Antagonistic and cumulative effects of connectivity: a predictive model based on aquatic vegetation in riverine wetlands

The effects of connectivity cannot be reduced to a simple gradient. River overflows disturb the vegetation of connected wetlands but, reducing competition, promote plant diversity, Overflows also bring nutrients, silt and plant propagules. Nutrients increase eutrophication and promote phytoplankton development, which reduces water transparency and impedes the growth of rooted plants. Silt inputs accelerate terrestrialization but provide regeneration niches that favour the recruitment of allochthonous propagules. These multiple effects are combined into a model that predicts diversity and life-history traits of aquatic plants (growth form, potential size, phenology and frequency of flowering, vegetative reproduction and defence against herbivores) in relation to the connectivity of the riverine wetlands.