Caroline Bledsoe
Snow flurries and windy weather in Northern Wisconsin didn’t dampen the enthusiasm of those of us attending the “Variability in North American Ecosystems” workshop on April 18-22 at the Trout Lake Station, Wisconsin. I joined representatives from 12 LTER sites for 4 days of working on computers, exploring an intersite LTER data base (code name “VANIE”), and developing intersite hypotheses, which were tested at the workshop. John Magnuson and the group from North Temperate Lakes LTER did a superb job of planning, organizing, and setting up the workshop.
The LTER representatives were:
- Art McKee, AND (Andrews)
- Peter Bayley, ILN (Illinois Rivers)
- John Yarie, BNZ (Bonanza Creek)
- Gary Cunningham, JRN (Jornada)
- Richard Inoye, CDR (Cedar Creek)
- Don Kaufman, KNZ (Konza)
- Jon Hanson, CPR (Central Plains)
- Jim Halfpenny, NWT (Niwot Ridge)
- Cory Berish, CWT (Coweeta)
- Liz Blood, NIN (North Inlet)
- Randy Dahigren, HBR (Hubbard Brook)
- John Magnuson and Tim Kratz, NLK (North Temperate Lakes), and the gang from North Temperate Lakes
The purpose of the workshop was to analyze variability in North American ecosystems, using data on spatial and temporal variability from LTER sites. The requirements were that the data represent at least 5 years of collection from at least 5 locations at the LTER site. Subsequent statistical analyses, done by Tim Kratz from NLK, produced variances attributed to “year,” “location,” and “other” (a combination of error and interaction terms).
The workshop was well organized, with 8-10 microcomputers (Mac’s and IBM’s) and 4-5 knowledgeable computer users available to assist workshop attendees. The success of the workshop clearly reflected thorough preworkshop preparation, including visits by Magnuson to 10-12 LTER sites in the fall of 1987 and the extensive preworkshop data manipulations/statistical analyses done by Kratz. With this preparation and the excellent facilities, the workshop group was able to generate hypotheses, divide into smaller groups, and begin analyzing the data base--we were using the summary data base within about 5 hours after the workshop began!
Data were analyzed in a number of ways. Some workshop persons lumped data, whereas others split data, each with the intent of testing hypotheses about variance. Examples of hypotheses investigated were: Do ecosystems differ in variability? What is the importance of landscape position? Does variability pass up the food web? Are early successional stages more variable than late successional stages? Are predators less variable than their prey? How does variability change with degree of aggregation of functional groups?
It is too early to list conclusions and major hypotheses from the workshop. Several manuscripts were outlined and individuals were identified to complete them. If possible, the workshop attendees will meet a second time in the fall of 1988 for further discussion and review of these manuscripts.
In summary, the workshop was very successful, resulting in a LTER Intersite Data Base, as well as the beginnings of intersite comparisons on a multitude of scales. Although additional work is required to complete what was begun at the workshop, I believe we are beginning to generate payoffs from the LTER Network.