Bacterial Succession Decreases Network Complexity During Plant Material Decomposition in Mangroves

Abstract

In this study, 16S rRNA gene amplicon sequencing was used to assess bacterial diversity and dynamics throughout different stages of leaves decomposition of three plant species (Rhizophora mangle, Laguncularia racemosa, and Avicennia schaueriana) in three distinct mangroves of São Paulo state, Brazil. The experiments were conducted in microcosms. Phylogenetic diversity (Faiths' PD) index showed differences between samples and suggested that some treatments like R. mangle increased their bacterial diversity through time. Principal coordinate analysis revealed that community's profile varied based on mangroves, followed by plant species and time. A clear succession patterns was observed in this study, i.e., some microorganisms with low abundance in the initial phases gradually became dominant (e.g., Alphaproteobacteria), whereas microbes that were initially predominant became low (e.g., Gammaproteobacteria). Co-occurrence analyses were performed for all times of plant degradation aiming to better understand the relationships between bacterial populations. The c-score index was done to test the randomness of the community assemblage during the stages of decomposition. For all degradation time points, the values of the observed c-score were higher than the values of the simulated c-score. This result indicated that during plant decomposition, the bacterial communities presented less co-occurrence than expected by chance and that these communities were not randomly assembled but instead they are driven by species interactions. Network analyses results showed that in the conditions presented in this experiment, the initial stages of leaf decomposition formed more connected and complex networks than the later stages. These results suggest that resource competition was a determinant in these specific mangroves during plant degradation, mainly in the initial periods.

Co-occurrence patterns of litter decomposing communities in mangroves indicate a robust community resistant to disturbances

“…Environmental dynamics pose a challenge to the survival of nutrient cycling organisms in estuarine environments ( Holguin, Vazquez & Bashan, 2001 ). In the case of mangroves, sediments can be dry or submerged as well as subjected to fresh or marine environments ( Bouillon et al, 2004 ), which results in a complex microbial assemblage ( Freschet et al, 2013 ; Miura et al, 2015 ; Moitinho et al, 2018 ). In this study, we have applied litterbag experiments to unravel the effects that plant species has on the microorganisms that colonize their decaying leaves and to identify how the environmental characteristics affect this process.…”

“…In each of these mangroves, fresh and mature leaves (at the same phenological state) from the three main species of mangrove trees ( Rhizophora mangle, Laguncularia racemosa, and Avicennia schaueriana ) were sampled directly from the tree. The chemical composition of these leaves varies between species, R. mangle has the lowest hemicellulose and protein content and the highest lignin content, L. racemosa has the highest hemicellulose, and the lowest cellulose content while A. schaueriana has the highest cellulose and protein content (see Moitinho et al, 2018 for details). Field sampling was approved by the Biodiversity Authorization and Information System (SISBIO #20366-3).…”

Peer Review #1 of "Co-occurrence patterns of litter decomposing communities in mangroves indicate a robust community resistant to disturbances (v0.2)"

“…Environmental dynamics pose a challenge to the survival of nutrient cycling organisms in estuarine environments (Holguin, Vazquez & Bashan, 2001). In the case of mangroves, sediments can be dry or submerged as well as subjected to fresh or marine environments (Bouillon et al, 2004), which results in a complex microbial assemblage (Freschet et al, 2013;Miura et al, 2015;Moitinho et al, 2018). In this study, we have applied litterbag experiments to unravel the effects that plant species has on the microorganisms that colonize their decaying leaves and to identify how the environmental characteristics affect this process.…”

“…The use of network analysis has unveiled the relationships between populations and functions in the most diverse processes and habitats (Faust of mangrove trees (Rhizophora mangle, Laguncularia racemosa, and Avicennia schaueriana) were sampled directly from the tree. The chemical composition of these leaves varies between species, R. mangle has the lowest hemicellulose and protein content and the highest lignin content, L. racemosa has the highest hemicellulose, and the lowest cellulose content while A. schaueriana has the highest cellulose and protein content (see Moitinho et al, 2018 for details).…”

High-throughput amplicon sequencing reveals the spatiotemporal effects, abiotic and biotic shaping factors for the microbial communities in tropical mangrove sediments in Sanya, China

“…Microorganisms in mangroves are important. Universal studies on the structure and diversity patterns of microorganisms in mangrove sediments and leaves, including the communities of bacteria [5][6][7], archaea [7,8], and fungi [9][10][11], have shown that the microorganisms in mangroves are important element cyclers and nutrient providers, thus elucidating the microbial roles for mangrove ecological functions. As we know, comprehensive information for the biotic and abiotic processes across space and time needs to be established to fully understand ocean ecosystems [12].…”