Time lags in the regulation of symbiotic nitrogen fixation.

ABSTRACT: Theory has shown that time lags in the regulation of symbiotic nitrogen (N) fixation (SNF) can be important to the competitive dynamics and ecosystem consequences of N-fixing trees, but measurements of these time lags are lacking. Here, we used a novel method to measure SNF in seedlings of four N-fixing tree species that represent tropical and temperate origins and actinorhizal and rhizobial symbiotic associations, each grown under warm and cold temperature regimes. We added N to previously N-poor pots to induce downregulation and flushed N out of previously N-rich pots to induce upregulation. It took 31-51 d for SNF to decline by 95%, with faster downregulation in temperate species and at warm temperatures. Upregulation by 95% took 108-138 d in total, including 21-57 d after SNF was first

SUBMITTER: Bytnerowicz TA 

PROVIDER: S-EPMC12267930 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature