Impact of curve construction and community dynamics on the species-time relationship.

The species-time relationship (STR) describes how the species richness of a community increases with the time span over which the community is observed. This temporal scaling provides insight into theoretical questions on species diversity patterns as well as applied questions on the appropriate time scale for biodiversity assessments. To better understand STRs, we discuss the methods used to construct STRs in the literature and derive the impact of curve construction on STR properties. Using vegetation data from Mount St. Helens, Washington, USA, we illustrate the sensitivity of the STR to construction under colonization-dominated dynamics. This study highlights the importance of considering the type of STR when interpreting, comparing, and applying STRs, particularly in disturbed or successional systems.