Springs – neglected ecosystems

Posted on March 26, 2022

Springs can be defined as places on the Earth’s surface that are influenced by the exposure, and often the flow, of groundwater.  They support biodiverse ecosystems and have socioeconomic value as sources of water for drinking, agriculture, industry and recreation, , but they are often  highly vulnerable to human disturbance, such as groundwater depletion,  pollution, and habitat modification.  There are at least 2.5 million springs on Earth, but unfortunately springs have been poorly mapped, and a lack of a suitable classification system has hampered studies on their diversity, distribution, ecology, and conservation status.  As a result, public awareness of springs is limited and this has allowed them to become increasingly threatened.  To assist in management planning, scientists in Arizona, U.S.A. have developed a springs ecosystem model and a classification system based on landform features.  They provide a dichotomous key for the identification of 12 major types of springs, and report that in testing the key on 244 springs, 88% were classified correctly.  The key includes factors relating to contact between groundwater and surface water, and the landform, habitat structure and ecology of the emerging spring and its downstream flow.  The researchers maintain that classification approaches based on factors other than landform (such as aquifers, flow, water quality, landscape location, and biota) aren’t precise enough to distinguish different types of springs.  Several different microhabitats can occur within a single spring (especially spring types such as hanging gardens and hillslope springs), and this has a positive impact on biodiversity and ecological complexity.  The classification shows how different types of springs are related and how landform affects ecological communities.  It also highlights where rare or endemic species are likely to occur, and clarifies management options relevant to particular types of springs.

Reference:  Stevens, L.E. et al. 2021.  Springs ecosystem classification. Ecological Applications, 31(1),  e02218. https://doi.org/10.1002/eap.2218