Drivers of the biogeography of methanotrophs at a national scale: an insight into niche separation
Soil methane-oxidising bacteria (or methanotrophs) are responsible for the only biological removal of methane from the atmosphere. However, the major abiotic and biotic factors controlling the distribution of methanotrophs remain unclear; which in turns, limit the inclusion of taxa-based information to improve the predictions of global methane emissions under changing environments. In the present study, an innovative, hybrid geostatistical approach was implemented in order to identify the main predictors of soil methanotrophic community and map the distribution of methanotrophs at a national scale for the first time. Our findings suggest that the biogeography of methanotrophs is strongly influenced by land use and soil properties – such as soil moisture/rainfall, nutrients and heavy metals (copper in particular). Overall, our results confirm that methanotrophs, like other microbes with broader ecosystem functions, do not follow traditional macroecological concepts but instead can be defined in terms of niche separation, as in the old adage “everything is everywhere, but, the environment selects”. This paper suggests that the distribution of methanotrophs could be predicted under various ecological niches; hence this information may be useful to predict methane emissions under different potential climate change scenarios.