Namib Desert primary productivity is driven by cryptic microbial community N-fixation.

ABSTRACT: Carbon exchange in drylands is typically low, but during significant rainfall events (wet anomalies) drylands act as a C sink. During these anomalies the limitation on C uptake switches from water to nitrogen. In the Namib Desert of southern Africa, the N inventory in soil organic matter available for mineralisation is insufficient to support the observed increase in primary productivity. The C4 grasses that flourish after rainfall events are not capable of N fixation, and so there is no clear mechanism for adequate N fixation in dryland ecosystems to support rapid C uptake. Here we demonstrate that N fixation by photoautotrophic hypolithic communities forms the basis for the N budget for plant productivity events in the Namib Desert. Stable N isotope (δ15N) values of Namib Desert hypolith

SUBMITTER: Ramond JB 

PROVIDER: S-EPMC5932006 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature