Is there gold in trees in Finland?
The proverb “money doesn’t grow on trees” might need an asterisk. Scientists in northern Finland have found tiny gold nanoparticles inside the needles of Norway spruce trees. But this isn’t fairy gold—it’s a fascinating intersection of plant physiology, microbiology, and geochemistry. The latest study suggests that microbes living within the needles may help precipitate gold, turning soluble ions from the soil into solid particles.
This finding doesn’t mean forests are gold mines you can harvest with pruning shears. But it could revolutionize how we explore for minerals, make mining more sustainable, and deepen our understanding of how life shapes Earth’s chemistry.
Gold in Trees: The Study & Findings
Scientists from University of Oulu and the Geological Survey of Finland focused on trees growing above a known gold deposit near the Kittilä mine. They took 138 needle samples from 23 Norway spruce trees. Using field-emission scanning electron microscopy plus energy-dispersive X-ray spectroscopy, they identified solid gold nanoparticles in needles of 4 trees.
Parallel to that, they sequenced the bacterial communities inside those needles (16S rRNA). They found that certain bacterial taxa—like Cutibacterium and Corynebacterium—were more common in gold-positive samples. The gold particles often appeared adjacent to microbial biofilms, hinting that the microbes might foster the precipitation reaction.
While not every tree showed gold, the patterns suggest a microbe-assisted mechanism where internal microbes influence microchemical conditions (pH, redox) to turn dissolved gold ions into nano-sized solid particles.
Mechanisms & Hypotheses
Gold in crustal rocks weathers and releases ions into groundwater. Plants intercept water and dissolved elements via roots. Typically, trace metals travel through xylem to leaves. But what causes solid nanoparticles inside leaf tissue?
The hypothesis: within leaf tissue, microbial biofilms create localized microenvironments that shift chemistry (lowering solubility) and trigger precipitation of gold. The microbes may reduce or oxidize compounds, change pH, or bind ions via ligands, creating nucleation sites for solid gold formation.
If true, trees become not just passive accumulators of metals but living bioreactors in which microorganisms mediate mineral synthesis.
Biogeochemical & Exploration Implications
Mineral exploration already uses biogeochemical sampling—measuring metal concentrations from plants, soils, or water to infer subsurface deposits. What this study adds is that biomicrobial signatures inside plant tissue might refine sensitivity and specificity.
If specific microbes reliably co-occur with gold precipitation, then screening leaf microbiomes could provide a novel, minimally invasive exploration tool—reducing the number of blind drillings, cutting cost, and lowering environmental disturbance.
Extending further, this concept could apply to other metals (copper, platinum, rare earths) or even to phyto-remediation efforts that capture and precipitate toxins in plant tissues.
Gold in Trees: Limitations & Critical Considerations
The study on gold in trees is compelling—but preliminary. Key limitations include:
- Only 4 of 23 trees showed nanoparticles. Why the variation? Differences in microbiome, water routes, leaf age, or local microenvironment could matter.
- Correlation is not causation: microbial abundance and nanoparticle presence could both stem from some other factor.
- Detection sensitivity: instrumentation must distinguish gold signals reliably in biological tissue.
- Scaling: analyzing needles and microbiomes is labor-intensive and expensive; translating methods to large-scale exploration is nontrivial.
- Contamination and false positives: ensuring samples are not contaminated during collection, preparation, or imaging is critical.
Future experiments should isolate microbes, grow them in controlled settings with gold ions, and observe whether they precipitate gold nanoparticles in vitro.
Conclusion
While we know now that gold in trees is a real thing, we may not be able to shake gold bars from pine needles anytime soon. But this research opens a new lens on how life and mineral cycles interconnect. Trees and their microbial partners may shape not just ecosystems—but even subterranean chemistry.
If the process is validated, microbial-plant geochemistry could become a new frontier in sustainable exploration. We might trace veins of gold by leaf and genome instead of drilling holes in untouched land.
At its heart, this study reminds us how much we still don’t understand: that even within a simple spruce needle, hidden microbial alchemy may be turning invisible gold into something we can detect, study, and maybe one day harness.
Source: Earth.com
