As the Smithsonian observes its 150th anniversary this year, I want to reflect on how science has benefited from the Institution's longevity. Armed with the farsighted mandate of its benefactor, James Smithson, the Institution continues to add to its physical collections and its written (now computerized) records of the state of the natural world, providing scientists with a baseline for measuring changes in the environment. By monitoring changes in the world's flora and fauna, and by examining or analyzing the causes, scientists can predict more reliably how long and to what degree these changes may continue.
Long-term monitoring of specific uninhabited natural sites allows Smithsonian scientists to measure ecosystem changes wrought by hurricanes or other natural events. Scientists from the National Museum of Natural History began running lines across a coral reef in Belize in early 1972 to record the kinds and number of organisms found at a set distance on either side of the lines. The project continues and now includes the reef's adjacent lagoon. Such a study furnishes valuable information on the health of the coral reef so that it can be managed to withstand increasing tourism.
Coral reefs have also been monitored for a long time in Panama, where the Smithsonian Tropical Research Institute (STRI) operates its marine laboratory at Galeta, just east of the Caribbean entrance to the canal. The laboratory is built over a reef that was covered by an oil spill in 1968 and again in 1986. STRI's fund of data about the reef's condition, gained by monitoring it for more than 30 years, was invaluable to the Department of the Interior's Mineral Management Service when it examined how corals, sea grasses and mangroves recovered from the spill.
In 1982, at its forest reserve on Barro Colorado Island, STRI launched a major effort to study the dynamics of an unstressed tropical forest ecosystem. In cooperation with scientists from Princeton and other universities, STRI inventoried 120 acres of forest. Of 330,000 trees recorded on this plot, 21 species are represented by a single tree. Such monitoring, updated every five years, records how often a canopy tree falls and which seedling species grow to fill the canopy gap. Many seedlings survive for decades with little growth, waiting for direct sunlight to reach them. By establishing similar plots elsewhere in the tropics, Smithsonian scientists can compare the growth and composition dynamics between Old and New World tropical forests. There are 12 such plots in 11 tropical countries. By understanding the dynamics, scientists and forest managers may be able to stimulate natural regeneration of tropical forests in areas where ill-advised settlement projects have failed and where the land is returning to forest.
The monitoring programs of the Smithsonian Environmental Research Center (SERC) have added valuable new insights into our understanding of the natural flux of gases between soil, vegetation and atmosphere. This research facility has recorded the acidity of every measurable rainfall since 1970. During the 1970s, rainfall became increasingly acid. By the 1980s, however, the average annual acidity of rain appeared to stabilize, gradually improving as cleaner fuel, smokestack scrubbers and other innovations reduced power plant emissions. Improvement is slow now because the advances of the 1980s have been partially offset by rapid increases in the volume of automobile fuel being burned. The impact of changing levels of acidity is manifold for terrestrial, avian and aquatic life, and their habitats.
At SERC, scientists have monitored the watershed of Muddy Creek since 1973, continually recording water discharge, sediment load and nutrient runoff. No other watershed in the country enjoys such a detailed record of runoff--data that will help researchers predict when the fish population of the adjacent Rhode River estuary and, by extension, the upper Chesapeake Bay might disappear. The increasing use of powerful nutrients on crops and lawns in the adjacent watershed fertilizes the water flowing off the land to such an extent that algal blooms choke the waterways. The decomposition of algal mats consumes so much oxygen that there is often not enough left for fish to breathe. Finally, SERC has monitored the carbon dioxide exchange of the center's spartina grass marsh, leading to an understanding of natural variation in carbon assimilation and release of carbon dioxide into the atmosphere, knowledge that is crucial in estimating greenhouse effects.
The importance of projects such as those described is immeasurable. Experience has shown that few, if any, other institutions are equipped to conduct them. Universities have attempted to do so, but projects are subject to the tenure of the academics who implement them. Projects sponsored by federal agencies are subject to the priorities of changing political administrations. The Smithsonian, however, has been relatively free of the effects of political transitions in its research, and by the nature of its governance as a trust instrumentality, it is ideally suited to carry out essential long-range research for the ultimate benefit of all humans.