What are Terrestrial Invertebrates?
Terrestrial invertebrate phlya of the Southern Appalachian region include arthropods such as spiders, insects, crustaceans, millipedes and centipedes; mollusks such as slugs and snails; annelids such as earthworms, and roundworms of the phylum Nemata.

Southeastern Species of Greatest Conservation Need Learn more about regional terrestrial invertebrate species of greatest conservation need by browsing our species information Web application.

Ecological Importance of Terrestrial Invertebrates
Terrestrial invertebrates are a food source for organisms such as birds, amphibians, and mammals. In addition, when they drop into streams, terrestrial invertebrates become an important component of stream fish diets, especially as aquatic invertebrate populations drop in the summer months (Sweka & Hartman, 2008, p.1). Furthermore, through pollination activities, invertebrates benefit flowering plants and the organisms that rely on them for habitat, food, or both.

In addition to their value as pollinators and an essential food source for many organisms, invertebrates are vital to functioning ecosystems, contributing to processes such as nutrient cycling and decomposition (Holmquist, 2004). Invertebrates also destroy excess productivity of plants, contributing to the overall health of the ecosystem through regulatory functions (Holmquist, 2004). By consuming seeds and foliage, invertebrates maintain balance in the ecosystem. As an example of the importance of insect regulation, lack of native insect predators makes the imported Kudzu vine a notorious ecological problem in the southeastern U.S.

Finally, invertebrates are often an essential link among trophic levels, which are reservoirs of energy stored within organic matter and linked by a food "chain" or "web." In many food webs, invertebrates serve as the crucial first links for transfer of food energy from the environment to other organisms. For example, by feeding on detritus, detritivores such as millipedes serve as a first step towards making nutrients within decaying organic matter available to higher trophic levels (Holmquist, 2004).

Terrestrial Invertebrate Sensitivity to Environmental Disturbance
Invertebrates are especially sensitive to environmental disturbance. Habitat loss from surface mining and logging activities as well as and pesticide use negatively impact invertebrate populations. Also, nitrogen deposition, habitat fragmentation, and pressure from exotic and invasive invertebrate species threaten invertebrate populations (Holmquist, 2004). These threats are particularly troublesome because diminished invertebrate populations can negatively impact other animals and plants through loss of the ecosystem services invertebrates provide, such as pollination, herbivory, predation, and consumption of plant seeds.

For more about terrestrial invertebrates, see the Web resources for terrestrial invertebrates on this page.