The mechanisms of biodiversity maintenance has been a hot topic in ecology for decades. Fungi and insect herbivores contribute to the diversity of plants in grasslands, which has been frequently reported. However, evidence about their driving roles on forest herb diversity is not enough.

Research scientist WANG Xugao and Dr. JIA Shihong from the Natural Forest Ecology Group of the Institute of Applied Ecology (IAE) of the Chinese Academy of Sciences (CAS) recently published their new findings on forest herb diversity maintenance. 

The researchers conducted a field manipulation experiment in a temperate forest in northeastern China and examined the effects of fungi and insect herbivores on herb diversity by using fungicides and insecticide.

In this way, the researchers found that fungicides decreased herb diversity by 5%, and that the negative effect was weaker in the studied plots where there were higher number of neighbouring tree species. Though insecticide was able to reduce herb diversity as well, but only in plots dominated by deciduous trees.

They found that fungicides and insecticide affected herb diversity depending on the defensive traits of herb species (e.g., leaf thickness), and only did the herbs with thinner leaves or non-clonal traits significantly decrease their species diversity when the plants were sprayed with fungicides and insecticide. 

The study indicates that fungi and herbivorous insects play a non-negligible role in maintaining species diversity of understory herbs in the temperate forest.

The study entitled "The effects of natural enemies on herb diversity in a temperate forest depend on species traits and neighbouring tree composition" has been published in Journal of Ecology. This study was funded by the National Natural Science Foundation of China and the (Class B) Strategic Priority Research Program of CAS.