New Phytol. (2025) 10.1111/nph.70515: “Decay stages of Jurassic wood debris from Scotland: evidence for the coevolution of fungal rot, arthropods and the nurse log strategy.” Stay with me here, this is very cool. “A key feature of extant conifer forests is the high percentage of seeds that germinate and establish on dead wood; in some forests, this can exceed 90%.” Such deadwood can serve as an ideal nursery for seedling tree species, which is why this type of seedbed is colloquially known as a ‘nurse log.’
The paper describes a “c. 150-million-year-old wood fragment from the Jurassic of Scotland using classic palaeobotanical techniques and microscopy + interprets our new finding within the evolution of gymnosperms with a literature review of fossil nurse logs, and fungal and arthropod evolution.”
There are 3 main stages. First is the breakdown of the wood by white pocket rot, then 2 stages of arthropod boring, likely by beetles [Darwin’s favorite] + mites, then colonization by young roots of the new young trees. “These findings demonstrate the complexity of decay processes occurring on a Jurassic forest floor, and the key role that white rot and arthropods play in the nurse log ecological strategy.”
Clearly conifer germination on nurse logs facilitated by white rot fungi is a conserved ecological strategy of relevance in shaping forest ecosystems over geological timescales. After all, conifers are the most diverse and widespread group of modern gymnosperms and have a fossil record extending over 300 million years (Myr). Living here in the Pacific Northwest, I can testify to the prevalence of nurse logs. Beautiful living specimens. But this fossilized example as pictured in New Phytologist is gorgeous as well.
