Stenotoleranza

Stenotoleranza, or stenotolerance, is a term used in ecology and environmental biology to describe the property of an organism to tolerate only a narrow range of an environmental factor or stressor. It stands in contrast to eurytolerance, where organisms endure wide variations. The concept applies to abiotic factors such as temperature, pH, salinity, and chemical pollutants, as well as to combinations of factors.

In practice, stenotolerant species occupy specialized niches and rely on relatively stable conditions. Their distributions are closely linked to the precise range of tolerable conditions; they are often more vulnerable to environmental change, habitat loss, or pollution than their more tolerant counterparts.

Common examples include stenothermal organisms (narrow temperature tolerance) and stenohaline organisms (narrow salinity tolerance). In microbiology, certain microorganisms exhibit stenotolerance to toxins or oxidative stress, resisting other conditions outside a narrow window.

Applications: In ecology and conservation, stenotolerance helps explain species’ vulnerability and endemism. In environmental monitoring, stenotolerant taxa can act as indicators of stable conditions or, when they decline, signals of disturbance. In toxicology, assessing stenotolerance informs risk assessment and remediation strategies that assume narrow safety margins.

Etymology: The term derives from the Greek stenos, meaning narrow, and tolerance; the Italian term stenotoleranza mirrors the concept.