Long-Term Giant Hogweed Invasion Contributes to the Structural Changes of Soil Nematofauna.

Marek Renčo,Jana Jurová,Erika Gömöryová,Andrea Čerevková

doi:10.3390/plants10102103

Abstract

Heracleum mantegazzianum (giant hogweed) is the largest central European forb, naturalized or invasive in many European countries. The impacts of its colonization of native habitats on soil mesofauna groups are unfortunately obscure. This study assessed the effect of giant hogweed invasion on the communities of plants and soil nematodes in the riparian habitat. We found that invasion by H. mantegazzianum increased soil pH, decreased carbon and nitrogen content, reduced the number and coverage of the native plant species, and influenced nematode communities and their structures. Nematode species number was significantly lower in invaded than uninvaded plots, but nematode species diversity was not affected by invasion throughout the whole study. Total nematode abundance slightly increased under giant hogweed, while total nematode biomass did not differ between the invaded and uninvaded plots. The higher abundance of bacterivores and fungivores but lower number of omnivorous nematodes well represented the negative impact of giant hogweed invasion on soil food webs, supported by low values of all maturity indices or channel index. The hogweed invaded plots contained higher abundance of plant parasitic nematodes, mainly Paratylenchus microdorus. Our results thus indicate that invasion by H. mantegazzianum influences several nematode communities’ parameters while others remain unaffected by invasion.

Highlights

The invasion of non-native species is becoming one of the major threats for global biodiversity [1]
This is hindering the emergence of a unified theory of biological invasions [7], but one theory claims that a plant community becomes more susceptible to invasion whenever there is an increase in the amount of unused resources [8]
Several recent studies of our research group revealed that Heracleum mantegazzianum (Hm) botanically related invasive species H. sosnowskyi [34,35,36] or invasive species Reynoutria japonica [45] significantly influenced the structure of nematode communities and the abundance or number of species, indicating that Hm invasion of natural grasslands on river banks might alter soil nematode communities through changes in plant communities and soil properties [23,24,46]

Summary

Introduction

The invasion of non-native species is becoming one of the major threats for global biodiversity [1]. Numerous studies have shown the divergent impacts of non-native plant species on ecosystems and the contrasting effects of biotic and abiotic factors on the dynamics of non-native species This is hindering the emergence of a unified theory of biological invasions [7], but one theory claims that a plant community becomes more susceptible to invasion whenever there is an increase in the amount of unused resources [8]. This theory rests on the simple assumption that an invading species must have access to available resources (e.g., light, nutrients, and water) and that a species will enjoy greater success in invading a community if it does not encounter intense competition for these resources from the resident species. This assumption is grounded in the theory that competition intensity should be inversely correlated with the amount of unused resources [9]

Methods

Results

Discussion

Conclusion