Use of Plant Species as Environmental Indicators

Biological indicators are defined based on the specific responses of organisms to their environment. For plants, several classification systems have been developed; among the most widely used is Ellenberg’s Ecological Indicator Values (EIVs). EIVs assign ordinal scores to species along major environmental gradients and allow inference of site conditions from species composition. Ellenberg proposed indicator values for seven factors; light (L), moisture (F), soil reaction (R), nitrogen (N), salinity (S), temperature (T) and continentality (K) derived from species’ realized niches. Site (community) indicator values are commonly calculated by weighted averaging of species indicator values using cover/abundance data, and the resulting means are interpreted within recommended value ranges. In Europe, EIVs have been used extensively to characterize vegetation types and to track ecological change; in Turkey their use is increasing but still limited, and values transferred from Central Europe may not always reflect local conditions. Estimating indicator values from regional floristic data can provide a practical, low-cost alternative to time-consuming field measurements and support assessments of environmental gradients and the magnitude of ecological change.