The Variations of Leaf δ(13)C and Its Response to Environmental Changes of Arbuscular and Ectomycorrhizal Plants Depend on Life Forms

Arbuscular mycorrhiza (AM) and ectomycorrhiza (ECM) are the two most common mycorrhizal types and are paid the most attention to, playing a vital common but differentiated function in terrestrial ecosystems. The leaf carbon isotope ratio (δ(13)C) is an important factor in understanding the relationship between plants and the environment. In this study, a new database was established on leaf δ(13)C between AM and ECM plants based on the published data set of leaf δ(13)C in China’s C(3) terrestrial plants, which involved 1163 observations. The results showed that the differences in leaf δ(13)C between AM and ECM plants related closely to life forms. Leaf δ(13)C of ECM plants was higher than that of AM plants in trees, which was mainly led by the group of evergreen trees. The responses of leaf δ(13)C to environmental changes were varied between AM and ECM plants. Among the four life forms, leaf δ(13)C of ECM plants decreased more rapidly than that of AM plants, with an increase of longitude, except for deciduous trees. In terms of the sensitivity of leaf δ(13)C to temperature changes, AM plants were higher than ECM plants in the other three life forms, although there was no significant difference in evergreen trees. For the response to water conditions, the leaf δ(13)C of ECM plants was more sensitive than that of AM plants in all life forms, except evergreen and deciduous trees. This study laid a foundation for further understanding the role of mycorrhiza in the relationship between plants and the environment.