The relevance of environment vs. composition on dissolved organic matter degradation in freshwaters

Authors

Núria Catalán Ada Pastor Carles M. Borrego Joan Pere Casas‐Ruiz Jeffrey A. Hawkes Carmen Gutiérrez Daniel von Schiller Rafael Marcé

Dissolved organic matter (DOM) composition exerts a direct control on its degradation and subsequent persistence in aquatic ecosystems. Yet, under certain conditions, the degradation patterns of DOM cannot be solely explained by its composition, highlighting the relevance of environmental conditions for DOM degradation. Here, we experimentally assessed the relative influence of composition vs. environment on DOM degradation by performing degradation bioassays using three contrasting DOM sources inoculated with a standardized bacterial inoculum under five distinct environments. The DOM degradation kinetics modeled using reactivity continuum models showed that composition was more important than environment in determining the bulk DOM decay patterns. Changes in DOM composition resulted from the interaction between DOM source and environment. The role of environment was stronger on shaping the bacterial community composition, but the intrinsic nature of the DOM source exerted stronger control on the DOM degradation function.

Postdoc and Ph.D. studentship (Community ecology), Georgia Institute of Technology, GA, USA

Postdoctoral position in community ecology available at Georgia Tech

A postdoctoral scientist position is available in Lin Jiang’s laboratory at the School of Biological Sciences of Georgia Institute of Technology (https://biosciences.gatech.edu/people/lin-jiang). The postdoc will work on a NSF-funded project investigating the role of phylogenetic diversity for community assembly and ecosystem functioning. The project primarily involves conducting laboratory microcosm experiments with bacteria and bacterivorous protists. In addition to working on the project, the postdoc will be encouraged to develop his/her own research program. Applicants should have earned (or will soon earn) a Ph.D. in community ecology, microbial ecology, or related fields. Competitive salary and benefits are provided. The position is available from January 1, 2021. The appointment will be for one year initially, and may be extended for a second year (pending performance). Applicants should electronically send an application package including a statement of research interests, a CV, and contact information of three references to me at lin.jiang@biology.gatech.edu. Potential applicants are encouraged to contact me for more information.

Ph.D. student opportunities in community ecology available at Georgia Tech

I am seeking 1-2 highly motivated Ph.D. students to join my laboratory at the School of Biological Sciences of Georgia Institute of Technology, in Fall 2021. My primary research interests are in community ecology (see more information at https://biosciences.gatech.edu/people/lin-jiang), and students interested in community ecology and related fields should apply. The successful candidates will have the freedom to choose their study systems (laboratory, field, or theoretical) and develop their own research projects during their graduate studies. Competitive stipends are provided in the format of research and teaching assistantships, with graduate fellowships also available for outstanding students. Note that as of fall 2020, GRE is no longer required for admission to our graduate program; the application deadline is Dec 15, 2020. For more information about our graduate program and online application, please go to https://biosciences.gatech.edu/graduate/prospective-students. Potential applicants may wish to contact me (Lin Jiang; email: lin.jiang@biology.gatech.edu) prior to filing an application.