Scientists Discover Orchids Sprouting from Decaying Wood, Revealing a Hidden Carbon Pathway
KOBE, Japan – October 8, 2025 – The secret to an orchid's start in life has been found in an unexpected place: rotting logs. A new study from Kobe University reveals that orchids, known for their delicate beauty, depend on partnerships with wood-decaying fungi to germinate, unlocking carbon from deadwood to fuel their growth.
Orchid seeds are as tiny as dust and lack the nutrient reserves of most seeds. While it was known that adult orchids often partner with fungi, the germination process in the wild has remained largely a mystery. "Studying orchid germination in nature is notoriously difficult," explains Kenji Suetsugu, a plant evolutionary ecologist at Kobe University who led the research.
The breakthrough came from a simple observation during fieldwork. "We repeatedly found seedlings and adults with juvenile root structures near decaying logs, not scattered randomly in the forest," Suetsugu says. "That recurring pattern inspired us to test whether deadwood fungi fuel orchid beginnings."
Closing the Loop on Orchid Ecology
To solve this mystery, the team buried seeds of four orchid species in various forest locations. The results, published in the journal Functional Ecology, were striking: germination occurred only near decaying logs. DNA analysis confirmed that the seedlings were exclusively associated with wood-decomposing fungi.
The research also uncovered a consistent link between the fungi found in seedlings and those in adult plants that retain coral-shaped rhizomes—seemingly a remnant of their seedling stage. "We think that plants without these rhizomes shift to other fungi as their nutritional needs change and the carbon source from rotting logs dries out," Suetsugu notes.
Implications for Evolution and Conservation
This discovery has far-reaching consequences. It explains how certain orchid species evolved to become fully "mycoheterotrophic"—abandoning photosynthesis entirely and relying on fungi for their entire lives. "The propensity of these orchids to maintain their association with wood-decaying fungi into adult life probably facilitated this evolution," says Suetsugu.
For conservationists, the message is clear. "Protecting orchids in the wild is inseparable from protecting deadwood and its fungi," Suetsugu emphasizes. Ecologically, the study reveals a previously hidden carbon route from deadwood to green plants, fundamentally changing how we view nutrient cycling in forests.
As Suetsugu poetically concludes, "Deadwood is not dead—it is a cradle of new life."
This research was funded by the Japan Science and Technology Agency, the Japan Society for the Promotion of Science, and the Research Institute for Humanity and Nature.