Ham Meadow Balsam Bash Saturday May 25th 2013

There's surely no better place to be on a sunny May Saturday than the lovely Ham Meadow by the River Thames. With its diverse mixture of wetland and terrestrial plants, an array of butterflies, birds singing, a horse munching buttercups, and a group of Environment Trust volunteers in wellies ready to do their bit by removing the invasive Himalayan and orange balsam.
This is always a popular event, and so a healthy number of volunteers set about the task of weeding out two types of balsam to allow our native species to thrive. This site has been managed in this way for a number of years now, ensuring that it does not become overrun with invasive non-native plants. We also removed a little rubbish, but there was a lot less than in previous years. Another positive feature of this area is to report that the black poplar trees (Populus nigra ssp. betulifolia), some planted by Richmond's TCV group, are doing well, and adding to the wildlife value of the site.
An interesting note about the impact of invasive species on Black poplar was found from the Biodiversity Action Plan for Greater Manchester: "Compared to the extensive and damaging effects of poplar scab, the impacts of alien species are relatively small. The prevalence of dense stands of Himalayan balsam, Japanese knotweed or rhododendron along river banks and nearby habitats may have some negative effect on potential germination of native black poplar seed. However, other factors such as lack of females [only 400 out of a population of 7000 trees in the UK] and lack of suitable habitat are more crucial."

Himalayan balsam (Impatiens glandulifera) mingles with native wetland plants, such as marsh marigold. 

Left unchecked, this area would again become dominated by Himalayan balsam. 

Chris briefs the group. 

Volunteers ensure the impact of invasive plants on Ham meadow remains minimal by weeding early in the season. 

In an area previously dominated by Himalayan balsam, a reed bed has developed. 

As well as balsam bashing, the Tower House boys helped remove half a boat washed up on the river bank.

The nearby, un-grazed meadow, is awash with buttercups.

A panorama of the group at Ham Meadow taken by Martin P.