History of grazing marshes
Historically, the Broads comprised an extensive estuary system.
Grassland would have been present in its lower reaches and close to the river channels, mudflats and salt marshes. Reed-beds and fen would have thrived in the rivers’ upper reaches, tributaries and flood plain fringes where freshwater conditions predominated.
This historical pattern of vegetation is broadly reflected in the various soil types found in the Broads today, with clay and silt soils in the grazing marsh areas previously under the influence of the brackish river system and peat soils supporting fen, reed-bed and wet woodland in the upper reaches where freshwater conditions prevailed.
Grazing marsh timeline
Marsh reclamation started. Sea levels at that time were about a metre below present. Sheep grazing predominated.
By this time many areas had been reclaimed through improvement to existing flood banks, driven by increases in sea level rise and a wish to increase agricultural production. There was a move towards cattle production in preference to sheep.
Most of the grazing marshes of today had been drained by the 18th century and they were still grazed predominantly by cattle. Transient flooding occurred frequently due to the inefficiency of land drainage pumps.
Enclosure of land took place during the early part of this century, and this paid for improvements to the land drainage infrastructure. From this time onwards, drainage became ever more efficient and flooding became rare.
Further major improvements to the drainage infrastructure were achieved through technological developments, driven by the wish to maximise agricultural production. In 1913, the first diesel pump was installed. During the 1930s the 18 Internal Drainage Boards within the Broads came into existence. During the late 1930s and 1940s highly efficient electrical pumps became widespread.
In March 2005 the government introduced a new Environmental Stewardship scheme, to replace most other agri-environment schemes, including the Environmentally Sensitive Area scheme (ESA).
Wildlife response to grazing marsh management
Throughout the whole and continuing history of the Broads grazing marshes, there is no doubt that they represent an outstanding wildlife resource, in particular for wetland birds, aquatic plants and invertebrates within the extensive dyke systems.
However, it is clear from studying and comparing historical records of numbers and variety of species of birds and plants on these grazing marshes with those of the present day that, with each stage of agricultural intensification, there has been a corresponding decline in the value of the grazing marshes to wildlife.
In spite of the positive changes to the management of the grazing marshes achieved through the ESA scheme there has not, as yet, been a wide-scale improvement in wildlife. Indeed recent studies indicate that the decline is continuing.
It is increasingly considered that other factors such as diffuse pollution also have a significant influence on the health of the whole Broads wetland ecosystem. In the coming years, it is anticipated that measures introduced under the Water Framework Directive will contribute to the recovery of the grazing marshes.