Consider the abundant information on prehistoric land cover and species distributions derived through the creative efforts of paleoecologists. Integration of coarse-resolution data such as these with information derived from original land surveys of the country (data curated by the Bureau of Land Management), and the U.S. Forest Service's data on the fire history of North America, for example, could make the characterization of historic landscape change quite tractable. When combined with more recent, remotely sensed data, from the earliest satellite deployments up to and including today's advanced technologies, it is possible to stitch together a continuous time line, from prehuman times to the present. This effort will focus, initially, on one or a few test sites, areas of modest size with relatively complete and readily accessible data. Once the idea is tested and refined, the project will expand to encompass larger areas, and eventually, much of the North American continent.
The sources of information on landscape change span the period of human habitation of North America. Much of the impact that humans have had on the environment can be viewed as a series of unplanned experiments, with particular perturbations generating measurable responses, in the form of contractions in the ranges of some species and expansions in the ranges of others. Within the context of these temporal dynamics, species extinctions and the spread of non-indigenous species may be seen as the extreme cases, where biological elements are lost or introduced. These experiments have been run and environmental scientists are beginning to assemble the data needed to assess the results. The first task is to develop a clearer understanding of the historic changes in plant and animal distributions and their relation to human-induced changes to the landscape. Given these understandings, land managers will be able to review the effects of past perturbations and apply this information in evaluating the likely outcomes of future land uses.
Your comments are invited. NBS headquarters in Washington has established an email account exclusively for the LUHNA project: luhna@ibis.mib.nbs.gov. Although no NBS staff has yet been assigned exclusively to this project, several people will be tending to the messages as time allows. Once the project is firmly established, a bulletin board format will be used to permit an open exchange of ideas among all collaborators and interested parties.
NBS will assemble a directory of interested individuals in the LUHNA project, and a bibliography of publications related to the LUHNA concept. Your contributions, submitted in the following formats, would be appreciated.
Submissions to both documents will be compiled and distributed electronically to all respondents, unless you request otherwise. If you wish to be on the mailing list but not in the directory, please indicate that on the line immediately above your name.
We look forward to your comments and our continuing interaction on this ambitious project.
Thomas D. Sisk is special assistant to the director, and Barry R. Noon is acting chief scientist, both of the National Biological Service of the U.S. Department of the Interior in Washington D.C.