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RARE STONEWORTS
SLIMY-FRUITED STONEWORT AND TASSEL STONEWORT IN SUFFOLK PONDS JULIET HAWKINS
Chris Carter
Monitoring of newly restored farm ponds in several Suffolk parishes resulted in the recent discovery of two rare spring-fruiting stoneworts in 2019 (Hawkins 2019): • The Slimy-Fruited Stonewort Nitella capillaris thought to have been Extinct until re-discovered in ponds in North-East Suffolk in 2019, and • The Tassel Stonewort Tolypella intricata, with an Endangered status, recorded in ponds in North-East Suffolk in 2019 and previously known in two Suffolk sites; found scattered in various southern counties.
Nitella capillaris
Tolypella intricata
As a follow-up to two years of monitoring to find out more about the stoneworts’ persistence, I carried out further studies in 2023, funded by Natural England’s Species Recovery Project: 1. Third year monitoring the persistence of N. capillaris (Nc) and T. intricata (Ti) in the 12 ponds where one or both species were recorded (Hawkins 2023a). 2. Surveying for Nc and Ti in 53 ancient farm ponds and 14 ghost ponds (previously infilled) mostly restored in 2022, and a few more restored in 2021, to find additional sites and get a better understanding of their ecology (Hawkins 2023b). The key findings are that: • One new site for Nc, the largest yet, was discovered in a pond on Great Common in Ilketshall St Andrew 1.2km away from a very small, seasonally dry, restored ghost pond, that was known to host both species (see Fig. 1)). • In 2023 Nc and Ti were persisting abundantly in only one out of 12 ponds where they had previously been found – a ghost pond in grassland in Ilketshall St Andrew. Whilst it was not surveyed in spring 2019, following its early November 2018 restoration, it is assumed that the stoneworts fruited the year following restoration, irrespective of a cattle disturbance incident in summer 2020 and, as such, it is the only pond where both species are apparent, fruiting, in their fourth
Trans. Suffolk Nat. Soc. 59 (2023)