Modeling the long-term population dynamics of benthic foraminiferal communities using field and experimental data

Abstract

A mathematically simple model is used to simulate the long-term impact of variable food flux and oxygenation over decades. [nput characteristics were offspring and generation length, the values of which are derived from laboratory experiments. Other input consisted of a parameter describing the sensitivity of taxa to variation in oxygenation; values for this constant were derived from field data. A fourth parameter describing sensitivity to competition was obtained by inverse modeling. We simulated a 30 years time series with initially high eutrophication and low oxygen values. The model showed that opportunistic taxa, characterized by a high reproductive success, could successfully compete in environments marked by periodically occurring severe oxygen stress. Under permanent low oxygen conditions they were replaced by deep infauna. Under improved environmental conditions, the assemblage was dominated by taxa that are adapted to food-limited conditions. Oxygen appeared to be a more important parameter than food in the recovery of the ecosystem after an initial eutrophic state. The simulated sequences were compared with the historic development of the Adriatic Sea over the past 160 years, which also documents a change between trophic extremes.