A new method for detecting and interpreting biodiversity and ecological community thresholds

1. Existing methods for identifying ecological community thresholds are designed for univariate indicators or multivariate dimension-reduction of community structure. Most are insensitive to responses of individual taxa with low occurrence frequencies or highly variable abundances, properties of the vast majority of taxa in community data sets. We introduce Threshold Indicator Taxa ANalysis (TITAN) to detect changes in taxa distributions along an environmental gradient over space or time, and assess synchrony among taxa change points as evidence for community thresholds. 2. TITAN uses indicator species scores to integrate occurrence, abundance and directionality of taxa responses. It identifies the optimum…

• UE
  U.S. Environmental Protection Agency