INNS Removal – Groundwork East

view of river with non native invasive plant species

Groundwork East is working with local volunteers to remove invasive non-native plant species (INNS) from along the banks of the River Lea. Non-native plants such as Himalayan Balsam and Snowberry may look pretty, but they are highly invasive, outcompeting native plants and reducing the biodiversity found on river banks.

What are non-native invasive plants?*

Non-native plants are those that occur outside their natural range due to direct or indirect introduction by humans. If the introduced plants persist in natural or unmanaged habitats, they are termed ‘naturalised’.

Many naturalised species do not present a problem but some that spread and outcompete native species can threaten ecosystems, habitats or native species. Only where this occurs are the plants termed invasive non-native species. These are considered to be invasive either due to lack of natural control mechanisms (such as herbivores), rapid rate of spread (by seed or vegetatively), or suppression of other species (such as allelopathy or competition for resources).

Himalayan Balsam — _{Himalyan Balsam, photo credit: Groundwork}

snowberry — _{Snowberry, photo credit: RPS Group Plc}

*_{Definitions from the RHS website}

The issues with non-native invasive plants

They change ecosystems and habitats and have non-biotic effects, such as reducing or impeding water flow leading to flooding, or changing the pH or the chemical composition of the soil, or lock up nutrients
They are expensive to eradicate. It is also very costly to restore degraded habitat, if it can be done at all

They outcompete native plants either by habitat change or by spreading so rapidly as to crowd out slower growing species, threatening the long-term survival of species
They take a long time to become invasive. Many of the plants now considered invasive have been growing in the UK for over 100 years

What we are doing and how you can help

By removing these plants, our volunteers are supporting in efforts to conserve natural species and improve riverbank habitats. Once these plants have established themselves in an area, the primary method for eradicating them is systematic pulling – removing plants by hand, including the roots, and disposing of the material. To be most effective this should be done across a whole site, removing all plants and, if the plants are flowering species, before they have set seed. This is a significant job that relies on the efforts of volunteers so we are always ready to welcome people who would like to come and learn about this important conservation task, as well as native biodiversity, and are physically able to complete tasks such as bending down to uproot ground level plants or digging out shallow root systems.

Clearing away non native invasive plant species along the river lea

If you would like to learn more about conservation efforts along the River Lea, and/or volunteer with us, please get in touch with Adam Asquith by phone on: 07702 532327 or by emailing via the button below:

email Adam

Thanks to funding and support from the Luton Lea Catchment Partnership and Affinity Water.