Scope 47- Long-term Ecological Research, An International Perspective

1.1 INTRODUCTION

Long-term ecological studies have been focused around the relatively straightforward notion that certain processes, such as succession, the natural frequency distributions of climate regimes, or disturbances exemplified by treefalls and fires, are long-term processes and must be studied as such (Likens, 1983; Lawes Agricultural Trust, 1984; Wiens, 1984; Coull, 1985; Greenland, 1986; Munn 1986; Strayer, 1986; Strayer et al., 1986; Peterken and Jones, 1987). Indeed, there are numerous examples in the literature in which data trends from short-term interpretations yield significantly different information from longer-term analyses. The belief has been that the collection of data over long periods of time is necessary to permit generalizations and theory over sufficiently large spatial and temporal scales to evaluate the ecological consequences of such events as fire, grazing, deforestation, acid deposition, and changes in trace gas fluxes (Callahan, 1984).

Analyses of existing long-term ecological studies show several conditions under which these types of studies are particularly beneficial. That is, long-term studies are useful when the phenomena are themselves long term in their dynamics; when the phenomena are episodic, rare, complex or subtle, and long-term measurements are needed to isolate their dynamics and the control processes; when the phenomena are poorly understood and cannot be predicted from short time scales; and when long term records are needed for making policy decisions. Despite the documented need for long-term studies, there are relatively few institutionalized comprehensive long term investigations. Those that do exist include the agricultural plots at Rothamsted in the UK, forest productivity research in Sweden, and watershed studies at Coweeta and the Hubbard Brook experimental forests in the United States. In addition these relatively large studies, there are numerous examples of individual scientists who have collected data on a phenomenon or site over long periods of time. In many instances, successful long-term studies have depended upon such individual scientists, who have been dedicated in their pursuit of measurements, over many years.

The relative paucity of long-term ecological studies is the result of several obstacles. Among the most important impediments are the following:

1. Long-term measurements may not be considered at the forefront of innovative science, and thus obtaining continuous funding is difficult.

2. The site where the measurements are made may be changed, making the long-term results meaningless or difficult to interpret.

3. The experimental design may be too ambiguous for long-term consistent measurements or may not include adequate auxiliary studies for  unravelling controlling processes.

4. The resources or incentives for the dedicated individual scientists or research leaders to continue the measurements may be inadequate.

5. Evolution in instrumentation may render the current methodology obsolete, and there may be insufficient attention to calibrating the old and new technologies.

6. New scientific advances may make the original question or hypothesis uninteresting or may provide a definitive answer; in either case, the  measurements need not be continued.

This book summarizes the results of a project that has analyzed long-term ecological research in an international context. Conducted under the auspices of the Scientific Committee on Problems of the Environment (SCOPE), the project consisted of two workshops. The first was held 18-22 September 1988, in Berchtesgaden, Federal Republic of Germany (see Table 1.1 for the list of participants). This workshop had three objectives:

1. To provide a forum for describing and analyzing selected existing long-term ecological research sites and networks from various countries;
2. To further refine the rationale for long-term ecological research and identify important existing and emerging scientific questions which could most appropriately be addressed at these sites, particularly those that relate to environmental changes at the global scale; and
3. To begin to formulate a plan for international communication and co-ordination among long-term ecological research sites.

This workshop primarily considered national or regional programs rather than long-term ecological projects of individual investigators. Designated and protected research sites offer several potential advantages, e.g. economy in site dedication and protection, sharing of equipment and data sets, and the synergism brought about by interactions among scientists, especially those from different disciplines. Nevertheless, many of the conclusions of the workshop are equally applicable to long-term studies conducted by individual scientists.

The following twelve chapters describe and discuss long-term studies from several countries: Australia, Canada, England, Federal Republic of Germany, France, Kenya, Scotland, and the United States. There are also discussions of general topics, such as administrative structure, role of sites, conceptual design, field measurement techniques, and modeling in the context of long-term ecological research. These chapters satisfy the first workshop objectives, namely analyzing existing studies on an international basis and refining the role and value of long-term ecological study. In addition, the workshop compared the international research effort with the Long-term Ecological Research Program supported by the National Science Foundation in the United States. This program involves 17 research sites and has been in existence for approximately ten years. The objectives of this program are (Callahan, 1984):

1. Long-term analysis of site-specific ecological phenomena;
2. Comparison of observations across diverse ecosystems and in terms of general ecological systems theory; and
3. Provision of large, secure, ecologically diverse sites with well-developed support capabilities.

Table 1.1 Participants in an International Workshop, 'Long-term Ecological Research: A Global Perspective', 18-22 September 1988, Berchtesgaden, Federal Republic of Germany

Many of these sites have supported long-term research for decades, and as such, represent a valuable experiential data base for further developing the concepts and processes for long-term studies.

The second workshop specifically addressed the third of the original objectives, that is, to begin to formulate a plan for international communication and co-ordination among long-term ecological research sites. Participants (see Table 1.2) were selected to represent active research programs in three biomes: arid to semi-arid, tundra-boreal, and temperate forest. During the workshop, specific plans were developed for international collaborative long-term ecological research, and working groups were identified for conducting experiments. The questions to be addressed and the proposed investigative approaches are summarized in Chapter 14.

International collaborative long-term ecological research requires not only the site-specific characteristics discussed above, but also extensive communication among the investigators. Therefore, at the second workshop, considerable attention was devoted to discussion of the newest electronic technologies for data management and communication. During the workshop, two sessions were held in a studio and the discussions were sent via satellite to more than 100 scientists at several sites across the United States. These scientists at remote sites sent questions and comments that were then discussed by the workshop in a second televised session.

Table 1.2 Participants in an International Workshop, 'Long-Term Ecological Research: International Workshop II', 2-4 October 1989, Albuquerque, New Mexico, USA

These two SCOPE workshops brought together scientists from 15 countries to analyze the approaches most likely to facilitate long-term ecological research. The following chapters describe existing international long-term research efforts, evaluate facilitating mechanisms, propose important research questions that require international co-operation, and discuss technologies that will assist in this collaboration.

1.2 ACKNOWLEDGMENTS

Funding for this project was provided by the US National Science Foundation and is gratefully acknowledged. Also, the National Committee of the Man and the Biosphere Program, Federal Republic of Germany, provided partial support for the first workshop.

1.3 REFERENCES

Callahan, J. T. (1984). long-term ecological research. BioScience, 34, 363-367.

Coull, B.C. (1985). The use of long-term biological data to generate testable hypotheses. Estuaries, 8, 84-92.

Greenland, D. (1986). Standardized meteorological measurements for long-term ecological research sites. Bulletin of the Ecological Society of America, 67, 275-277.

Lawes Agricultural Trust (1984). Rothamsted: the classical experiments. Rothamsted Agricultural Experiment Station, Harpenden, England.

Likens, G.E. (1983). A priority for ecological research. Bulletin of the Ecological Society of America, 64, 234-243.

Munn, R.E. (1986). Environmental prospects for the 21st century: implications for long-term policy and research strategies. Symposium on New Directions in International Research, Education and Practice. Ohio State University, 5-6 December 1986. Columbus, Ohio.

Peterken, G.F. and Jones, E.W. (1987). Forty years of change in Lady Park Wood: the old-growth stands. Journal of Ecology, 75, 477-512.

Strayer, D. (1986). An essay on long-term ecological studies. Bulletin of the Ecological Society of America, 67, 271-274.

Strayer, D., Glitzenstein, J.S., Jones, C.G., Kolasoi, J., Likens, G.E., McDonnell, M.J., Parker, G.G. and Pickett, S.T.A. (1986). Long-term ecological studies: an illustrated account of their design, operation, and importance to ecology. Occasional Publication of the Institute of Ecosystem Studies, No.2. Millbrook, New York.

Wiens, J.A. (1984). The place of long-term studies in ornithology. Auk, 101, 202-203.