Strapwort – digging up the future

Published: January 4, 2018

strapwort-conservation-projectBlink and you’ll miss it. Corrigiola litoralis (strapwort to its friends) is a small, low-growing plant listed as Critically Endangered in the UK and legally protected under the Wildlife & Countryside Act, 1981. Slapton Ley is one of only two sites in the UK where strapwort is currently recorded, the other being Loe Pool in Cornwall.

One of the reasons for the endangered status is strapwort’s fussy nature. It has a short life cycle, has adapted to germinate in areas where water levels have recently dropped (the drawdown zone), and must grow, flower and seed before the water levels rise again in the autumn. It likes open conditions and does not do well sharing its space with tall plants that tend to crowd it out.

Disturbance of the shoreline by cattle was also thought to be crucial for exposing seed for germination in the spring. This range of special requirements means things can so easily go wrong, and led to a substantial decline from the 1980s and into the early part of this century. In fact, we got to the point where there were only seven individual plants recorded at Slapton Ley.

Alongside staff from WWCT, the reserve team at Slapton Ley decided to try a different approach to the management of the habitat at one of the three locations on the Ley’s shoreline. The results were both unexpected and exciting.

The reserve team extended the site by clearing a 20 metre section, using an excavator to re-profile the shore. The new profile was designed to increase the amount of land affected by the changing levels of the Ley and thus provide potential strapwort sites.

Over the months following the clearance we observed over two thousand new strapwort plants! How did that happen? It seems the act of re-profiling activated dormant seeds in the shingle. In some parts, the level of the shore was reduced by up to 18 inches, so the seed now on the surface had been buried for a long time. The propagation of the old seed was particularly exciting, because it has the potential to be genetically diverse. This means the site could be a source of good quality viable seed for future sites.

The challenge for the reserve team now is to capitalise on this success and maintain the numbers. So if you see a digger working away this winter then this is most likely part of this work. Thank you to Natural England for the funding and to the FSC volunteers for their efforts.

Rob Kendall
Buildings and NNR Manager
Slapton Ley Field Centre