Illinois Natural History Survey - University of Illinois

Collections: The Foundation of Our Research and Education Programs

From its origins in 1858 to today, the Illinois Natural History Survey (INHS) has had a strong focus on scientific collections. The INHS collections now total over 7.8 million specimens. Together with the almost 400,000 specimens from the University of Illinois collections that are managed by the Survey (see page 3), these holdings make up the second largest natural history collection in the state, and for most kinds of organisms are the most complete documentation of Illinois' flora and fauna available anywhere. This tremendous resource serves as the foundation for much of the Survey's research and educational programs. In this issue of INHS Reports, we provide an overview of the Survey's collections and their uses.

The INHS collections consist of specimens collected from throughout the world but with a strong emphasis on Illinois. They constitute a huge repository of biological information because a specimen consists not only of the preserved plant or animal itself, but also associated data. At a minimum, each specimen has with it information about where, when, and by whom it was collected; thus, the collections document the distribution of plants and animals through space and time. Additional data may also be recorded with the specimens or may be extracted if needed. For example, the size, age, and sex of the individual, its reproductive status, and what it had been feeding on may all be found for many animal specimens. Analyses can be run to determine levels of chemicals in plant or animal tissues, and DNA may be analyzed to determine relationships. This wealth of information makes collections invaluable for many scientific fields.

INHS researchers on a collecting expedition in 1894.

Traditionally, collections have been used primarily by systematists, scientists who study the diversity of life, particularly the evolutionary relationships among organisms, and determine appropriate names to be applied to populations. Using both morphology and molecular data, especially DNA, systematists determine the limits of species and develop classification schemes that reflect their relationships. Our knowledge about which species occur in Illinois depends on this use of collections.

Even in a state as well explored as Illinois, new species continue to be found. In some cases they are species that have invaded from elsewhere, but in other cases they are native species that have been overlooked by previous researchers. Without extensive collections, systematists would be unable to determine if unfamiliar species are newly discovered or are well-known species from other regions. This difference can have profound importance. A newly discovered species may need protection as a threatened or endangered species. An invader, by contrast, may require drastic control measures. The Asian longhorned beetle, which recently devastated hardwood trees in Chicago-area neighborhoods, is a good example. Information on this and other invasive species can be found in the November/December 1998 issue of INHS Reports.

Increasingly, scientists are using collections in ways other than to identify and classify organisms. Because the origin of each specimen can be fixed in space and time, changes in plant and animal distribution can be uncovered using collection data. Computerization of specimen data, coupled with the use of Geographic Information Systems (GIS), make changing patterns easier to determine. Repeated surveys, especially using established sampling techniques, allow even more detailed documentation of species distributions and community composition. Surveys of fishes in Illinois, which now span 100 years, are good examples. The results of the third statewide survey, soon to be published, show that our fish fauna has changed dramatically, with non-native species increasing and native species declining and even disappearing. The long-term monitoring efforts now under way through the Critical Trends Assessment Project will allow similar studies of other groups of organisms.

Nonscientists often ask why we maintain collections from earlier surveys. After all, once the name, date, and locality are recorded, why keep the specimen? The problem is that workers in different eras base their studies on different species concepts. For example, in his Fishes of Illinois, published in 1909, Stephen A. Forbes, a prominent scientist and first Chief of the Illinois Natural History Survey, assumed that many Illinois populations of small minnows with a prominent black stripe down their sides belonged to a species known as Notropis heterodon. Today, with improved information on Illinois populations, we know that what Forbes considered to be one species actually is three species. If we had only the published records, we would not know which localities were inhabited by which of the three species. Fortunately, by referring to the specimens that Forbes deposited in collections, we can determine the turn-of-the-century range in Illinois for each of the three species.

Not only can changes in species distributions be documented through collections, but so can changes in community composition. The red shiner is a small minnow that is common in the Great Plains and highly tolerant of warm turbid water. As riparian vegetation has been removed to create cropland, Illinois streams have become warmer and more turbid, and the red shiner has been able to move eastward across Illinois. Collection data from the late 1800s through 1998 show that as the red shiner has expanded its range, the related but less silt-tolerant spotfin, steelcolor, and blacktail shiners have become less common and less widely distributed in Illinois. Similar changes can be shown in crayfish communities, where the rusty crayfish, an invasive species introduced to Illinois about 1970, is spreading and rapidly increasing in numbers, whereas the clearwater and virile crayfishes, which occupy similar habitats, are showing declines, presumably because they are unable to compete with the larger and more aggressive rusty crayfish.

Targeting conservation efforts can be more effective with information from collections. Specimen data show that a few areas in Illinois support many more native species, often including rare species, than do other areas. These biologically outstanding areas therefore offer the best opportunities for protecting large numbers of native species. Gap analysis integrates information on these areas with GIS data on land ownership to identify "gaps" in protection. Because of its extensive collections and strength in GIS, INHS is the Illinois coordinator for the national gap analysis effort.

In a state like Illinois, which has so little high-quality natural habitat remaining, habitat restoration and even reconstruction are becoming increasingly important. Data on original species distributions and biological community compositions provide the benchmarks for projects designed to restore natural communities. Samples taken from project areas over time and preserved in the collections will allow us to measure their progress.

Changes in habitat quality can be demonstrated through collections in other ways. Often certain groups of species are particularly sensitive to environmental conditions, and are therefore good indicators of ecosystem health. Insects in the orders Ephemerop-tera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies), collectively referred to as EPT, are outstanding indicators of stream quality. Historical EPT collections, made prior to extensive degradation of Illinois' streams, are being compared with modern collections to document remaining high-quality streams and quantify the changes in others. In the future, collections made today will be used to show how changes in land management locally and statewide have affected stream quality.

INHS biologist Robert E. Richardson (left) and colleague collect fish in the Illinois River in 1910.

Sometimes collections can be used to document other forms of environmental change, notably the presence of chemical pollutants. Tissues extracted from specimens can be chemically analyzed, often with little damage to the specimens themselves. A classic example is the demonstration of increased DDT buildup in eggshells of several declining bird species, which is associated with thinning of the eggshells. This collection-based study contributed to the widespread ban of the use of this pesticide and the subsequent recovery of the bird populations. More recent studies have shown increases in other pesticides and heavy metals in fish and waterfowl. Without historical collections, made before the introduction of these pollutants, it would be impossible to demonstrate the changes they have caused.

The INHS collections are used not only by Survey staff but by scientists from around the country and the world. Much like books in a library, specimens in a collection can be studied either at the Survey or they can be borrowed for study at researchers' home institutions. In fiscal year 1997-1998, over 500 individuals visited the collections, and Survey staff sent out 172 loans totalling about 22,600 specimens. Researchers also get information via the collection Web sites and by requesting information directly from the curatorial staff; over 150 data requests were answered last year. In addition, the collections are widely cited in scientific publications. This intense use testifies to the importance of the INHS collections.

With continued modification of natural habitats and new ways to extract and utilize specimen data, the value of collections to society will increase. For many areas, the only records of a species' presence will be the specimens in institutional collections. Fortunately, INHS has collections that are among the largest and most valuable of any state-supported institution. The Survey is committed to building and preserving its collections, and making them and the associated data available to scientists, policy-makers, and the other citizens of Illinois concerned with protecting the environment.

Geoffrey A. Levin and Lawrence M. Page, Center for Biodiversity

Illinois Natural History Survey

1816 South Oak Street, MC 652
Champaign, IL 61820

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