Planning long-term vegetation studies at landscape scales

Long-term ecological research is receiving more attention now than ever before. Two recent books, Long-term Studies in Ecology: Approaches and Alternatives, edited by Gene Likens (1989), and Long-term Ecological Research: An International Perspective, edited by Paul Risser (1991), prompt the question, “Why are these books so thin?” Except for data from paleoecological, retrospective studies (see below), there are exceptionally few long-term data sets in terrestrial ecology (Strayer et al. 1986; Tilman 1989; this volume). In a sample of 749 papers published in Ecology, Tilman (1989) found that only 1.7% of the studies lasted at least five field seasons. Only one chapter in each of the review books dealt specifically with expanding both the temporal and the spatial scales of ecological research (Berkowitz et al. 1989; Magnuson et al. 1991). Judging by the growing number of landscape-scale long-term studies, however, such as the Long-Term Ecological Research (LTER) Program (Callahan 1991), the U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program (EMAP; Palmer et al. 1991), the U.S. Army’s Land Condition-Trend Analysis (LCTA) Program (Diersing et al. 1992), and various agencies’ global change research programs (CEES 1993), there is a growing interest to expand ecological research both temporally and spatially.