Long-Term Ecological Research (L TER) is a pilot program supported by the National Science Foundation's Division of Biotic Systems and Resources (BSR). The program was developed from 1976 to 1979 when the first open competition for support was announced. L TER acknowledges:
1.That there are ecological phenomena that occur on time scales of decades or cen­
turies; periods of time not normally investigated with research support from NSF.
2. That many ecological experiments are performed without sufficient knowledge of the year-to-year variability in the system. Interpretation is, therefore, difficult. This is especially true when the system in which the experiment is performed is not at equilibrium.
3.That long-term trends in natural ecosystems were not being systematically monitored. Unidirectional changes that were observed could not be distinguished from cyclic changes on long time scales.
4.That a coordinated network of sites was not available to facilitate comparative experiments. Furthermore, data management was not being coordinated between research sites. Therefore, comparative analyses could not be performed and theoretical constructs could not be conveniently tested.
5. That examples of natural ecosystems were being converted to uses incompatible with ecological research.
6.That advances in ecological research have often treated phenomena at higher or lower levels of organization as insignificant or constant or by oversimplification. This problem can be alleviated by performing intensive investigations at single sites, leading to an accumulation of overlapping information. Through time, site specific research will generate increasingly valuable data sets, revealing pattern and control at several levels of ecosystem organization.
Initial convergence of the L TER effort was encouraged by requiring that sites ad­dress research efforts in five core areas. These were (1) pattern and control of primary production; (2) spatial and temporal distribution of populations selected to represent trophic structure; (3) pattern and control of organic matter accumulation in surface layers and sediments; (4) pattern of inorganic inputs and movements of nutrients through soils, groundwater, and surface waters; and (5) pattern and frequency of disturbance to the research site.
The institutions serving in support of L TER sites are committed to encourage col­laborative research by scientists at other institutions. L TER sites should be considered regional or national research facilities. If you are interested in using these facilities, please contact directly the sites identified in this brochure.