EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Climate history dictates microbial metabolic response to drought stress: from semi-arid soils to tropical forest precipitation gradients 

Nicholas Bouskill1, Ulas Karaoz1, Stephany Chacon1, Aizah Khurram1, Lee Dietrich2, Hoi-Ying Holman3, and Daniela Cusack2,4
Nicholas Bouskill et al.
  • 1Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, United States of America (
  • 2Department of Ecosystem Science and Sustainability, Colorado State University, Campus Delivery 1476, Fort Collins, CO, 80523, USA.
  • 3Berkeley Synchrotron Infrared Structural Biology Program, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720
  • 4Smithsonian Tropical Research Institute, Apartado, 0843-03092 Balboa, Ancon, Republic of Panama

The frequency and intensity of environmental fluctuations play an important role in shaping microbial community composition, trait-distribution, and adaptive capacity. We hypothesize here that a communities’ climate history dictates it’s metabolic response to future perturbation under a changing climate. Such a response is significant as changes in microbial metabolism can, in turn, feedback onto metabolite exudation, the chemical structure of necromass, and the formation and stability of soil organic matter. Here we use laboratory and field experiments to examine the metabolic pathways invoked under osmotic and matric stress within semi-arid and tropical soils. For example, using non-destructive, synchrotron-based Fourier-transform infrared spectromicroscopy we profiled the stress response of phylogenetically similar bacteria isolated from soils with contrasting climate histories subjected to both matric and osmotic stress. We note a strong carbohydrate-based, metabolic response of tropical microbes that is entirely absent in semi-arid organisms. At the field scale, we use metagenomic sequencing and metabolite analysis to demonstrate how four different sites established across a 1 m precipitation gradient from the Caribbean coast to the interior of Panama respond to a 50 % reduction in throughfall. The precipitation gradient permits the development of distinct communities at each site that show clearly divergent response to imposed hydrological perturbation. Our contribution here will discuss how communities adapted to different precipitation regimes respond metabolically to drought conditions, and how these change feedback onto the structure and stability of soil organic matter.    

How to cite: Bouskill, N., Karaoz, U., Chacon, S., Khurram, A., Dietrich, L., Holman, H.-Y., and Cusack, D.: Climate history dictates microbial metabolic response to drought stress: from semi-arid soils to tropical forest precipitation gradients , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1233,, 2022.

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