Climate warming may lead to considerable soil carbon losses in lower altitude forests

A recent research paper published in Soil biology and Biochemistry entitled "Translocating subtropical forest soils to a warmer region alters microbial communities and increases the decomposition of mineral-associated organic carbon" described a significant loss in soil carbon under warming in a subtropical forest.

Large amounts of soil carbon that are stored in the low altitude forests, small changes in the soil organic carbon pool in such forests may affect the global carbon balance. Previous research proposed that soil organic carbon in high latitudes or high elevations is more sensitive to climate warming. However, our knowledge of the sensitivity of the soil organic carbon in the low latitude forests response to climate warming is very limited.

Using a translocation experiment from a high-elevation site to a low-elevation site in a subtropical forest, researchers from South China Botanical Garden of the Chinese Academy of Sciences studied the responses of soil organic carbon to increases in soil temperature (ca. 1.69 ^oC).

They found that three years of warming significantly decreased the soil organic carbon content by 21.1%, and this is mainly related to the losses of mineral-associated organic carbon which reduced by an average of 15.1%.

Also, their results suggested that climate warming may increase the potential for fungal decomposition of mineral-associated organic carbon by increasing oxidase activities, leading to greater carbon losses in the subtropical forest than previously estimated.

Overall, the research showed that soil organic carbon in the low latitude is also very sensitive to climate warming, especially for the mineral-associated soil organic carbon, which is important in predicting future carbon cycling under climate change scenarios.

For further reading, please refer to: https://doi.org/10.1016/j.soilbio.2020.107707.