In this interactive activity from the American Museum of Natural History, explore representations of three habitats within Africa's Dzanga-Sangha rainforest. Follow clues that reveal how its resident animals, plants, and people depend on one another. The challenge requires users to play "connect the dots" to identify feeding relationships, and highlights animal behaviors and natural resources within the ecosystem.
Biodiversity refers to the richness, or variety, of life on our planet. The total number of different plants, animals, and microorganisms today—estimated to be at least 10 million—is the product of more than three billion years of evolutionary history. Groups of species that perform similar roles in a given ecosystem are known as functional types. Species may be organized into functional types based on factors such as what they consume or their place in the food web as producers, consumers, or decomposers.
Certain species, called keystone species, have a disproportionate impact on the ecosystems they live in. Consequently, the loss of keystone species creates a more significant impact through an ecosystem than does the loss of its other inhabitants. This does not mean that other inhabitants are insignificant. At first glance, some species appear to have trivial niches. However, often these inhabitants have important functions that involve other species. For example, when a plant disappears from an ecosystem, it can take with it up to 30 other species, including other plants, insects, and even higher animals.
Healthy ecosystems perform many functions that benefit all its inhabitants. They purify the air, filter harmful substances from water, convert decaying matter to nutrients, and moderate erosion and flooding. Research indicates that declining biodiversity can lead to an overall decline in ecosystem functioning. By contrast, an ecosystem with more species is likely to be more stable than one that has fewer species. For example, grassland plots with a greater number of plant species are better able to withstand drought than those with less species diversity.
Through statistical analysis of extinction and diversification in the fossil record, we know that biodiversity is slow to recover after an extinction event. One possible explanation for this is that extinction does not just eliminate species or groups of species, it also removes the roles that those species play within ecosystems. Recovery becomes more complicated because specialized roles—such as the way some parasites live on just one species, or the fact that certain animals consume just one kind of food—do not evolve until their hosts are already well established.
Ultimately, we humans derive most of our food, shelter, and clothing, as well as medicines and industrial products, from biological sources—and these biological sources contribute to the proper functioning of the ecosystems we inhabit. This brings up an important question: How should we act knowing that numerous life forms are vanishing—or in danger of vanishing—from our planet?
Academic standards correlations on Teachers' Domain use the Achievement Standards Network (ASN) database of state and national standards, provided to NSDL projects courtesy of JES & Co.
We assign reference terms to each statement within a standards document and to each media resource, and correlations are based upon matches of these terms for a given grade band. If a particular standards document of interest to you is not displayed yet, it most likely has not yet been processed by ASN or by Teachers' Domain. We will be adding social studies and arts correlations over the coming year, and also will be increasing the specificity of alignment.