Biota

Animals | Plants | Fungi | Microorganisms | References

Earth's diversity of living organisms or biodiversity includes approximately 1.5 million named species. Biologists, however, recognize that this number falls far short of the actual number of species. Attempts to estimate the total number of species usually take into account the proportion of new species in carefully studied samples from tropical rain forests or other high diversity areas. Specialists in groups like insects and microorganisms estimate that the number of species probably lies somewhere between 5 million and 100 million species. In other words, we don't really know how many species inhabit our planet! What can be said with certainty, though, is that the number of species is very large, and we have not yet discovered most of them. Mammals, birds, and reptiles are exceptions - we have named nearly every species in these groups. By contrast, millions of species of insects and their relatives await description and names by scientists.

Taxonomy- The science of naming and classifying organisms

Every known species is given a unique two-part scientific name in Latin. The system for naming species was introduced by the Swedish botanist Carolus Linnaeus in the 1700's and is used today all over the world. The first part of the name (e.g., Homo) gives the name of the genus - a group of closely related species. The second part of the name or epithet (e.g., sapiens) gives a unique name within the genus. In order to be accepted for use, the scientific name (e.g., Homo sapiens) must be introduced formally in a publication that is reviewed by experts in the appropriate group of organisms. The importance of unique scientific names can be demonstrated by a familiar example. In Europe, the bird called a "robin" is not the same robin that occurs in North America. While these two different birds share a common English name, their scientific names are different. (In the case of birds, formal English names also are used - American Robin, European Robin, etc. - but scientific names remove all confusion.)

Grouping species into taxonomic categories (taxa) helps us recognize similarities among organisms and reflects our understanding about evolutionary relationships. The most widely used system of classification includes seven major categories. The example below describes the taxonomic classification of the Monarch Butterfly:

*The category Division is commonly used for plants

Intermediate categories (e.g., Subphylum, Subfamily) are commonly used for taxa with many or particularly distinct members. Note that scientific names are always written in italics or underlined. The first letter of the genus name is capitalized, while the epithet is not capitalized.

Biodiversity of the Northern Lake States

Compared with other parts of the world, the number of species in the Great Lakes Region is relatively small, and the species present tend to be widespread throughout eastern North America. The reason for our modest regional biodiversity is historical. Approximately 10-15,000 years ago, near the end of the most recent Ice Age, all but a few places in this region were covered with permanent snow and ice. Most of the plants and animals that had previously inhabited Minnesota, Wisconsin, and Michigan were unable to survive here during the Ice Age and either perished or migrated south to milder, unglaciated areas. As the climate eventually became milder, species began to re-colonize our region. In fact, research by Dr. Margaret Davis at the University of Minnesota and others suggests that some slow-dispersing species (e.g., certain trees) are still "migrating" into parts of the Northern Lake States. On the other hand, migratory breeding birds (which can easily fly great distances) provide an exception; our region supports one of the richest songbird faunas in North America.

Even though our biodiversity is not as great as that of tropical rainforests and other areas, the Northern Lake States are home to tens of thousands and perhaps hundreds of thousands of species, including many (mostly microorganisms) that have not yet been given names and many others that are poorly known. A single handful of soil, for example, might contain more than 5,000 species of species of arthropods, nematodes, and bacteria (Wilson 1992), few of which have been studied carefully by scientists.

Learning about local biodiversity

Knowledge about local biodiversity enriches our lives in many ways. Besides helping us appreciate the natural environment, biodiversity "literacy" has countless practical applications.

• Farmers improve profits and reduce environmental impacts when they are aware of local pest species and natural predators that help prevent outbreaks.
• Homeowners and landscapers create more interesting lawns and gardens when they incorporate native plants and animals into residential designs.
• Teachers and outdoor educators have a stronger impact on students when they use specific examples from the local environment.
• Resource managers like foresters, wildlife managers, and fisheries managers are better able to maintain sustainable harvests when they are knowledgeable about species interactions and local ecosystem processes.
• Engineers promote cheaper and more efficient pollution control when natural features like wetlands and native aquatic organisms are incorporated in project planning.
• Conservation biologists are more successful in protecting rare species and natural communities when they recognize threats by exotic species.

A major goal of the Cofrin Arboretum Center for Biodiversity and this web site is to provide biodiversity-related information that helps improve the lives of people in the Great Lakes region while protecting the natural environment on which we and our descendants depend.