In a bid to allow native plant life to thrive on the banks of the Northumbrian Water-owned Derwent Reservoir, volunteers from the Trust have been battling bracken and balsam.
Himalayan balsam has found its way to Britain from the Himalayan region of Asia and reproduces rapidly, spreading its seed over a wide area and suffocating native vegetation. Additionally, its attractiveness to pollinating insects threatens to decrease pollination among other, native plants.
Volunteers have been hard at work pulling the Himalayan balsam from land around Branshaw Burn, stopping its encroachment towards Derwent Reservoir, into which it feeds.
Further around the reserve at Pow Hill Heath work to crush bracken is ongoing. Bracken is a dominant plant, shading out other species and preventing their seeds from germinating. Ninety percent of the bracken plant is found underground in structures called rhizomes, these food stores and the milder, wetter winters of recent years has allowed bracken to flourish and spread fast. Bracken also harbours sheep ticks, which carry Lyme disease, and the spores it releases can be harmful to humans and cattle.
Anne Porter, from Durham Wildlife Trust, said: “Protecting the natural and native plant life from these ‘alien invaders’ is hugely important and it is vital to work with landowners, such as Northumbrian Water, to do so. We need to pull out every piece of Himalayan balsam we can find on Branshaw Burn as, if it gets into the reservoir, it will spread to all sites. This is an ongoing task, because a single plant can produce up to 800 seeds, which are viable for around 18 months and can even germinate underwater.
“With bracken, it’s a case of using quad bikes and even horses to pull rollers and crush the stems of the bracken. This damage tricks the plant into producing new leaf growth which uses up the potent subterranean energy sources in the rhizomes. Controlling bracken is good for biodiversity, as the natural flora regenerates, which is good for invertebrates, and the created open spaces provide valuable basking spots for reptiles.”
Northumbrian Water conservation advisor Mark Morris added: “Protecting the environment around our reservoirs, as well as the water itself, is a vital part of ensuring a safe and sustainable water supply, so it is great to have such brilliant volunteers, guided and led by Durham Wildlife Trust.
“Where possible, it is vital to encourage our native species to flourish, so the fightback against these other species, which threaten to overwhelm them, is an important part of our work.”