Invertebrates and microbiota associated with aquatic macrophyte degradation in a shallow lake in southern Brazil

Abstract

Aquatic macrophytes are the main producers of organic matter in shallow aquatic ecosystems. They are also food sources for many herbivores. When macrophytes die, they enter the debris chain, are conditioned by microbial action and colonized by benthic invertebrates which remobilize nutrients from their biomass. In subtropical aquatic systems, the participation of shredder invertebrates has been questioned, highlighting the participation of fungi and bacteria in the degradation of organic matter. This study evaluated the degradation of two submerged aquatic macrophytes, Mayaca fluviatilis and Stuckenia pectinata, determining the quality of debris and microbiota and invertebrate trophic group density throughout the degradation process. Our results indicated that plants with lower polyphenol concentrations had higher degradation speeds. The shredders invertebrates had reduced abundance in both macrophytes, emphasizing the importance of bacteria and fungi in the nutrient cycling process in subtropical shallow lakes.

Enzymatic efficiency of the decomposing microbiota: what does really matter for aquatic macrophytes invasions?

“…Macrophyte biomass is preferably degraded by invertebrates and associated microbiota (Bornette & Puijalon 2011). The participation of shredder invertebrates in decomposition in tropical and subtropical aquatic systems has been questioned, highlighting the involvement of fungi and bacteria in the degradation of organic matter (Albertoni et al 2020). Moreover, a large portion of the macrophyte biomass, available in the form of litter, participates in microbial assemblage metabolism.…”

Bacterial decomposition of allochthonous organic matter in shallow subtropical lakes

“…Even with the vast distribution of shallow lakes on a global scale, ecological aspects such as nutrient cycling and energy flows through detritus are still poorly understood (Rezende et al, 2018). Although several studies have examined the processes of decomposition of native organic matter in these environments, few have studied the decomposition of allochthonous material (Albertoni et al, 2018(Albertoni et al, , 2020Bottino et al, 2019;Carvalho et al, 2015;Chen & Wang, 2019;Silva et al, 2018).…”