Sandford Heath Peatland Restoration

Tender description

Sandford Heath Peatland Restoration Summary Felling and extraction of coniferous tree cover over peaty soils, infill of drainage channels using existing spoil banks and some arisings from felling works. Flailing/foraging of Mollinia tussocks, creation of pilot channel to encourage flow toward central flowpaths. See Appendix A for Site Plan (also indicates ditch location referred too in below objectives), stored under documents. Objectives Phase I Ideal Ecological Timeframe: 17th November 2025 – 28th February 2026 i. Felling area totals approximately 2.52 ha. ii. All Scots pine Pinus sylvestris and beech Fagus sylvatica to be felled; the former as non-native woodland cover on peat, and the latter as water uptake incompatible with peat restoration. iii. Birch Betula spp., willow Salix spp., oak Quercus spp., and sweet chestnut Castanea sativa also to be felled, though approx. 25 scattered and marginal veteran/future veteran trees will be retained, both in recognition of the area as a former retention area from prior felling works, and to function as ancillary and complementary habitat to the peatland restoration. iv. All trees for retention will be marked by the NE site manager prior to works. v. Stumps will be cut as low as possible but left in situ. vi. Tree lengths may be cut to length and extracted to roadside for produce where profitable. vii. Remaining arisings will be used to infill Ditch F as part of Phase III, with the remainder employed as windfall roughening features, targeted as per the map for brash infills and sparsely strewn in situ as per map to assist in diversifying the flow direction and naturalising the ground disruption, with only surplus being removed from site or burnt. No burning will take place upon the peaty soils – burning sites to be identified and agreed in conjunction with NE Reserve staff before burn begins. Phase II Ideal Ecological Timeframe: 17th November – 28th February 2026 i. Using LGP machinery flail an area (approx. 1 ha) of tussocky Molinia upstream of the peat, which will contribute to a less seasonally variable water supply to the downstream peat area; this will further support the establishment of new Sphagnum. ii. Molinia flailing should be undertaken by slow sequential cuts, a high cut to reduce height down to c. 20cm, then a low cut to c. 5cm. Where possible start in the central line of flow area then progressively outwards which will allow some reptile dispersal away from works area. iii. Following the central line of flow with machinery will assist in creating a channel to encourage the desired direction of flow. iv. Large tree stumps remain from prior felling works and will need to be avoided. Phase III Ideal Ecological Timeframe: 17th November 2025 – 31st January 2026 i. Infill Ditch F using timber and brash from felling works, retaining 5 approx. 7 m sections clear of timber and brash for infill using soil from adjacent banks during Phase IV, as per map. ii. Timber and brash fill only for majority of Ditch F: identified as area of dry to wet heath with good vegetation structure and height. The south-facing banks have high potential for reptiles so soil banks will mainly be left intact here. Phase IV Ideal Ecological Timeframe: 1st February 2026 – 31st March 2026 i. Total length of infilled ditch sections amounts to approximately 450 m. ii. Retain full flow of Ditch E beneath the confluence point and do not block, to ensure outflow is carried beneath the bridge. iii. Restore the southeastern banks of Ditch G using locally won material, ensuring the adjacent footpath remains free of inundation risk, and outflow is directed completely through Ditch E. iv. Infill 5 approx. 7 m sections of Ditch F using locally won soil from adjacent banks. v. Excavate a pilot channel south of where Ditch A turns to the southeast, as indicated on the map, to divert currently bypassing flow. Use excavated material to block the former flow. vi. Infill Ditches B, C and D using soil won from the adjacent spoil banks. vii. Water will be diverted in sequence so there are no flows along the ditches being filled: divert flow along Ditches B and D whilst C is filled and then from B and D to the central line of flow south of D, while B and then D are filled. This will also ensure sediment release is minimised. viii. Ditch F is typically dry in late summer. When infilling ditches:  Excavate any loose material and square off the section of drain channel to be infilled, to ensure that the infill material from the adjacent spoil bank will be suitably compacted. Take care to retain any bankside vegetation to use in final top dressing and reinstatement.  The spoil banks will be levelled and the drain completely infilled to ensure the mire functions correctly. If there is insufficient spoil along the whole length of the drain, focus will be on using the spoil to completely infill shorter stretches. However, spoil may also be won by creating shallow scrapes in selected areas away from the main body of the peat, to be agreed with NE Reserve staff prior to excavation.  The spoil may need to be built up to the level of the surrounding mire in manageable layers and dynamically compacted using an excavator bucket but the clay content in the spoil and the fact that none of the ditches are on the natural flow path of water means that continued flows along the old ditch lines is not likely to be significant.  Finally, dress the surface of the infilled drain with the previously rescued vegetation to encourage colonisation of flora and fauna on the restored stretch.