Montgomery Canal

Also within

Powys County Offa's Dyke Path National Trail

Habitats

Carr, Fast flowing river and stream

Description

Description The Montgomery Canal is of special interest because it supports aquatic, emergent and marginal plant communities of exceptional richness, including a large population of the internationally rare and threatened floating water plantain Luronium natans and a several other rare and scarce water plants. An important aquatic invertebrate assemblage is also present. The Canal is situated in East Montgomeryshire and extends from Llanymynech at the border with England to Freestone Locks near Newtown. An eastern section of the Guilsfield Arm is also included within the site, as are several off-line canal nature reserves. The Canal is fed by two rivers; the River Severn enters at Pennarth near Newtown and the River Tanat enters via the Tanat feeder at Carreghoffa. The present nature of the plant and animal communities depends upon a complex interaction between factors such as water chemistry, water flow and management regimes. The aquatic plant communities of the canal are unusually species-rich. The submerged vegetation is characterised by pondweeds Potamogeton spp., including perfoliate pondweed Potamogeton perfoliatus and lesser pondweed Potamogeton pusillus and the nationally scarce grass-wrack pondweed Potamogeton compressus. Other notable aquatic plant species include autumnal water-starwort Callitriche hermaphroditica, flat-stalked pondweed Potamogeton friesii and long-stalked pondweed Potamogeton praelongus, which are rare in mid Wales. Floating plants are prominent locally, including yellow water-lily Nuphar lutea and various species of duckweed Lemna spp. The locally rare greater duckweed Spirodela polyrhiza occurs in places and floating water plantain is found along the entire length of the canal in Wales. The emergent and marginal vegetation is also diverse and well-developed. Dominant marginal species include reed sweet-grass Glyceria maxima, bullrush Typha latifolia and branched bur-reed Sparganium erectum, with a wide range of associated species, including yellow iris Iris pseudacorus and the locally rare flowering-rush Butomus umbellatus, sweet flag Acorus calamus and tubular water-dropwort Oenanthe fistulosa. The canal supports a wide range of dragonfly and damselfly species, including the nationally scarce club-tailed dragonfly Gomphus vulgatissimus as well as the white-legged damselfly Platycnemis pennipes and red-eyed damselfly Erythromma najas, which are uncommon species in Wales. Willow and alder carr have developed in association with former borrow pits alongside Wern embankment and these provide habitat for species such as kingfisher Alcedo atthis and grass snake Natrix natrix. Otters Lutra lutra frequently use the canal for feeding purposes particularly where close to major rivers. Remarks: The Montgomery Canal is owned by British Waterways. Floating water-plantain Luronium natans is listed on Schedule 8 of the Wildlife and Countryside Act 1981 (Quinquennial Review 1990) and is protected under Annexes IIb and IVb of the EC Habitats and Species Directive. The Otter Lutra lutra is listed on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended) and is protected under Annexes IIa and IVa of the EC Habitats and Species Directive.

Species mentioned

Plant communities