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Invasive non-native species

Invasive non-native species control on the Ythan


In the River Ythan catchment area there are several invasive species being tackled by local volunteers and contractors.  The work is being managed by the Ythan Biodiversity Volunteers (Facebook) and Scottish Invasive Species Initiative (SISI website)  SISI’s current project is due to end in Autumn 2021, and at present there is no replacement programme.


As part of the preparation for the control project the River Ythan Trust provided Scottish Invasive Species Initiative (SISI) with the location of all invasive non-native plants in the Ythan catchment area and obtained agreements with landowners and tenants for access to parts of the riverbank affected by these species.


Working together since 2018 the Scottish Invasive Species Initiative (SISI) project, contractors and local groups including the Ythan Biodiversity Volunteers and the River Ythan Trust have been able to gain access to the riverbanks and clear the majority of the invasive plants. 


However the work needs to continue as the plants are very resilient and will return to large numbers is left untreated.    In the case of Giant Hogweed plants must be killed each year before they can produce seeds, until the seed bank in the soil is exhausted.  Giant Hogweed seeds can remain viable in the soil for 10 to 15 years.

Japanese Knotweed


Japanese Knotweed was introduced early 19th century, it is native to Japan, Taiwan and northern China.  It causes dense shade which shades out native species creating monoculture on the riverbank and erodes riverbanks.


Exists in a small number of locations throughout the river and tributaries.


More information:


Giant Hogweed


Giant Hogweed was introduced late 19th century, it is native to Caucasus mountains, Russia/Georgia.  It causes dense shade which shades out native species creating monoculture on the riverbank and erodes riverbanks.  It also contains dangerous sap in all parts of the plant that can cause severe skin irritation and even hospitalisation.  Giant Hogweed is the most serious invasive non-native (INN) plant problem in the Ythan catchment.


More information:

Himalayan Balsam


Himalayan Balsam was introduced mid 19th century, it is native to west and central Himalayans.  It causes dense shade which shades out native species creating monoculture on the riverbank and erodes riverbanks.


Himalayan Balsam has been found near Newburgh at the Foveran Burn in the past.


More information:



How to report an invasive non-native species sighting


If you see an invasive non-native species of plant or animal you can report it to the Scottish Invasive Species Initiative (SISI) and/or the North East Scotland Biological Records Centre (NESBReC). 


Report your sighting: