Springs as Ecosystems

Springs and spring runs represent a unique class of aquatic ecosystems typified by high water clarity and relatively constant water temperature and chemical conditions. Structurally, springs are best characterized by their basin morphometry (shape and volume), their position in the landscape, and their flora and fauna. A classic aquatic food web and biomass pyramid in spring ecosystems includes numerous primary producers and smaller numbers of primary and secondary consumers. Research has demonstrated that in their natural state, many springs are highly productive and persist in an approximate steady-state compared to most other aquatic ecosystems. During the past two centuries humans have been exerting an increasing variety of stresses on spring ecosystems in Florida. These external and internal stresses include decreasing groundwater supplies and increasing levels of nutrients, extensive recreational disturbance, and management alterations. Due to their physical and biological complexity combined with their adaptations to provide optimal levels of system productivity, a holistic ecosystem-level approach to spring studies is necessary to provide a greater understanding of anthropogenic effects (such as nutrient enrichment) on spring ecosystems. Development of a management strategy for springs will be dependent upon a better understanding of the relative importance and synergism of direct stressors at the local level and indirect stresses that occur at the regional scale. Systemslevel metrics have promise for providing a better understanding of the properties that many springs have in common. Use of ecosystem-level information is expected to provide a more sensitive indicator of the response of springs to nutrient increases and concurrent alterations due to the myriad other anthropogenic stresses.