No abstract

Vegetation community composition and the above- and below-ground invertebrate communities are linked intrinsically, though few studies have assessed the impact of non-native plants on both these parts of the community together. We evaluated the differences in the above- (foliage- and ground-dwelling) and below-ground invertebrate communities in nine uninvaded plots and nine plots invaded by the annual invasive species Impatiens glandulifera, in the UK during 2007 and 2008. Over 139,000 invertebrates were identified into distinct taxa and categorised into functional feeding groups. The impact of I. glandulifera on the vegetation and invertebrate community composition was evaluated using multivariate statistics including principal response curves (PRC) and redundancy analysis (RDA). In the foliage-dwelling community, all functional feeding groups were less abundant in the invaded plots, and the species richness of Coleoptera and Heteroptera was significantly reduced. In the ground-dwelling community, herbivores, detritivores, and predators were all significantly less abundant in the invaded plots. In contrast, these functional groups in the below-ground community appeared to be largely unaffected, and even positively associated with the presence of I. glandulifera. Although the cover of I. glandulifera decreased in the invaded plots in the second year of the study, only the below-ground invertebrate community showed a significant response. These results indicate that the above- and below-ground invertebrate communities respond differently to the presence of I. glandulifera, and these community shifts can potentially lead to a habitat less biologically diverse than surrounding native communities; which could have negative impacts on higher trophic levels and ecosystem functioning.

Shaw RH, Tanner R, Djeddour D & Cortat G (2011). Classical biological control of Fallopia japonica in the United Kingdom – lessons for Europe. Weed Research51, 552–558. Summary The programme for the biological control of Fallopia japonica in the United Kingdom has provided some valuable insights into the practicalities of delivering a classical biological control programme against a weed in the European Union. In the absence of tailored legislation, the licensing process was complex but not prohibitive. It involved the production of a pest risk analysis (PRA; based on the EPPO template), an application through national legislation (the UK Wildlife and Countryside Act), the production of peer‐reviewed publications, expert committee consideration, further commissioned peer review and public consultations prior to final Ministerial judgement, which was granted in March 2010. Although there is room for some streamlining in the process, this approach has proved to be effective and robust and should be applicable to similar programmes in Europe. This is important, because classical biological control has considerable potential for the management of F. japonica and other weed targets throughout Europe, especially those impacting habitats where chemical use is all but impossible. The lessons learned from the knotweed biocontrol programme are discussed, and current weed biocontrol activities in Europe are briefly summarised. A classical biocontrol programme needs to deliver more than just pure science, because effective communication and negotiations in the public and political arena can provide more challenges than the traditional scientific ones.

No abstract

The rust fungus Puccinia komarovii var. glanduliferae was first identified infecting Impatiens glandulifera in its native range (western Himalayas) between 2006 and 2010. Subsequently, it was imported into quarantine in the UK for evaluation as a classical biocontrol agent. To assess the safety of the rust, plant species relevant to Europe were tested for susceptibility. To confirm the life cycle, all infective spore stages were inoculated on I. glandulifera to follow disease progression. Teliospores were primed using bleaching and low temperatures to break dormancy. Temperature and dew period experiments using urediniospores were conducted to assess the parameters required for infection. Of the 74 plant species tested, only I. balsamina, an ornamental species, was fully susceptible to urediniospore inoculum. The life cycle of the rust – an autoecious, full‐cycled species with five spore stages – was confirmed. Urediniospores were infective between 5 and 25°C, with an optimum at 15°C. A minimum of 8 h dew period was required to achieve consistent infection. Based on a pest risk assessment, the rust poses no threat to native biodiversity within EU Member States; making P. komarovii var. glanduliferae a suitable candidate as the first fungal classical biocontrol agent against an exotic weed in the region.