Abstract: Mycorrhiza is defined as a mutualistic symbiosis between plants and fungi localized in roots or root_like structures in which energy moves primarily from plants to fungi and inorganic resources move from fungi to plants. Since most land plants in the world belong to families that are commonly mycorrhizal, mycorrhizal fungi may play important roles in nature. Findings of many researches, especially those of recent studies, are helpful in understanding the role of mycorrhizal fungi in the structure and functioning of ecosystems. In this paper, the following aspects of mycorrhizal fungi research were introduced: 1) As an important part of ecosystems, mycorrhizal fungi consume a great deal of photosynthate and are parts of food chains between autotrophic plants and fungivores; 2) Mycorrhizal fungi have a great effect on the biogeochemical cycling through taking part in the enzymatic decomposition of litter, promoting the absorption of inorganic ions or compounds, accelerating the weathering of miners, and contributing to the process of biological nitrogen fixation; 3) Mycorrhizal fungi affect the structure and functioning of the ecosystems in different ways. They have an interaction with microbes in the soil and thus may have an influence on the composition of soil microbes. They influence the inter-or intra-specific interactions of plants through having beneficial effects on host plants or connecting different plants with mycorrhizal networks. Mycorrhizal fungi play an important role in the maintenance of biodiversity and stability of plant communities, and they can also act as an indicator, participator and promoter of succession of plant communities; 4) The magnitude and species composition of mycorrhizal fungi may indicate the changes of an ecosystem, and mycorrhizal fungi can also be used in the conservation of natural ecosystems or restoration of damaged or desert ecosystems. The focuses of recent mycorrhizal fungi researches and a brief perspective was also discussed in this paper.

Key words: Mycorrhiza, Mycorrhizal fungi, Functioning, Ecosystems