Giant Alien Giant Hogweed (Heracleum mantegazzianum) a pernicious invasive weed: developing a sustainable strategy for alien invasive plant management in Europe.

Alien invasive plants such as Giant Hogweed (Heracleum mantegazzianum) are having a severe impact on biodiversity in Europe but no sustainable solutions are available to stop their spread and prevent future invasions. The overall objective of the project is therefore to develop an integrated management strategy that comprises effective, practicable and sustainable means of controlling an alien non-agricultural weed (H. mantegazzianum). This will provide a generic control strategy to safeguard the biodiversity of Europe from the increasingly serious threat of other alien invasives. In addition to the effective control of this species, a concept would be produced which could serve as a template by which other exotic species could be controlled or prevented from reaching the invasive phase.

The overall objective will be achieved through the following objectives:

• creating a knowledge base for H. mantegazzianum including genetics, taxonomy, biology and ecology
• modelling the invasion of the species at the local and continental scale
• searching for, and assessing potential biological control agents in the area of origin of H. mantegazzianum for potential future use in Europe, including a risk-benefit analysis, an evaluation of existing European guidelines for the importation of exotic organisms, and an implementation plan
• investigating presently applied mechanical and chemical control methods together with possible measures to reduce and prevent further dispersal of H. mantegazzianum and other alien invasive weeds
• integrating the resultant knowledge and experience to produce best practice guidelines and an integrated control strategy disseminating this knowledge to practitioners across Europe to implement effective and economic sound control measures

Major project outcomes:

• Clarification of the genotypes and subspecies in Heracleum mantegazzianum populations in Europe and a map showing the distribution of different genetic and taxonomic types of H. mantegazzianum in Europe
• Identification of ecological, biological and demographical determinants of H. mantegazzianum invasion in relation to habitat and land use characteristics
• Identification of plant communities in which H. mantegazzianum occurs and comparison of the degree of human impact on the vegetation and determination of habitat preferences of H. mantegazzianum
• Characterisation of the invasive ability of H. mantegazzianum by use of population biological parameters, germination requirements, germination rates, loss of germinability in time, dynamics of the seed bank in the field and life span
• Development of population biological models for simulating the invasive potential of H. mantegazzianum on a local scale
• Analysis of insect herbivores and pathogens associated with H. mantegazzianum
• Selection of potential control agents based on ecological data abd results of host range screening tests
• Analysis of revegetation of areas of hogweed using soil cultivation and commercially available indigenous seed mixes
• Evaluation of the presently applied mechanical and chemical control methods together with possible measures to reduce and prevent further dispersal of H. mantegazzianum and other alien species
• Development of best practice guidelines and an integrated control strategy

Further information:

Giant Alien project.