Isotopic pulse-labelling of photosynthate allows tracing of carbon (C) from tree canopies to belowground biota and calculations of its turnover in roots and recipient soil microorganisms. A high concentration of label is desirable, but is difficult to achieve in field studies of intact ecosystem patches with trees. Moreover, root systems of trees overlap considerably in most forests, which requires a large labelled area to minimize the impact of C allocated belowground by un-labelled trees.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2024
There are growing doubts about the true role of the common mycorrhizal networks (CMN or wood wide web) connecting the roots of trees in forests. We question the claims of a substantial carbon transfer from 'mother trees' to their offspring and nearby seedlings through the CMN. Recent reviews show that evidence for the 'mother tree concept' is inconclusive or absent.
View Article and Find Full Text PDFSeminal scientific papers positing that mycorrhizal fungal networks can distribute carbon (C) among plants have stimulated a popular narrative that overstory trees, or 'mother trees', support the growth of seedlings in this way. This narrative has far-reaching implications for our understanding of forest ecology and has been controversial in the scientific community. We review the current understanding of ectomycorrhizal C metabolism and observations on forest regeneration that make the mother tree narrative debatable.
View Article and Find Full Text PDF