Fig trees are revolutionizing our understanding of how some trees can mitigate climate change. in much more effective ways than previously thought. Not only do they absorb carbon dioxide (CO2) as part of photosynthesis, but certain species have demonstrated the surprising ability to transform this gas into stable minerals, thus contributing to soil improvement and reducing atmospheric CO2.
This fascinating process has captured the attention of scientists and environmental engineers., as it could redefine global strategies for reforestation and sustainable agriculture. Here, we detail how the mechanism works, which species are at the center, and how this phenomenon could be applied to regenerate soils and produce food at the same time.
How do fig trees convert CO2 into rock?
The biological process that allows some fig trees to transform CO2 into solid substances it is known as oxalate-carbonate pathwayUnlike most trees, which store carbon in organic form within their biomass, some fig tree species convert some of this CO2 into hard minerals, such as calcium carbonate, which become embedded in their structure and the surrounding soil.
The operation can be summarized in three crucial stages:
- CO2 absorption through photosynthesis, fixing atmospheric carbon in its metabolism.
- Conversion of part of the absorbed carbon into microscopic crystals of calcium oxalate within its tissues.
- Transformation of these crystals into calcium carbonate by the action of microorganisms present in the soil, resulting in stable and long-lasting mineralization.
The calcium carbonate obtained is the same substance that forms chalk and limestone., but in this case, it is produced naturally and renewably within or around the fig trees themselves.
The oxalate-carbonate pathway: details of the biochemical process
The oxalate-carbonate pathway is one of the most advanced forms of inorganic carbon sequestration known in terrestrial environments.Unlike accumulated plant matter, which can release CO2 when it decomposes, carbon trapped as calcium carbonate remains in the soil for centuries or even millennia.
This process begins when the fig tree fixes CO2 and uses it to synthesize oxalates. These oxalates combine with calcium in the soil to form calcium oxalate crystals in the bark and wood tissues. Specific bacteria and fungi in the environment subsequently break down these crystals, releasing ions that react and precipitate as calcium carbonate.Therefore, part of the fig tree literally turns to stone.
The result is a much more permanent CO2 storage. and resistant to environmental degradation than any other known form of conventional plants.
Ecological and agricultural benefits of inorganic carbon sequestration
The process carried out by African fig trees provides a series of high-value ecological and agricultural advantages, which are added to their classic function as fruit trees:
- Long-term carbon sequestration:CO2 converted into calcium carbonate remains stable for centuries, contributing significantly to the reduction of greenhouse gases.
- Improving soil fertility and healthBy raising the soil pH, carbonates release essential nutrients, making the land more fertile and suitable for other crops.
- Sustainable food productionFig trees not only capture carbon, but also produce edible fruit, combining ecological and economic function in a single tree.
This dual function places the fig tree as a key pillar for models of regenerative agriculture and sustainable agroforestry.
Ficus wakefieldii, the most efficient species at transforming CO2
Among the species studied, Ficus wakefieldii stood out for its extraordinary mineralizing capacity.During research conducted in Samburu County, Kenya, this fig tree was able to store CO2 in much larger quantities than the other species tested.
The most striking thing is that calcium carbonate deposits were detected both in the bark and inside the wood, which reveals deeper and more efficient absorption and retention. This reservoir of inorganic minerals provides a much more robust and long-lasting carbon storage.
The finding points to the sycamore or similar fig trees as ideal candidates for reforestation and restoration projects for degraded soils in tropical or arid climates.
Applications: reforestation, agroforestry and climate change mitigation
Integrating trees like the African fig into reforestation projects It's emerging as a revolutionary strategy to combat global warming. These trees can become vital tools in agricultural and forestry models, especially in regions vulnerable to desertification.
The studies open the door to using fruit trees with this capacity not only to capture CO2, but also to regenerate degraded soils and maintain agricultural productivity. This would allow the introduction of edible varieties into agroforestry systems, without sacrificing production. and adding ecological value.
Scientific research in the field: pioneering studies and current challenges
Research on mineralizing fig trees is still in its infancy and is in full development.An international team, comprising experts from Kenya, the US, Switzerland, and Austria, has initiated projects to quantify the total CO2 storage capacity, determine the water requirements for its development, and analyze the real potential for its use in different agricultural systems.
Most studies so far have focused on non-edible trees, so the discovery of similar properties in fruit-bearing fig trees opens up new possibilities at the level of regenerative agriculture and food security in climate risk zones.
Possibilities for the future: towards climate-smart agriculture
The potential to scale the oxalate-carbonate pathway at the agricultural and environmental levels is enormous.Identifying more species with this ability, especially in tropical and arid regions, could have direct consequences for crop resilience and global CO2 reduction.
Applying this knowledge would allow:
- Regenerate areas affected by desertification, increasing fertility and nutrient retention in the soil.
- Incorporating fruit trees into climate systems, maintaining productivity while combating climate change.
- Diversify agriculture with useful and ecological species, adapted to new environmental needs.
