Himalayan balsam awareness week


The 16 – 24 May is Himalayan balsam awareness week. Run by the UK’s Inland Waterways Association, it promotes awareness and understanding of the invasive weed that’s blighting our landscape.

See some of our latest tweets on @cabi_news and latest posts on our Facebook page.

Find out more about the awareness week by visiting the Inland Waterways Association’s campaign page. It includes information on how to identify it, what to do if you come across it and how to get involved in getting rid of it.

The 22 May is also the International Day for Biological Diversity, so check out the CABI website to learn about selected projects that help protect natural systems and books from our publishing programme that you can win.

Weed biocontrol projects update


CABI weed biocontrol summaries September 2014_Page_1

Defra is funding CABI to investigate the biological control of invasive, non-native aquatic and riverside weeds. This could help protect habitats where chemical and mechanical control are impractical or prohibitively expensive; and to help meet requirements of the EU Water Framework Directive.

See the latest updates of our work.

CABI releases rust fungus to control invasive weed, Himalayan balsam


From today, not-for-profit research organization, CABI, will be releasing a rust fungus at locations in Berkshire, Cornwall and Middlesex as part of field trials to control the non-native, invasive weed Himalayan balsam (Impatiens glandulifera) using natural means.

Himalayan balsam has rapidly become one of the UK’s most widespread invasive weeds, colonizing river banks, waste land, damp woodlands, roadways and railways. The Environment Agency estimates that the weed occupies over 13% of river banks in England and Wales. It can reach over three metres in height and competes with native plants, reducing biodiversity. Large scale chemical and manual control is often not feasible and not economically viable.

Using existing measures, the Environment Agency estimates it would cost up to £300 million to eradicate Himalayan balsam from the UK.

The release of the rust fungus comes after an eight-year research programme funded primarily by Defra and the Environment Agency, with contributions from Network Rail, the Scottish Government and Westcountry Rivers Trust. During the course of the research, testing in quarantine laboratories has established that the rust fungus causes significant damage to Himalayan balsam and does not impact on native species.

Minister for natural environment, Lord de Mauley, says:
“This is a great step forwards in tackling Himalayan balsam. This invasive weed prevents our native plants from flourishing, can increase flood risk, and costs the British economy £1m per year to clean up. The work CABI has done in identifying a natural control method will help us reduce the impact of Himalayan balsam without any negative effects on native species.”

Senior Scientist at CABI, Dr Robert Tanner, says:
“The release of the rust fungus against Himalayan balsam is a result of over eight years of research evaluating the safety of its use against the target species. Over time, we should see a decline in the Himalayan balsam populations along our rivers, with native plant species recolonizing these degraded sites.”

To tackle the spread of Himalayan balsam, in 2006, CABI was commissioned to find a natural way to help control this destructive weed. The aim of CABI’s research was to find one of the many insects or fungi attacking the plant that had evolved to attack only Himalayan balsam, which could be released into the UK to control the weed while leaving indigenous species unharmed. CABI found that the rust fungus did just that.

Defra Ministers took the decision to allow CABI to release the rust fungus in July 2014. This decision followed the Food and Environment Research Agency’s (FERA) review of the scientific research and a public consultation on the proposed release of the fungus to control Himalayan balsam, which ran from May to June 2014.

New paper on the impacts of Himalayan balsam


Himalayan balsam in the UK

Himalayan balsam in the UK

This paper compares Himalayan balsam (Impatiens glandulifera) in both its native and introduced ranges.

Understanding the ecology of a plant can provide insights into whether it can become a problematic weed in the introduced range, despite it being benign in the native range.

The team used morphalogical methods to compare height, leaf area and looked at the shoot ratio, natural enemy damage and the colonization of arbuscular mycorrhizal fungi in the roots.

Consultation on the release of a rust to control Himalayan balsam


Defra are seeking your views and supporting evidence on the Pest Risk Assessment and proposal to lift the quarantine restrictions of Puccinia komarovii var. glandulifera. Defra are also seeking your views on the utilisation of this rust fungus (after rigorous safety testing) for the biocontrol of the highly invasive non-native plant, Himalayan balsam, (Impatiens glandulifera).

Please send any responses to Simon Mackown at: himalayanbalsambiocontrol@defra.gsi.gov.uk 

12 more species to avoid


Plantife’s ‘Dirty Dozen’

Himalayan balsam monoculture on the river Camel, Cornwall, UKDespite successfully campaigning for five of the worst offenders to be banned from sale in the UK, many other non-native, invasive plants are still at large. Here Plantlife outlines the 12 worst offenders (including Himalayan balsam) that are causing the most damage to the countryside and our native species.

 

Pollinator-mediated interactions between native plants and the invasive alien Himalayan balsam


A new paper has been published about pollinator-mediated interactions between native plants and the invasive alien species, Himalayan balsam. This PhD thesis explores whether the abundance of Himalayan balsam reduces native plant reproductive success.