After a damp start six of us set out to explore the wetlands of the Lune Oxbows at Melling and Arkholme.
The purpose of the trip was to monitor rare plants seen on a previous trip by the Group in 2010. These were: Blysmus compressus (Flat Sedge), Groenlandia densa (Opposite-leaved Pondweed), Ranunculus circinatus (Fan-leaved Water-crowfoot), Ranunculus peltatus (Pond Water-crowfoot), Ranunculus trichophylus (Thread-leaved Water-crowfoot), Veronica anagallis-aquatica (Blue Water-speedwell), Veronica catenata (Pink Water-speedwell), Veronica anagallis-aquatica x V. catenata = V. x lackschewitzii (Hybrid water-crowfoot), Carex riparia (Greater Pond-sedge), Carex spicata (Spiked Sedge) and Scirpus sylvaticus (Wood Club-rush).
In 2010 the spring had been dry and the pond where the Opposite-leaved Pondweed had been recorded was almost dry,heavily plodged and manured by cattle. It has not been seen since and it is likely that this once frequent and abundant species is now lost.
Two colonies of Flat-sedge were seen in 2010 but despite searching nothing was found. It is possible nutrient enrichment is to blame if this loss is confirmed. The Hybrid Water-speedwell was not seen but because of the high water levels its 2010 locality was not checked. Thread-leaved Water-crowfoot and Spiked Sedge were not seen but may still survive somewhere in the area. Greater Pond-sedge may have been seen but without inflorescences its presence was not confirmed.
Fan-leaved Water-crowfoot, Pond Water-crowfoot, Wood Club-rush, Blue Water-speedwell and Pink Water-speedwell were locally abundant. These species tolerate or favour base-rich and nutrient rich habitats. Both Flat-sedge and Opposite-leaved Pondweed require base-rich waters but do not tolerate much if any nutrient enrichment. It is believed that in recent years the R. Lune has become nutrient enriched and whilst the Lune Oxbows are rarely flooded the storms of 2015/16 inundated the area.