Use of a morphology-based functional approach to model phytoplankton community succession in a shallow subtropical lake

1.We use morphology-based functional groups (MBFGs) of phytoplankton to predict ecological performance of groups with a mechanistic model. We evaluate MBFGs' performance in relation to hypothetical examples of succession and compare it with empirical data for a shallow subtropical hypertrophic lake (Lake Rodo, Uruguay). 2.Our model predicts a trade-off between maximum growth rate (max) and competitive ability (Tilman's R*) for most MBFGs. The model predicts that phytoplankton succession will proceed from groups with high surface/volume, high max and without specialised structures (opportunists) towards the dominance of large colonial or filamentous algae with lower max and specialised traits (gleaners). These predictions are generally congruent with empirical data for Lake Rodo. 3.The MBFG classification explained ecological performance of phytoplankton community dynamics while reducing system dimensionality. Despite species aggregation, MBFGs can resolve the occurrence of potentially noxious groups and thus is a promising tool for understanding and managing ponds and lakes.