DescriptionAquatic plants are used as a tool to enhance wetland biodiversity, because their species richness has positive correlation with aquatic invertebrate species richness and has been considered as spatial prey refugia for invertebrates. Yet, little is known about the effects of aquatic plant cover, i.e. the quantity of prey refugia, on invertebrate assemblages in predator-prey dynamics. Here we use diving beetles (Dytiscidae), an indicator taxon of wetland biodiversity, to investigate how emergent plant quantity affects invertebrate assemblages in ponds with and without predatory fish. In addition, we investigated the relationship between emergent plant cover and water depth, to give reliable management advice for biodiversity conservation. Our results showed different patterns at the pond level and the microhabitat level: At the pond level, dytiscid presence was positively correlated with increasing emergent plant cover, both with and without fish, revealing the importance of prey refuge quantity for prey species. At the microhabitat level, dytiscid species richness and abundance responded positively to increasing plant cover in ponds with fish, but there was no such relationship in ponds without fish. The different patterns at the microhabitat level indicate that prey species utilise microhabitats with and without prey refugia differently under different predation pressure. We discovered that emergent plant cover is negatively associated with water depth, suggesting shallow waters are needed to support emergent plants. We suggest providing variations in water depth and emergent plant cover to retain high habitat heterogeneity for freshwater biodiversity conservation.
|Period||8 Mar 2021|
|Event title||Spring Symposium 2021|
|Location||Helsinki/online, FinlandShow on map|