Himalayan Balsam Control & Removal

Above ground Himalayan Balsam
Hollow Upright stems of red/green with tapering leaves to a point, Himalayan balsam can reach a height of 2.5 meters within a season allowing it to dominate other indigenous annuals and perennials. Himalayan balsam produces pink flowers and produce a large quantity of nectar which is one positive. However after flowering throughout summer into autumn, Himalayan Balsam will develop quite unique seed pods which will explode on contact with a number of vectors that will disturb it including animal, human and weather events. These popping seed pods can send up to 500 seeds per plant in a trajectory up to 5 meters away. The seeds can then remain viable for up to 2 years

Below Ground Himalayan Balsam
The roots system of Himalayan Balsam is minimal as it is an annual plant meaning that it will only survive one full cycle and then die, being replaced by a new plant that has grown from one of many of its seeds. It is this extensive seed quantity that creates a matting effect of growth, across large swathes of ground. The ideal conditions for Himalayan Balsam are moist soils to be able support large populations of the plant. River banks and water ways are prime locations for this. River banks rely on structural integrity to stabilize, Flora such as small trees and shrubs are perfect for this role due to strong roots systems that will last for decades if not centuries. Himalayan balsam’s ability to populate these areas quickly means out competing potential structurally strong flora. Himalayan Balsam’s small annual roots system will die off each year alongside above ground growth and can leave large swathes of river bank open to erosion.

Himalayan Balsam is classified as an invasive non-native species (INNS): http://www.nonnativespecies.org

Himalayan Balsam or Impatiens glandufoliar as it scientifically known comes under this classification for the following reasons:

• Growth rate and size- outcompetes native flora
• Different reproductive cycles and methods- explosive seed pods with large trajectory
• Resisitant to natural predators and pests – no native insects actively able control plant quantities

A key term we use to look at the effect of an invasive species such as Himalayan Balsam is biodiversity which means the variety of animal, marine and plant species throughout the world or a particular area. Biodiversity is key to balancing ecosytems with all species contributing in some way to creating a precise environment which humanity is essentially the main beneficiary. When bio diversity is compromised the adverse knock on effect is vast. The biggest negative effects on biodiversity are:

• Climate change
• Deforestation and habitat loss
• Overexploitation (overharvesting, overhunting and overfishing)
• Invasive species

How does Himalayan Balsam effect biodiversity?

In its natural environment, Himalayan balsam is not considered problematic. This is due to it being part of the correct ecosystem of the region.

• Local flora can compete with its size = reduction in size and mass
• Natural control from effective insect and herbivore species = reduction in quantity
• Natural control from localised pathogenic fungus known as rust fungus = reduction of population

In the UK, Himalayan Balsam has acute adverse impacts to biodiversity.

The presence of Himalayan balsam effects the surrounding environment greatly by what is known as habitat modification:

• Dense tall growth obscures light to smaller native plants and shrubs which produce flowers and fruit = denies food sources and pollination = reduced insect levels = reduction of small mammals, birds and amphibians’ food sources
• Annual die off leave open areas which can contribute to the erosion of river bank stability and also leave areas open to invasion of other INNS detritus from decomposing
• Himalayan Balsam chokes and clogs waterways contributing to flooding which will alter what flora and fauna (plants, insects, amphibians and mammals) can survive in the locality

Himalayan Balsam was first introduced here in the UK in 1839 around the same time as Japanese knotweed and Giant Hogweed at a time when Europe and particularly the UK were leading the way in botanical species discovery and cultivation.

Himalayan Balsam was favoured for its speed of growth and a was a cheap and exotic addition to the garden as a comparable to highly expensive orchids and the likes of the social elite. It quickly established itself out of cultivation by route of river banks and water ways.

Himalayan Balsam has definitely made its impact predominantly near the waterways of Europe, the UK and is established in important waterways in Dorset, Wiltshire, Somerset, Devon and Cornwall.

The importance of keeping rivers and waterways in good order is vital to prevent flooding with increased rainfall and erosion being localized threats and melting ice raising the sea levels globally. Habitat modification from the presence of Himalayan Balsam .see small knock on effects in biodiversity which ripple into much larger impacts in the region.

Himalayan Balsam is a schedule 9 listed species in the wildlife and countryside act of 1981 which means a legal obligation to prevent the spread in the wild of species that may have detrimental effects to ‘ecological, environmental, or socio-economic’ interests. There are 40 plants currently listed in schedule 9 of which Himalayan Balsam is just one:

http://www.ukwildlife.com/index.php/wildlife-countryside-act-1981/schedule-9/schedule-9-part-2/

The increase of redevelopment of brownfield sites sees more and more contact with non-native invasive species. Sites and land that have been left derelict or un managed are optimum for the establishment of non-native species through vectors and lapsed biosecurity. The obligations of developers are to correctly deal with any non-native species like Himalayan Balsam and can potentiatially hold up work or cease work whilst a management plan is undertaken or completed.