Thursday, 27 January 2011

KP (3); the rejuvenation

Freezing fog and five Great White Egrets greeted us at Ham Wall as we met to review last year’s management. Overall a very satisfactory year with 8 Bittern nests, successful breeding of Little Bittern, attempted breeding by Great White Egret and a singing Savi's Warbler.

Reedbeds under conservation management have traditionally been managed by rotational cutting, with the objective of slowing natural succession. Even on a small site, such an objective is questionable, but with a site of over 200 ha, this is not a feasible option. So Ham Wall is the focus of a larger scale ‘reedbed rejuvenation’ project. Compartments of up to 20 ha will be 'perturbed' by holding at a lower water level for a number of years and reverted to grassland by a combination of cutting, burning and grazing. After maybe five years, the ground will be re-flooded to create a shallow wetland. Reeds will slowly re-colonise but the return to early successional habitat will attract large numbers of waders and waterfowl in the early years. The land will then be allowed to return to reedbed, with higher water levels, and continue through its succession. Compartments will be 'rejuvenated' on rotation in order to maintain the early stages of reedbed.

The wet, early successional reedbed will benefit Great White Egret (as well as a range of other species) and we hope breeding will become established. The Dutch population at the main breeding location in Oostvaardersplassen reached a record high of 154 pairs in 2010 after the creation of additional feeding habitat in the late 1990s. Similar habitat will be created at Ham Wall.

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