Together, plants and fungi could slow down climate change
A special relationship between plants and fungi, which plays an important role in carbon storage in soil, has the potential to slow down climate change. However, the amount of carbon stored in soil is decreasing as a result of human activity. This is what researchers say in a publication in Nature Communications. Nadia Soudzilovskaia from the Leiden Institute of Environmental Sciences is the lead author: ‘We urgently need to change our soil management.’
Humans have altered 50 to 75% of the terrestrial ecosystems in the world, mostly transforming them into fields and pastures. This has drastically affected the distribution of the mycorrhiza symbiosis, a special symbiosis between fungi and plants. In this relationship, the fungi provide plants with nutrients, while the plants provide the fungi with carbon. Human influence has also greatly reduced vegetation featuring a particular variety of these fungi, ectomyccrhizal fungi. This special type of plant-fungal symbiosis is crucially important to the storage of carbon in the soil.
Increased greenhouse gases
The study in Nature Communications has now shown that the loss of the plants involved in this type of relationship has reduced the ability of human-transformed ecosystems to sequester carbon in soils.
‘Carbon fixation in the soil is an important mechanism for removing carbon dioxide from the atmosphere,’ says lead author Nadia Soudzilovskaia. ‘The symbiosis between plants and fungi plays an essential role in this. By replacing natural vegetation with crops that do not host the right fungi, we have potentially massively increased atmospheric CO2.’
Combat climate change
The complex relationship between the plants and fungi and the many species involved makes it difficult to estimate the global impact of such symbioses. The study is the first to provide a global assessment of the distribution of plants and their associated fungi across the planet along with estimates of their contribution to terrestrial carbon stocks. Even if plant-fungi symbioses are lost, the study found that ecosystems including these type of vegetation still store to the order of 350 gigatons of carbon globally, compared to the just 29 gigatons stored in other types of vegetation.
Restore native vegetation
‘Our new detailed maps can help policymakers develop plans to decrease atmospheric CO2 by storing carbon in soils and plants,’ explains Soudzilovskaia. Leiden co-author Peter van Bodegom agrees: ‘Thanks to our study, we can provide a quantitative backbone to inform policy and scenario analyses to combat climate change.’
The authors advocate restoring the necessary soil fungi to native vegetation, especially in abandoned farmland and barren land, to enhance soil carbon storage. Soudilovskaia: ‘We urgently need to change our soil management. This could help alleviate anthropogenic soil carbon losses and reduce atmospheric greenhouse gases.’
Partners
The research was carried out in collaboration with multiple international research institutes, including Tartu University (Estonia), the International Institute for Applied Systems Analysis (IIASA, Austria), and Lawrence Livermore National Laboratory (USA).