Study Reveals Aridity and Grazing Pave Way for Invasive Weeds in Northern China

A new study led by Prof. SHAO Hua at the Xinjiang Institute of Ecology and Geography(XIEG), Chinese Academy of Sciences, has revealed how aridity and grazing jointly weaken plant community resistance, thereby facilitating the invasion of Solanum rostratum in northern China. The work was recently published in Functional Ecology.

The research team conducted a national-scale field survey spanning 3,000 km across northern China, investigating 40 representative sites to understand how biodiversity, functional traits, and phylogenetic structure of native plant communities influence invasion intensity.

They found that plant communities with higher biodiversity—especially those with greater phylogenetic diversity and functional complementarity—exhibited significantly lower invasion intensity of Solanum rostratum. High community diversity increased plant density, coverage, and biomass, and promoted resource-conservative traits, creating fewer opportunities for invaders.

However, arid climates and grazing pressures were linked to reduced biodiversity and trait complementarity, weakening these “biotic defenses” and making ecosystems more susceptible to invasion. In terms of predicting the resistance to invasion, the researchers found that the phylogenetic diversity and the Simpson index proved to be more effective than species richness.

"Our work indicates that conserving and restoring native biodiversity, with a specific emphasis on plants exhibiting resource-conservative traits, could strengthen ecosystem resistance under increasing climatic and grazing pressures," said SHI Kai, first author of the study.

This study supports Elton's biotic resistance hypothesis and highlights the crucial role of biodiversity—not just species richness, but also functional and phylogenetic structure—in resisting plant invasions.

Read the full article: https://doi.org/10.1111/1365-2435.70177

Contact

LONG Huaping

Xinjiang Institute of Ecology and Geography

E-mail: longhp@ms.xjb.ac.cn

Web: http://english.egi.cas.cn