Evaluation of the floristic quality assessment and Oklahoma rapid assessment method for determining wetland condition

Floristic Quality Assessment (FQA) has become a widely adopted framework for evaluating ecological integrity, particularly in wetlands where vegetation provides a sensitive measure of anthropogenic disturbance and habitat quality. Chapter 1 synthesizes 71 peer-reviewed articles published between 1997 and 2023 to evaluate the methodological consistency, ecological applicability, and practical utility of FQA across regions, habitat types, and management contexts. While FQA remains a valuable and frequently implemented vegetation-based index, the review identified persistent challenges that limit its reliability across ecological gradients. Key limitations include the subjectivity and regional variability in assigning coefficients of conservatism (C-values), the confounding influence of natural environment gradients such as precipitation and soil conditions, and logistical barriers to comprehensive field implementation. Approximately 75% of studies reported fundamental or operational concerns, emphasizing the need for methodological standardization, broader calibration across underrepresented ecosystems, and clearer interpretive boundaries to strengthen the diagnostic precision of FQA. Building upon these findings, Chapter 2 evaluates the Oklahoma Rapid Assessment Method (OKRAM), a Level 2 rapid assessment tool designed to measure wetland condition across the state’s diverse ecological regions. Using data from 238 depressional and riverine wetlands spanning six ecoregions, this study compared vegetation sampling methods, accounted for natural variability within reference sites, and developed a calibrated vegetation multimetric index (VMMI) to improve condition scoring and validation. Quadrat sampling yielded higher and more consistent floristic and richness metrics than point-intercept, illustrating that sampling method influences FQA results. Ordination analyses revealed that precipitation strongly structured reference-site vegetation, confirming the need for ecological stratification in rapid assessment method (RAM) calibration. The resulting four-metric VMMI (incorporating native and perennial native cover, cover-weighted FQI, and hydrophytic richness) demonstrated stronger discrimination between reference and disturbed wetlands and higher concordance with OKRAM scores than the single metric FQI. Collectively, these chapters illustrate how addressing FQA’s methodological constraints informed the development of a multimetric index for Oklahoma wetlands, improving the ecological defensibility of RAMs and strengthening their application in long-term wetland monitoring and conservation.