Ectomycorrhizal (ECM) fungi is closely related to vegetation composition, soil characteristics and particular habitat processes. However, the spatial-temporal coevolution mechanism of vegetation-ECM fungi that is linked to habitat adaptation and environmental gradient is unclear.

There are also few studies examining the changes in environmental factors such as geographical location, vegetation functions, soil physical-chemical characteristics and their interactions on the composition of vegetation-ECM fungi communities.

A team of researchers, including Dr. BAI Zhen, Dr. YUAN Zuoqiang, Dr. YUAN haisheng and Dr. WANG Xugao, from the Biodiversity Group (Bacteria) and the Natural Forest Ecology Group of the Institute of Applied Ecology (IAE), Chinese Academy of Sciences investigated a 25 hm² plot in a conifer-broadleaved-mixed forest in Changbai Mountains.

To find out the key drivers affecting the composition and distribution of ECM fungi, they collected 25 environmental variables related to ECM fungi to quantify the spatial distribution, soil physical-chemical properties, vegetation functional characteristics and environmental quality gradients, and explored the underlying mechanism controlling the spatial distribution of vegetation and ECM fungi on these environmental gradients.

The study find that the spatial heterogeneity of soil physical and chemical properties is closely related to vegetation succession process and ECM fungi-related factors.

There is an obvious difference in the distribution of plant composition in the northwest-southeast direction in the 25 hm² plot, with pioneer tree species mostly existing in the north-west while the climax vegetation occurring mainly in the south-east. The abundance of ECM fungal communities is higher in the nutrient-poor eastern area than that in the water- and nutrient-rich western area. The ECM fungal diversity is the highest in the middle area of the northwest-southeast direction.

As shown in the paper, only pioneer tree species but no climax or companion tree species can be found in the northwestern area (e.g. si1), indicating that the forest succession in this area was terminated by external factors such as strong winds and diseases at some point in the past.

On the contrary, the lack of pioneer tree species in the south-east area (e.g. si5) indicates that the forest succession in the area has not been strongly disturbed. Spatial location and comprehensive score of soil physical-chemical properties are significantly negatively correlated with ECM fungal diversity and the abundance of most fungi species, clearly showing that ECM fungi can affect host vegetation growth in nutrient-poor areas through efficient nutrient supply and non-structural carbon redistribution.

The study entitled “Ectomycorrhizal fungus-associated determinants jointly reflect ecological processes in a temperature broad-leaved mixed forest” has been published in Science of The Total Environment.

The study is financially supported by the National Natural Science Foundation of China and the National Key Research and Development Program.