Lawrence Berkeley National Laboratory

Wetland restoration efforts in San Francisco Bay aim to rebuild habitat for endangeredspecies and provide an effective carbon storage solution, reversing land subsidencecaused by a century of industrial and agricultural development. However, the benefits ofcarbon sequestration may be negated by increased methane production in newlyconstructed wetlands, making these wetlands net greenhouse gas (GHG) sources to theatmosphere. We investigated the effects of wetland restoration on below-ground microbialcommunities responsible for GHG cycling in a suite of historic and restored wetlands in SF Bay. Using DNA and RNA sequencing, coupled with real-time GHG monitoring, we profiled the diversity and metabolic potential of wetland soil microbial communities. The wetland soils harbor diverse communities of bacteria and archaea whose membership varies with sampling location, proximity to plant roots and sampling depth. Our results also highlight the dramatic differences in GHG production between historic and restored wetlands and allow us to link microbial community composition and GHG cycling with key environmental variables including salinity, soil carbon and plant species.