Biology subjects

Picazo, A.

Publications and source records attributed to Picazo, A..

4 recordsLinked to original sources

bioRxiv2025

Does ecological restoration align prokaryotic community structure with natural references across European coastal wetlands?

AbstractCoastal wetlands are crucial for biodiversity and act as critical buffers for carbon sequestration and atmospheric greenhouse gases (GHG) concentrations, yet their degradation often turns them into GHG sources. Restoration is widely implemented to recover these services, but it remains unclear whether interventions successfully reestablish the microbial functional diversity underpinning biogeochemical cycles. We tested the hypothesis that restoration aligns prokaryotic community structure with natural references, analyzing, a European gradient of coastal wetlands, comparing well-preserved, altered, and restored sites in water and sediment. Using 16SrRNA-metabarcoding and IndVal-Analysis, we characterized community assembly identifying diagnostic functional consortia. Results revealed a marked difference in water and sediment recovery after restoration. Bacterioplankton communities rapidly converge to natural references, while sediment microbiome displayed significant "ecological memory". Restored wetlands show sediment communities structurally distinct from well-preserved, retaining alteration-associated guilds decades. Results support the initial hypothesis: restoration processes in coastal wetlands can re-establish communities and metabolisms resembling well-preserved conditions in the water in the short term, while sediments retain microbial communities and metabolisms inherited from altered conditions for a long time. Future strategies must integrate active sediment interventions using molecular bioindicators to validate not only the landscape appearance, but the effective reactivation of ecosystem processes and microbiota-related services.

ecology↗

bioRxiv2021

Metacommunities from bacteria to birds: stronger environmental effects in Mediterranean than in tropical ponds.

The metacommunity concept provides a theoretical framework that aims at explaining organism distributions by a combination of environmental filtering, dispersal and drift. With the development of statistical tools to quantify and partially isolate the role of each of these processes, empirical metacommunity studies have multiplied worldwide. However, few works attempt a multi-taxon approach and even fewer compare two distant biogeographical regions using the same methodology. Under this framework, we tested the expectation that temperate (mediterranean-climate) pond metacommunities would be more influenced by environmental and spatial processes than tropical ones, because of stronger environmental gradients and greater isolation of waterbodies. We surveyed 30 tropical and 32 mediterranean temporary ponds from Costa Rica and Spain, respectively, and obtained data on 49 environmental variables (including limnological, hydrogeomorphological, biotic, climatic, and landscape variables). We characterized the biological communities of Bacteria and Archaea (from both the water column and the sediments), phytoplankton, zooplankton, benthic invertebrates, amphibians and birds, and estimated the relative role of space and environment on metacommunity organization for each group and region, by means of variation partitioning using Generalized Additive Models (GAMs). Environmental selection was important in both tropical and mediterranean ponds, but markedly stronger in the latter, probably due to their larger limnological heterogeneity. Spatialized environment and pure spatial effects were greater in the tropics, related to higher climatic heterogeneity and dispersal processes (e.g. restriction, surplus) acting at different scales. The variability between taxonomic groups in spatial and environmental contributions was very wide. Effects on passive and active dispersers were similar within regions but different across regions, with higher environmental effects in mediterranean active dispersers. The residual (unexplained) variation was larger in tropical pond metacommunities, suggesting a higher role for stochastic processes and/or effects of biotic interactions in the tropics. Overall, these results provide support, for a wide variety of organisms related to aquatic habitats, for the classical view of stronger abiotic niche constraints in temperate areas compared to the tropics.

ecology↗

bioRxiv2020

Microbiome of the Black Sea water column analyzed by genome centric metagenomics

BackgroundThe Black Sea is the largest brackish water body in the world, although it is connected to the Mediterranean Sea and presents an upper water layer similar to some regions of the former albeit with lower salinity and (mostly) temperature. In spite of its well-known hydrology and physico chemistry, this enormous water mass remains poorly studied at the microbial genomics level. ResultsWe have sampled its different water masses and analyzed the microbiome by classic and genome-resolved metagenomics generating a large number of metagenome-assembled genomes (MAGs) from them. The oxic zone presents many similarities to the global ocean while the euxinic water mass has similarities to other similar aquatic environments of marine or freshwater (meromictic monimolimnion strata) origin. The MAG collection represents very well the different types of metabolisms expected in this kind of environments and includes Cyanobacteria (Synechococcus), photoheterotrophs (largely with marine relatives), facultative/microaerophilic microbes again largely marine, chemolithotrophs (N and S oxidizers) and a large number of anaerobes, mostly sulfate reducers but also a few methanogens and a large number of "dark matter" streamlined genomes of largely unpredictable ecology. ConclusionsThe Black Sea presents a mixture of similarities to other water bodies. The photic zone has many microbes in common with that of the Mediterranean with the relevant exception of the absence of Prochlorococcus. The chemocline already presents very different characteristics with many examples of chemolithotrophic metabolism (Thioglobus) and facultatively anaerobic microbes. Finally the euxinic anaerobic zone presents, as expected, features in common with the bottom of meromictic lakes with a massive dominance of sulfate reduction as energy generating metabolism and a small but detectable methanogenesis.We are adding critical information about this unique and important ecosystem and its microbiome.

microbiology↗

bioRxiv2017

Fine Stratification Of Microbial Communities Through A Metagenomic Profile Of The Photic Zone

Most marine metagenomic studies of the marine photic zone analyze only samples taken at one or two depths. However, when the water column is stratified, physicochemical parameters change dramatically over relatively short depth intervals. We sampled the photic water column every 15m depth at a single point of an off-shore Mediterranean site during a period of strong stratification (early autumn) to evaluate the effects of small depth increases on the microbiome. Using genomic assembly and metagenomic read recruitment, we found major shifts in the community structure over small variations of depth, with most microbes showing a distribution limited to layers approximately 30 meters thick (stenobathic). Only some representatives of the SAR11 clade and the Sphingomonadaceae appeared to be eurybathic, spanning a greater range of depths. These results were confirmed by studying a single gene (rhodopsin) for which we also found narrow depth distributions. Our results highlight the importance of considering vertical distribution as a major element when analyzing the presence of marine clades and species or comparing the microbiome present at different locations.

microbiology↗