Barton Broad

8/7/2019 Barton Broad

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Loss of habitats: wetlands

Case study: The Norfolk Broads



What is a wetland?

� A very productive ecosystem- second to

the TRF

� An ecosystem that functions viainputs,outputs,energy and nutrient flows

and feedback loops.

� Temperate wetlands- lowland wet grass

and upland and lowland peat bogs



Traditional Broadland scene at

Howe Hill� Reed swamp

� Drained by rivers and

dykes, drainage

channels

� Grazing

� Traditional windmill

� Carr woodland



Barton Broad in the 1890s



Traditional management

supports a diverse ecosystem� Summer grazing or hay cut for winter fodder

� Winter seasonal flooding too boggy to graze

� Traditional habitats fostered for lapwings,curlews,snipeand some rarer breeds.

� Provides winter feeding ground for migrant wildfowl-e.g.widgeon,teal,shoveler, pintail,Bewick and whooper swans.

� Ditches and dykes form barriers to the movement of grazing cattle and provide drinking water.

� Grazing cattle disturb insects especially at drinking sitesso the insects are easy food for birds ie sustain the foodchains.

� Waders, summer visitors and breeding birds need insectrich environments to feed their young.



Barton and Howe Hill



The impact from intensive

farming� Drained land for more intensive agriculture (arable)reduces species diversity as habitats are lost

� Hay cutting replaced by silage production and moreintensive grazing

� Alters the functioning of the system as the variety of niches disappear

� Ditches and dykes lost

� Range of plants decreases

� Number and variety of insects declines

� Loss of food for carnivores ( birds and mammals)



Application of fertilisers

� The rapid rise in the use of fertilisers

� Intensification so that more fertilisers needed to maintainyields

� Nitrates very soluble so large amounts dissolve in soilwater

� More efficient drainage so water infiltrating into the soilenters the ditches, rivers and broads more rapidly.

� Water in ditches and broads becomes sediment and

nutrient rich� Eutrophication leads to murky water, thick mud and

reduced biodiversity



The impact from a changing

economy� Diversification into tourism

� Increasing pollution from sewage and

slurry� Rapid rise in greenhouse gases and

resulting global warming. Key concerns

are rising sea levels, the threat of flooding

and the incursion of salt water, and

warmer summers which may dry out some

wetlands.



Barton Broad Clearwater

Project 2000� A significant area, the second largestBroad

� A National Nature Reserve, owned byNorfolkWildlife Trust

� Part of the Ant Broads and Marshes SSSI

� A Ramsar Site ( An international

designation from the Ramsar ConventiononWetlands)

� An EU Special Protection area for birds.



Reeds on the edge of Barton Broad

� The reedswamp is a natural

cushion (rond) between water

and grazing

� Protects the banks from

erosion� Important habitat for wildlife,

spawning ground for fish and

site for dragonflies.

� Has aesthetic value

� Was part of the rural economy� Is susceptible to high

concentrations of nitrates.

� Is an indicator of clear water



Reeds at Barton



The management of Reeds

� Restoring the aquatic environment will support

reed growth and provide ecological niches for

fish and dragonflies

� Scrub clearance is necessary in some places

� A market is being found for reeds for thatching.

The British Reed Growers Association is

supported by the Broads Authority for goodcommercial and conservation practice



Harvesting the marsh grazing

� The Wetlands harvest project has attracted finance from

a range of sources for a harvesting machine to cut the

marsh grazing to cope with the boggy environment and

pioneer a drying technique to pellet the marsh hay for

fuel or fodder so that drainage is not necessary for

farmers to make some profit

� Grazing trials are being monitored to establish the level

of grazing that is sustainable



Carr woodlandCarr woodland alder, sallow and birch trees, guelder rose, buckthorn dog rose and

brambles in the shrub layer.

Ferns, mosses, liverworts and lichens are found in the damp shady undergrowth



Sedge along the bankside



Vegetation of fen carr



Carr management

� Some has been cleared to create more open fen ± reeds

� Mature carr needs little management and is part of thecharacteristic landscape

� Younger carr is being managed by English Nature andlocal landowners to maintain species diversity

� There is economic potential from coppicing alder for wooden piling to replace steel piling along the Bure.

� Coppicing can improve bank access and is favoured by

sailors so is appropriate for some areas



The Barton scheme

Clearwater 2000� An integrated project that recognises the

role of agriculture and tourism in the local

economy but is recreating a rich wetland

environment which attracts a wide range

of plants, insects, birds and mammals.

� A sustainable approach



Barton Broad today



Measures taken before 2000 that

compliment the project

� Controlling nitrogen fertilisers. This area is

in a NSZ nitrogen sensitive zone where

the application of fertilisers is strictly

controlled.

� Agro environmental policy

� New sewage treatment plants installed

� Dredging to remove phosphate rich sludge

from the broads



Agro environmental policy- hedge

planting to protect soils from

erosion and encourage wildlife



Autumn and spring ploughing



Mud pumping and silt lagoons

Clearly, one way to make a big impact (even if not a permanent one) on the phosphorus levelsin the water of the broad was to get rid of the

thick bed of nutrient-rich mud, lying on thebottom. In Nov 1995 the huge suction dredgingoperation began and contractors removed300,000 cubic metres of phosphate-rich mud(the equivalent of 160 Olympic-sized swimmingpools) A network of settlement lagoons werecreated on 22 hectares of nearby fields to holdthe silt that was removed.



Mud pumping, phosphorous

removal at sewage plant and silt

lagoons



Biomanipulation to clear the water

and restore an ecological balance

� Understanding thefood chains meansthat daphnia have

been encouraged tofeed on the excessivealgae

� Fish are trapped andrestricted so that theydo not eat too manydaphnia until thewater is cleared



Tourism and recreation



Completing your case study

Find out more

� WideWorld

September 2000

� www.broadlands-

authority.gov.uk

� Light and Dark in A

level geography folder

Tasks

� Summarise the

stages of restoration

undertaken at BartonBroad

Barton Broad

Documents

Transcript of Barton Broad