CONFERENCE 2003
"EAST OF EDEN"
Paul Lee
welcomed well over 250 delegates to the 13th Suffolk Naturalists' Society
Conference on 18th October. Our conference is no longer an annual event,
following Council's decision to run the event in alternate (odd) years only. If
you were not present, you can get a feel for what you missed from the following
précis.
The morning began with a
few thoughts from English Nature's Steve Preston, our chairman for the day. He
was used to English Nature having to adopt a defensive mode, so it was a change
to be able look forward to the theme for the day ,namely active habitat
creation. He reflected that whilst farmers were still under serious financial
pressure, the taxpayer was in the position of having to pay for food three times
over, first in VAT at the supermarket, second in funding agricultural
subsidies, and eventually in meeting the costs of tidying agriculture away with
a habitat recreation project.
RSPB's Land Restoration
in East Anglia was the perfect topic on which to open. Rob Macklin
explained that he was site manager of the reserve at North Warren, but would also be talking about recent
projects at Minsmere and Lakenheath, as well as future objectives. Throughout
his well-illustrated presentation, the audience was impressed at the scale of
what had been achieved, and the speed with which wildlife had succeeded in
recolonising the new habitat.
North Warren was one of four reedbed projects, aimed
not solely at the bittern, but at a wide range of plants, invertebrates and
other animals. Years without management had left 22 hectares of former reedbed
dry, and it was reverting to woodland fast; this led to the decision to
recreate habitat on a large scale. It was necessary to lower the soil bed by
30cm to put the water at an appropriate level, and this entailed felling and
burning the woodland, cutting and shifting tons of peat and spoil, and bunding off a river. Fortunately the reed
rhizomes went down a metre, so they regrew readily,
spread amazingly fast, and a complete new habitat was established in just 3
years. But at £5000 per hectare it was expensive and could not have been
achieved without funding from English Nature and the Countryside Agency. It was
good to see the otters, water voles and dragonflies that had moved in, whilst
the freshwater fish, including pike, that had appeared were providing food for
osprey on passage. Bittern had bred successfully, and it was known that some of
the chicks had moved on to Minsmere.
An even larger project had
been undertaken at Minsmere in 1997, when 40 hectares was lowered by 40cm,
converting a sycamore forest to open water and reed edge. Once again, the
photography was proof of the impressive change achieved in just 3 years. In a
separate project in 1999, a further 29 hectares of Minsmere's North Levels was
converted to open up wide ditches, incorporating some water 3m deep. Colonisation by the Norfolk Hawker dragonfly was
unexpected, but very welcome.
Tarpan ponies had
been introduced to graze the wetland; not only did they graze the willow scrub,
but they spread the reeds by trampling the rhizomes. Aerial photography of
Minsmere gave a good impression of the scale of the achievement there, as did
the counts of marsh harrier, reed warbler and water rail.
Suffolk's coastal reedbeds are under long-term
threat from rising sea levels, and this thought had been behind the RSPB's idea
of an inland reedbed site, which had now materialized at Lakenheath Fen. 300
hectares of carrot fields had been purchased with a grant from the HLF, and a
series of photographs served to impress the audience with the enormous scale of
this project, which required a 4km safety bank/drain to contain its 20km of
water channels with 12 km of banks around its inland lagoons. Here the lack of
existing reed rhizomes necessitated the planting of over 300,000 reeds into the
newly created mud banks. A system of pumps and sluices has been installed to
recirculate abstracted water. Again, the rate of natural re-colonization had
been impressive, and the success had driven the next ambitious project planned
for Cambridgeshire. This is a 30 year phased acquisition plan, aimed ultimately
at creating open water and reed grazing marsh on 700 hectares near
Needingworth.
Another scheme at Minsmere
illustrated how arable land could be used for habitat creation. Using another
HLF grant, 160 acres of farmland had been purchased for restoration to a mosaic
of heath and acid grassland, to support a range of declining birds that would
not benefit from the reedbeds. Getting the soil fertility down and acidity up
had proved to be quite a challenge, after several seasons of harvesting,
sulphur had been spread, a solution some considered radical. Heather seed and a
suitable grassland mix have now been sown, but it has taken 10 years to get to
this stage. The land management in that area will be by sheep grazing, using
Beulahs, the only breed that do well there. Surprisingly, it had not proved
easy to get the rabbit population to increase, and this was desirable if the
area was to suit stone curlews.
Lifescapes - What
habitat where? How GIS
modelling
can help, was
the title of a joint presentation introduced by 
Brenda Williamson from English
Nature’s Suffolk Coast & Heaths Lifescapes Project, and Carrie Howard who
has recently completed eighteen months working in the Suffolk Biological
Records Centre, creating computer based mapping of the area, and developing
methodology to assist in making decisions on management to benefit wildlife.
The aim had been to find ways of identifying long-term changes to the landscape
that would be environmentally and economically sustainable. The process of
displaying environmental information on maps generated from a multi-layered
geographic information system (GIS) had been subcontracted to SBRC. Typical
uses for the product might include preparing a Forest Design Plan, helping FWAG
to target agri-environment schemes, making informed decisions on land
acquisition, or selecting suitable areas for mitigation of losses due to
development.
The mapping approach began
with plotting the BAP habitats from aerial photography. Delineating the
boundaries of grazing marsh, salt marsh and heathland all required setting
limits on acceptable amounts of scrub etc. Other information sources were then
used to create "layers" showing species data, historical maps,
wildlife site designations, soil type, landscape assessments and land profile.
The output was demonstrated, and showed with brilliant clarity, information on
habitat history, particularly losses through time.
In support of BAP habitat
restoration work, the methodology was demonstrated for identifying the areas
with the greatest potential. Showing a progression of maps, which were also
available for closer scrutiny in the display hall at lunchtime, did this. The
BAP habitat, e.g. Heathland, was first displayed and then adjacent areas with
particular qualities were added, some like soil type or hydrology, others
relating to size, ownership or access and some less obvious like habitat
history, link potential or presence of BAP species. From this model, it is
possible to score individual qualities, weighting factors as appropriate, to
give a total score for each piece of land. The maps so created clearly showed
which sites might be suitable/sensible choices for habitat creation, etc.
Creating wildlife
habitats in a landscape context was the perspective outlined by Peter
Holborn, Countryside Management Leader in Suffolk County Council's
Environmental Services Division. He began with a mention of the achievements of
the first 5 years of Biodiversity Action Planning in Suffolk, and went on to give an illuminating
explanation of what landscape character is, and why it is important.
In a period of rapid
change, involving projects as large as those we had just heard about from the
RSPB, there is a need to consider the landscape angle, or run the risk of
finishing up with a mess. Mapping and computer modeling are now useful tools,
but landscape assessment is lagging somewhat. The components of landscape can
be presented as its natural elements and social elements, particularly land
use, viewed from an aesthetic standpoint or a more emotional perception (our
childhood memories are not always borne out by reality). Attempts to analyse
these components had led to a map of the "Character of England",
divided into 180 areas, but really not of much help at the local level. Suffolk's 7 Natural Areas, or
countryside character areas, made a better starting point, and it was possible
to map the historic landscape and the spoiled areas of the ancient landscape.
Recent work by the University of Reading had used the Landscape Designation Unit
(LDU) to subdivide landscape maps to show the skeleton of the countryside with
a series of codes [e.g. PCB is Plateau/Chalk/deep loam (B)]. This was
distractingly detailed, but it was vaguely reassuring to discover that Norfolk and Essex were using the same system.
A palimpsest, we learned,
is an arrangement of layers, just showing through, so that periods of
development, superimposed on one another can be used to understand the
evolution of the landscape. An attempt to restore a landscape to a particular period
is likely to be meaningless. To demonstrate fine distinctions in landscape
character, Peter showed different types of hedgerow to be found in the county
in different places, or at different times. He went on to emphasise that we can
influence change, and current DEFRA schemes for field margins will alter the
appearance of our boundary features, but that we must take care not to promote
inappropriate character in doing so. Other ongoing changes included 300
hectares of re-created heathland in forestry areas and predicted sea level
rises. The designed landscapes of the great parks had altered landscape in the
past, and with habitat creation, we were in the business of doing the same
thing again. We have a choice of habitat to convert or retain; our wet
grassland must not all be converted to reedbeds!
Some man-made changes were
reversed during a lifetime, but others could not be; soil chemistry changes
were almost irreversible. There had been a remarkable growth in woodland over
the past 20 years, and this could continue if we wanted, but where should we
best put it? Questions like this were best answered with an understanding of
the complexity of ancient landscapes; we need to evaluate the past in order to
make sound judgments on future land use. A final plea for pragmatism was made.
There must be a livestock industry, and a viable timber industry; we need to
manage sustainability.
Native Woodland - restoration and creation is the business of Steve Scott,
Conservator of the Forestry Commission for the East of England. He covered a
lot of ground from the definition of ancient woodland (continuously wooded
since 1600, when the first maps were made), on as far as the achievements of
recent years, and the challenges facing conservation and forestry. Plantations
make up 64% of the total, and a map of East Anglia shows the main forest area to be
Thetford's 19,000 hectares, with a good splattering around Suffolk, particularly in the south
west and in the Sandlings, but with thin areas towards the fens, and in the
north of the East Anglian Plain. Legal protection (6 different Acts) is in
place to protect against further losses, and a graph showed impressive woodland
growth. About 3.5% of the land was forested in 1890, with a plateau until a
period of post-war expansion cut in, and continued steadily for about 30 years.
In 1980, a steep increase began, and continued, so that land cover was doubled,
to 7% by 2000.
Steve went on to give
real-life examples of best practice at work in woodland creation. The first,
adjoining the SSSI at Long Wood is a private sector example, well known to the
SNS recorders who had an opportunity to visit twice during 2003. A piece of
former woodland, long since lost to agriculture has been chosen because it lies
adjacent to the ancient woodland SSSI, and links it to another ancient wood. A
number of interesting features, such as internal wood banks have been formed in
the embryo wood, and some dead stumps from the adjacent wood have been dragged
in to serve as habitat for deadwood invertebrates. A small amount (15%) has
been planted with young trees of local provenance, and the remainder will be
left to regenerate from seed collected from Long Wood, and by natural means.
The example from the
public sector highlighted the strategic move to adjust the balance from conifer
towards broadleaf, particularly on PAWS sites (plantations on ancient woodland
sites). 75% of conifer plantations were set out before 1975, and none have been
created since 1985; in future, all East of England sites will be progressively
restored towards semi-ancient woodland status. An aerial photograph taken by
the Luftwaffe in 1940 shows an area of high forest, and an adjacent area of
coppice with standards, in the 1990 photograph the whole forest has been
converted to conifers, by 2002 the wood has been restored to broadleaf, and
conservation work can be seen in the form of restored ponds and clearings, all
in all, amazing achievements in just 13 years.
The predicted effects of
climate change seem to suggest that beech will struggle to survive over the
next 50 years, so there will be natural changes too. Meanwhile, the "Woodland for Life" regional
strategy would play its part in achieving some difficult targets that the
Forestry commission had set for itself. Although good progress was being made
with plans to restore and create lowland mixed deciduous forest, wet woodland
was faring badly, with more being lost than had been created. Steve summarized
the future challenges as:
- Conservation. Do we want bitterns or wet
woodlands?
- Climate change.
- Losses to development.
- Funding.
- Deer. At dozens of sites, deer are eating the
guts out of ancient forests, and we need to grasp this nettle.
Visualising future
landscapes - how computers can help was the theme of Andrew Lovett, who
explained how a number of different elements of landscape visualization
technology have recently come together to allow their use in management. His
work at the University of East Anglia provided examples of totally
computer-generated images of Norfolk's Wissey catchment area to show how many layers of information
could be melded with a GIS to produce graphic images from different
perspectives. The great detail provided from multi-source inputs could be
edited to highlight or suppress relevant elements of the base data before the
addition of the projected developments and peripherals such as the weather. A
programme called Visual Nature Studio could then be used to view the terrain
from different camera positions, rendering an artist’s impression that was
flexible enough to permit input changes such as climate change predictions. A
mathematical model called CLUAM had been developed to portray land use change.
The output could be
presented to the customer by one of two interactive landscape displays, either
a large screen to allow a virtual fly-through for a Planning Committee, or a
smaller dome view that had proved a good communication device to let a couple
of observers see what the project area might look like from different
viewpoints. The hope was that such devices might improve the clarity and
honesty in the planning process. The real-time changes could transform the
answers to "what if..." questions. One remaining issue was how to
represent uncertainty in such a display; another was how realistic the image
needed to be for people to be confident with it.
Sustainable flood
management was
an absorbing presentation from Karen Thomas of the Environment Agency. She
started with an amusing series of low-tech vufoils to explain that the
Romans had been responsible for starting the concept of flood defence, and that
all of English history had been shaped by floods and our attempts to construct
coastal barriers to keep the sea at bay. The essential problem was that such
walls separated freshwater habitats from saltmarsh, mudflat and saltwater, and
that nature's storms periodically overcame the man-made barriers. Following the
1953 floods, the Royal Commission had identified the unsustainable character of
the existing approach, but that no one had paid attention, and defence building
had continued. Storms since 1953 had continued to prove that sea walls simply
did not work, and eventually the concept of Sustainable Flood Management had
taken shape.
Moving from vufoil
into Powerpoint mode, Karen then explained the detail of the managed
re-alignment of the coast that had finally been achieved at Abbot's Hall in Essex in 2002. The fundamental point is that
saltmarsh and mudflats provide the best defence against storm tides, and that a
quarter of the saltmarsh had been lost over the past 50 years. In many places,
saltmarsh and eelgrass beds had gone completely, and all as a result of
constructing the walls that were now costing a fortune to maintain. Taxpayers
were footing the bill for an attempt to protect low-grade agricultural land.
The alternative approach was to open up and allow the sea inside walls that are
going to fall down anyway. The aim would be to keep the mud back by creating
sand bunds in places, and to wash a veneer of mud over the remaining saltmarsh
to improve its quality.
The project was so big
that a partnership approach was essential, and the Essex Wildlife Trust made a
£3.5m acquisition with the assistance of WWF (UK), HLF, EN and the EA.
Hydraulic Research had been employed as consultants and the partners had
contributed funds and each had done the elements they did best. Difficulties
had been legion, and there were a mass of topics that needed serious
consideration and proper consultation. Someone always owns the land behind the
sea wall, and they have to be convinced!
The 4m contour was chosen
as the transition from crops through grazing marsh to conservation, recreating
a natural union that had not existed since the building of the sea walls.
Extensive hydrodynamics work was required to determine where to make the
breaches to avoid unwanted consequences for the fishing and oyster industry,
and the breaches were eventually made in November 2002. We were shown
photography in which clean water flows are visible coming out of the breaches
after mud has been carried in and deposited inland, as planned. Already good
botany and birdlife is evident, and 10 species of fish are using the newly
created shallows for nursery feeding. Encouragingly, these included Sea Bass
and Blackwater Herring. To date though, the water voles have declined to use
the habitat specially created for them!
The next floodtide of
"53" proportions will flood the marsh areas rather than surging up
the estuary to raise water levels inland. Future similar schemes are envisaged,
and much has been learned from the project at Abbot's Hall, particularly about
site identification, partnerships and education. Clearly, there remains a need
for coastal defences of the existing style where towns need protection, but it
is possible to move back towards sustainable coasts. To state the obvious, our
coastal strip is a finite resource.
Question Time
initially followed the coastal line of thought, with enquiries about groynes,
shingle removal, catchment planning for wetlands, and the trade-off between
habitat creation and development potential. The panel answered more general
enquiries on size and connectivity of schemes, aquifer recharge and the
economics of farming. Perhaps the most thought provoking enquiry, and this
required the use of a time-machine, was to what period in history we might best
return our landscape and nature. Individual responses varied from the
carboniferous, through Hereward the Wake, the 1930s, and simply to the time of
one's own childhood.
The full proceedings of
the conference will be published in Suffolk Natural History Vol 40 (2004).
Rob Parker
© 2003 Suffolk Naturalists' Society