A Source of Life

Springs are among the most biologically diverse ecosystems in the world, supporting a wide array of flora and fauna. The biodiversity of springs is all the more remarkable considering their size — for perspective, springs make up < 0.01% of the land area of North America. SSI staff regularly observe this hyper-diversity firsthand, commonly encountering 20-25% of regional plant species in springs surveys that may only cover about 7-13 acres in total. Springs support at least 10 percent of the endangered species in the United States, as well as thousands more rare, highly restricted, and endemic species. As oases in arid regions, springs are also an important resource for migratory species. At SSI, we see springs as "Noah's ark" habitats, protecting much of our biodiversity and natural heritage for future generations in tiny, isolated areas.

Springs-Dependent Species

While springs are a life-sustaining resource for many species, some taxa actually cannot survive without them. These springs-dependent species (SDS) are organisms that require springs habitat for at least one life stage. Some SDSs, such as many hydrobiid springsnails (more than 150 species in North America) and desert pupfish (Cyprinodontidae) occur only in springs sources and outflows. Others, from dragonflies and diving beetles to amphibians, fish, and other vertebrates, require springs habitats for reproduction, over-wintering (e.g., Florida manatees) or winter dormancy (e.g., some turtles). If a species cannot exist without springs habitat, it is considered springs-dependent.

Nationally, at least 10% of federally threatened and endangered species are springs-dependent. In addition to those federally listed species, we have documented more than 1,000 springs-dependent species. Most of these additional species have no formal protections, though many are rare and exclusively found in just a few springs. In our springs inventories, we regularly find aquatic and riparian invertebrate and vertebrate species that occur nowhere else in the landscape.

Use the links in the menu on the left to learn more about some of our favorite springs-dependent species.

Banner image by Molly Joyce