Ecological Research, Long-Term

Many ecological studies last just one or a few years. There are many rea­sons for this. Sometimes people are doing the study as part of their research in graduate school and they want a project they can finish in a few years. Much ecological research is funded by various federal and state agencies, and these grants are normally for only one to three years. The problem with this approach is many important ecological processes occur over longer time frames than this. For example, droughts and fires play a very important role in determining what trees can grow in certain environments, such as savannas. If one studied a savanna for three years, and no drought or fire occurred during this time, one would never discover the importance of fire and drought in that habitat. Some animals such as snow shoe hares and ruffed grouse experience dramatic fluctuations in the size of their popula­tions. If one conducted a study of just a few years on these species, one would never learn the fascinating fact that these populations experience reg­ular population cycles approximately ten years in length.

Thus, although much important ecological information can be learned from short-term studies, long-term studies are essential to understanding many processes that occur over a longer period of time. Fortunately, orga­nizations like the National Science Foundation (NSF), a federal agency that funds much ecological research, have recognized the need to support some long-term ecological studies. In 1980, the NSF instituted a special funding program called the Long Term Ecological Research (LTER) program. In­stead of funding projects for just one to three years, this program funds re­search for at least five years and usually for much longer. Some projects have been funded for as long as twenty years, and funding is expected to continue for these projects into the future. More than twenty LTER research sites are located throughout North America in almost all the major habitats, in­cluding prairies, forests, deserts, mountains, tundra, freshwater lakes, and ocean coastal environments. This funding has enabled scientists to study such important issues as the long-term effects of acid rain on forests and aquatic organisms, the long-term effects of pollution on native prairie plants, and the possible impacts of rising atmospheric carbon dioxide levels on for­est growth.

Ecologists are particularly interested in the possible ecological effects of global warming. Since this is a process that occurs over decades, and even centuries, very long studies are needed. Some of these studies are now un­derway and are expected to continue for decades. In other cases, ecologists have made use of data collected in the past to answer certain questions involving global warming. For example, century-old scientific notes and journals containing the spring arrival dates of migrating birds and bloom­ing dates of wildflowers have shown that spring is occurring about ten days earlier in Europe and North America than it was 150 years ago. Some churches in Europe have recorded the dates of ice-out in nearby lakes for several hundred years. These continuous monitoring efforts represent some of the longest ecological data sets in existence.

References

Bowman, W. D., and T. R. Seastedt. Structure and Function of an Alpine Ecosystem. Oxford: Oxford University Press, 2001.

Knapp, A. K., J. M. Briggs, D. C. Hartnett, and S. L. Collins. Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie. Oxford: Oxford University Press, 1998.