Arbuscular mycorrhizal fungal-mediated reductions in N2O emissions were not impacted by experimental warming for two common pasture species.

Soil emissions of nitrous oxide (N 2 O), a potent greenhouse gas associated with agricultural systems, can be reduced by the activity of arbuscular mycorrhizal (AM) fungi. It is unclear, however, whether climate change may impact this ecosystem service provided by AM fungi. To assess the extent that warming may affect AM fungal mediation of N 2 O emissions from pastures, we grew lucerne (Medicago sativa , also called alfalfa) and tall fescue (Festuca arundinacea) under ambient (aT) and elevated (eT) temperature (+4 °C) regimes in the presence or absence of the AM fungus Rhizophagus irregularis. N 2 O emissions were measured from pots at five timepoints over a four-month period, while total plant biomass, nitrogen, phosphorus and mycorrhizal parameters (root length colonised and extraradical hyphal biomass in soil) were measured following a final destructive harvest. For both species, AM fungi significantly reduced N 2 O fluxes to a similar extent under both temperatures. The N 2 O reduction due to AM fungal inoculation was not influenced by warming. Overall, AM fungi were shown to reduce N 2 O emissions under current and predicted future warming scenarios for these two common pasture species, highlighting the role of microbial symbionts in mediating terrestrial feedbacks to future climate change. [ABSTRACT FROM AUTHOR]

Copyright of Pedobiologia is the property of Urban & Fischer Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)