What is Ecological Conservatism? A Template Analysis of Its Definitions

Conservatism is the concept underlying Floristic Quality Assessment (FQA), a method used to reflect conservation value and ecological condition based on plant communities. The inputs to FQA metrics are coefficients of conservatism (C-values), values ranging from 0 to 10 that are assigned to individual species by experts. Conservatism is generally characterized as a species' fidelity to less-degraded remnant natural areas as determined by their sensitivity to human disturbances. However, because conservatism is sometimes broadly and dissimilarly defined in the literature, without systematic study or review, its definition has become unclear to users. We used template analyses to search for key terms in definitions of conservatism from 51 documents that described the establishment of C-values in new regions. Tolerance to “disturbance” was the most frequent term used to define conservatism, being found in over half of the documents. We then outlined the underappreciated complexities of “disturbance” when defining conservatism. Other prominent phrases included fidelity to natural areas, remnants, or specific habitats, and intolerance of human disturbance. Descriptions of species with lower C-values (0–3) often included ruderality, tolerance of heavy disturbance, and adaptation to a broad range of environmental conditions. Midrange C-values (4–6) generally related to “intermediate” conditions, dominant matrix species, and tolerance of moderate disturbance. Descriptors of advanced succession, narrow environmental tolerances, and fidelity to “high-quality conditions” were captured in higher C-values (7–10). These results reveal how researchers have variously interpreted ecological conservatism, particularly with respect to ecological concepts such as succession and specialization. We advocate for explicit, upfront, and consistent definitions of conservatism when establishing C-values in new regions and when refining existing values. When defining or using conservatism, we suggest special attention should be given to two foundational pillars of the concept: fidelity and tolerance.