We plan to transform this area over several years, felling and removing the poplar in staggered blocks and replanting the clearings with low thorn and bramble scrub the same winter. This means that the remaining poplars continue to provide shelter for feeding hirundines whilst the replacement scrub woodland matures to fill the gaps.
The replacement thorn scrub will be planted and managed to provide as much ‘edge’ habitat as possible, keeping the blocks from becoming hollow and maximising the habitat benefit for passerines such as warblers and tits. This will also increase the longevity of the scrub.
The replanted scrub will primarily consist of Hawthorn, Blackthorn, Maple and Bramble with the stums from existing willow allowed to regrow as low pollards. The overall height will be managed at no more than 12 foot. Tall enough to provide an effective wind and visual barrier but low enough to reduce the impact of perching predators and allow easy management. The poplar plantation along the Western boundary of the wet meadows was originally planted to encourage Golden orioles, Oriolus oriolus, however numbers in East Anglia have continued to decline and the habitat has not been used as hoped. The plantation and understory habitat is of limited benefit to many of the species that frequent Kingfishers Bridge, but it does offer a visual barrier between the sensitive breeding areas and the traffic using the river and fen rivers way. The trees are also an effective wind break allowing Hirundines (swallows / swifts) to continue to feed on small flying insects with even in strong prevailing winds.
Following the success of the double ditch edge at other wetland sites we are keen to include this arrangement on a range of water bodies at kingfishers Bridge including the wider ‘Rills’ on the Cam Wash SSSI, the pool in ‘The Rough’ and the Great Ditch. Work should start late summer 2016. The modified edge includes a raised bank running parallel to the shore of a ditch or other water body allowing the growth of reed. The water between the shore and this bank provides the same high quality feeding on the shallow sloping mud edge but is sheltered by the reed growth creating perfect conditions for young wader chicks which can escape into the reed quickly should they need to.
Over time the lake islands have been eroded by wave action on the lake resulting in a 30-40cm cliff around the shore. Whilst not an issue for the adult birds the vertical face is too steep for young chicks to scale leaving them vulnerable to predation. The eroded material has built up in the deeper channels between the islands limiting the availability of deeper water areas to shelter fish during freezing conditions and hampering our access to the islands by boat. Because the eroded material is underwater, when it is recovered it is too unstable to rebuild the shore without running back into the deeper areas of the lake. To combat this we have come up with a plan to remove Stable, dry soil from the centre of the islands to rebuild the shore, leaving a hole in the middle of the island which can then be filled with slubb from the lake and left to settle and stabilise.