Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017

Erindi/veggspjald / Talk/poster E16

The role of microbial dormancy in soil carbon-climate feedbacks

Höfundar / Authors: Alejandro Salazar (1,2), Evgenia Blagodatskaya (3), Benjamin N. Sulman (4), Jay T. Lennon (5), and Jeffrey S. Dukes (1,2,6).

Starfsvettvangur / Affiliations: 1. Dep. Biological Sciences, Purdue University, IN, USA, 2. Purdue Climate Change Research Center, IN, USA, 3. Dept. Soil Science of Temperate Ecosystems, University of Göttingen, Göttingen, Germany, 4. Program in Atmospheric and Oceanic Sciences, Princeton University, NJ, USA, 5. Dept. Biology, Indiana University, IN, USA , 6. Dept. Forestry and Natural Resources, Purdue University, IN, USA

Kynnir / Presenter: Alejandro Salazar

Global soil respiration is the largest flux of carbon from terrestrial ecosystems to the atmosphere, and it is increasing with warming at a rate of ca. 100 million tons of C y-1. To know whether this trend will accelerate, stabilize, or decrease, we need to understand how are soil microbes (the main drivers of soil respiration) responding to climate change and what are the consequences of these responses for soil carbon cycling. We investigated how and when soil carbon (C) responses to climate are associated with changes in the metabolic state (i.e. between active and dormant) of soil microbial communities. We found that activation of dormant microbes contributes to explains soil respiratory responses to temperature and moisture at different spatial (i.e. microcosms and field experiments) and temporal (i.e. hours to months) scales, and in soils from different ecosystems and latitudes. We modified the structure of a soil carbon model to account for the capacity of microbes to enter and exit dormancy, and calibrated it based on empirical observations. We found that when dormancy is not considered, microbial biomass and respiration are over suppressed by environmental stress, especially under warming and long dry periods. Overall, our results suggest that as the Earth keeps getting warmer, and in many places the dry periods between wetting events keeps getting longer, microbes in soil will respire more than would be predicted by models that do not take dormancy into account.