In a previous post, we talked about how fungi play a part in carbon sequestration, and how pollution affects the fungal community in forests where it would possibly release huge amounts of carbon dioxide into the atmosphere if these organisms die.

There is an association between fungi and trees, in the way they sequester carbon dioxide, and within some forests, these relationships may be more prominent, hence better at absorbing the greenhouse gas as compared to some other forests (Averill & Bhatnagar, 2018).

A particular type of fungi that forms a relationship with tree roots, called the ectomycorrhizal fungi, increases rates of absorbing carbon dioxide (International Institute for Applied Systems Analysis, 2019; Averill et al., 2018). These fungi also slow down the process of decomposition, which means the rate of carbon dioxide being released back into the atmosphere (due to decomposition) also slows down.

However, a threat to these specific types of fungi is that they are sensitive to nitrogen pollution, which was also mentioned in a previous blog post, hence affecting the storage of carbon within forests. One of the contributing factors is the burning of fossil fuels, where nitrous oxide is being rained down onto forests. A study has found out that trees had lesser ectomycorrhizal fungi association when high levels of nitrogen are detected in the forest (Averill et al., 2018; Averill & Bhatnagar, 2018).

It is not a completely hopeless situation, as there is evidence that nitrogen pollution in the United States are decreasing, mainly due to the decrease in the burning of fossil fuels. Hence, ideally, the country should now focus on the restoration of these fungal communities within forests. However, it is easier said than done. Even if the United States start improving the situation, pollution sources from other parts of the world may still travel and reach the states, via the global circulation, which poses the same problem again (Averill et al., 2018). At least, we can see that the situation is improving, with lesser pollutant emissions now.

In conclusion, the presence of ectomycorrhizal fungi promotes more storage of atmospheric carbon dioxide, however, these communities of fungi are affected by nitrogen pollution, where their growth and survival gets threatened. If nitrogen pollutions are controlled, there may be more hope that forests can be great carbon sequestration sites.

 

References:

Averill, C., Dietze, M. C., & Bhatnagar, J. M. (2018). Continental‐scale nitrogen pollution is shifting forest mycorrhizal associations and soil carbon stocks. Global change biology, 24(10), 4544-4553.

Averill, C., & Bhatnagar, J. M. (2018, August 03). Four Things to Know about Fungi “Climate Warriors”. Retrieved November 10, 2020, from http://www.bu.edu/articles/2018/4-things-to-know-about-fungi-climate-warriors/

International Institute for Applied Systems Analysis. (2019, November 7). Plants and fungi together could slow climate change. ScienceDaily. Retrieved November 9, 2020 from www.sciencedaily.com/releases/2019/11/191107084034.htm