South Hooe: recreating wetlands and species rich grassland

South Hooe Peninsula, from the Cornwall bank

We have recently been working on a contract for a private client, funded through Natural England, undertaking a feasibility study into the restoration of species rich grassland and also freshwater wetland habitats.  The Tamar Valley AONB is helping facilitate the work and it also involves the Environment Agency.  Add in to the mix that the landowner is a former Farming and Wildlife Advisory Group advisor and you have a rather nice group of people to work for!

Avocet, copyright Christine Matthews. https://www.geograph.org.uk/profile/1777

South Hooe is on the River Tamar and is close to the upper limits used by over-wintering avocets.  The farmland has been grazed quite intensively by sheep and some of the proposed grassland has had a recent crop of turnips for winter feed, so the wildlife value is well below it’s potential.  The Environment Agency interest focuses on a large field of rushy grassland, which is currently behind an engineered flood bank.  With increasing flood defences around urban areas and rising sea levels, the Agency need to find areas to create saltmarsh as compensatory habitat.  The bonus for them is less expense maintaining a flood bank!

The semi-improved rushy grassland, photo taken from the flood bank.

So there are potential win-win scenarios for all involved, and we are working on some of the detailed mechanisms and specifications.  Matt is close to completing the work on the grassland restoration and I am now starting on some of the wetland work.  This needs to fit with the Environment Agency’s own work, which includes detailed hydrological modelling.

The main intention for the grassland is to allow fertility to gradually decline by taking an annual hay crop, followed up with light grazing.  Soil analysis has shown that while it is enriched by recent management, the phosphate and potassium levels are within acceptable limits for re-establishing species rich grassland.  So the intention is to sow the turnip field with a barley crop this year, to help bring down nutrient levels and control arable weeds.  It will then need reseeding with a wildflower and grasses mix, but the improved permanent pasture can be enriched by collecting seed from local meadows with a flora characteristic of what would be found at South Hooe.  Small areas of open ground will be created by power harrowing strips of the improved grassland, providing the right micro-climate for the collected seed to germinate.  The client has already trialled a few strips of land, with harrowing and spreading of green hay, and the initial results are promising.

Seed collection during a previous grassland creation scheme

Eighteenth century map of South Hooe (blue line follows modern flood bank).

Interestingly we have an old eighteenth century map which shows the area prior to the construction of the flood bund, which gives an idea of what might be re-created if natural processes are allowed to flow.  In our case the plan is to have the majority of the marshy grassland revert to saltmarsh but a significant area redesigned to attract wildfowl and waders.

The plan for the freshwater scrapes will involve a lower bank covering only part of the rushy grassland, and utilising water drained from the permanent grassland areas.  We expect to have a lower bank with a sluice or spill weir system that can control water levels.  The ground will be kept drier in the summer months, to enable grazing, and then be flooded in the winter to encourage avocets, other waders and wildfowl.

The Environment Agency have undertaken similar managed coastal retreat and wetland creation at Steart Point in Somerset, although on a much larger scale.  Landscape scale change and habitat creation will be essential if the country is to meet targets laid out in the twenty-five year Environment Plan.  Conservation has to be on the front foot and not just seek to limit losses or protect the nest of what we have and its good to be part of such a positive and worthwhile project.

Stephen Lees

Environment Agency visualisation of wetland