Response of Arbuscular Mycorrhizal Fungi to Global Climate Change and Their Role in Terrestrial Ecosystem C and N Cycling

Abstract

The global climate change presents a serious threat to nature and has been predicted to largely impact the life of human beings in the twenty-first century. The Intergovernmental Panel on Climate Change predicted that human-induced climate change is a major threat and also emphasized to develop global plans for mitigation and adaptation to climate change. Taking into consideration the existing feedbacks between carbon cycle and climate change, understanding whether terrestrial ecosystems will respond to elevated atmospheric carbon dioxide concentration (eCO2) or up to what extent is of utmost significance. In the global ecosystems, CO2 is largely used by plants in the process of photosynthesis (net primary production). On the other hand, microbes contribute directly, to a great extent, to net carbon exchange through decomposition and respiration and indirectly by developing symbiotic associations with plants. One of the most common symbiotic associations established between plants and fungi is known as arbuscular mycorrhizal fungi (AMF). This association facilitates the host plants for the better acquisition of water and nutrients and seems to sequester soil organic carbon. AMF could play a vital role in the global carbon cycle, as they can utilize a large proportion of the carbon fixed by the plants, deposit slow-cycling organic compounds (glomalin), and protect organic matter from microbial attack by promoting soil aggregation. In view of the importance of AM symbiosis in the terrestrial ecosystems, this chapter highlights whether the arbuscular mycorrhizal fungi contribute to soil carbon sequestration or influence soil carbon decomposition.