Variation in Soil Fungal Composition Associated with the Invasion of Stellera chamaejasme L. in Qinghai-Tibet Plateau Grassland.

Wei He,Haochen Wei,Lei Wang,John Scullion,Andrew Detheridge,Yahui Wei,Gareth W Griffith,Yongmei Liu

doi:10.3390/microorganisms7120587

Abstract

Stellera chamaejasme L. is the most problematic weed in China’s grasslands. Its root exudates affect co-occurring plants and thus may also affect soil fungi. Soils (0–20 cm depth) on two adjacent sites, one invaded the other uninvaded, were compared for a range of physiochemical parameters and by DNA sequencing of fungal communities. At the invaded site, relationships between S. chamaejasme abundance, soil physiochemical factors, and fungal communities were further investigated to determine whether these relationships corroborated conclusions on the basis of site differences that could be translated into functional variation. Results showed that the invaded soils had lower N, P, organic matter, fungal alpha diversity, and relative abundance of arbuscular mycorrhizal fungi (AMF), but greater abundance of pathogenic fungi. Organic matter and P were the edaphic factors most strongly linked to site differences in total fungal communities. Within the invaded site, organic matter rather than S. chamaejasme cover was closely linked to total fungal composition. However, on this site, a number of fungal species that had various ecological functions and that differentiated the two sites were related to S. chamaejasme cover. This study indicates that lower fertility soils may be more susceptible to invasion by S. chamaejasme. Although the influence of S. chamaejasme on total fungal community composition was limited, there was evidence of effects on particular fungal species. Further research is needed to determine whether these effects influence S. chamaejasme invasiveness.

Highlights

Stellera chamaejasme L. (Thymelaeaceae) is a native perennial herbaceous plant of grasslands in China
Total vegetation cover was similar on the two sites, with an average of 19.8% S. chamaejasme cover at the invaded site
S. chamaejasme was not observed in the uninvaded site (Figure 1) but sequence data showed that S. chamaejasme DNA was present in soils at seven quadrats (28%) from the uninvaded site compared to 33% of quadrats from the invaded site

Summary

Introduction

Stellera chamaejasme L. (Thymelaeaceae) is a native perennial herbaceous plant of grasslands in China. In the grasslands of northern and western China, it has become an increasingly common weed [2]. It causes a deterioration of the grazing resource due to its unpalatability to herbivores and has become the most problematic weed in China’s grasslands [3], threatening the viability of pastoral farming in affected regions. Once established, it tends to persist in part due to its avoidance by grazing animals. S. chamaejasme has deeper taproots compared to other grassland species

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