. C. Peters is a research scientist at the US Department of Agriculture, Agricultural Research Service, Jornada Experimental Range, New Mexico State University, Las Cruces, NM 88003-0003.
^*********David Tilman is director of the Cedar Creek Natural History Area and McKnight Presidential Chair in Ecology in the Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108.