CREAF

TITLE: "High phylogenetic turnover magnifies evolutionary relatedness along microbial primary succession"

DATE: Thursday, 16 November 2023.

TIME & FORMAT: form 12 to 1pm CET - In-person and online.

Seminars will combine in-person and online formats (CREAF, Sala Graus II, Universitat Autònoma de Barcelona, Spain) but in all cases, talks will be always streamed (not recorded), so they can be followed online.

HOW TO CONNECT: direct link to Marta Goberna's conference.

SUMMARY OF THE WORKSHOP:

Current models of microbial primary succession postulate that stochasticity dominates the early stages of community assembly. Theoretically, this generates phylogenetically random patterns that are lost as niche-based processes gain relevance. However, under severe abiotic stress, environmental filters may override stochasticity inducing phylogenetic clustering of soil bacterial communities, which may be magnified towards more carbon-rich mature stages due to intensified biotic interactions. To test this hypothesis, we collected 106 soil samples in seven mining deposits in drylands across ontogenetic gradients of 13 plant species that trigger primary succession and belong to four life forms (trees, shrubs, dwarf shrubs and perennial grasses).  

We analysed the phylogenetic community structure of soil bacterial communities using two metrics that quantify evolutionary relatedness of community members either across or at the tips of the phylogeny. Both metrics pointed to large levels of phylogenetic relatedness (clustering) and significantly departed from randomness indicating a negligible role of stochasticity. Each metrics responded to different plant and soil variables: Whole-level clustering varied across plant life forms based on their differential effect on soil moisture, while terminal clustering intensified along with plant growth following soil enrichment in organics and nutrients. Clustering intensified under an increased phylogenetic turnover during primary succession, due to the progressive dominance of large lineages composed of closely related organisms that were phylogenetically more and more distant to the initial communities. I will discuss the ecological processes operating at different evolutionary scales and the influence of bacterial lineages on each metrics. Our data help fine-tune current models of primary succession indicating that 1. environmental filters can override stochasticity from the early stages of primary succession, and 2. large levels of phylogenetic replacement can magnify evolutionary relatedness across gradients of community assembly.

ABOUT THE SPEAKER:

Marta Goberna Estellés is a biologist specialised in community ecology, particularly microbial ecology in terrestrial ecosystems. She combines metagenomics, phylogenetics and biochemical approaches to understand how belowground diversity and activity is organized and varies in time and space, responds to abiotic and biotic factors, and determines essential ecosystem functions. She holds a permanent position as a research scientist since July 2018 in the Department of Environment and Agronomy (INIA-CSIC). Since 2005, she developed my postdoctoral career in other four research centres in Spain (CEBAS-CSIC, CIDE-CSIC), Austria (Innsbruck University) and a short stay in Sweden (Swedish University of Agricultural Sciences). As Principal Investigator, she has managed 2.54 M€ in research projects and grants in four institutions, including an EU H2020-EJP Soil Project, two Marie Skłodowska Curie Individual-Driven Actions in Austria and Spain, as well as Spanish national and regional funds. Out of 63 papers in SCI journals, 56 have been published in the top quarter in their fields (published in e.g. Ecol Lett, ISME J, Global Ecol Biogeogr or Molec Ecol Res). She is Editor of Soil Biol Biochem, and member of the Spanish National Reference Centre on Soils, an advisory committee of the European Environment Agency.