CREATING WILDLIFE HABITATS IN A LANDSCAPE CONTEXT

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Suffolk Natural History, Vol. 40 CREATING WILDLIFE HABITATS IN A LANDSCAPE CONTEXT

PETER HOLBORN Introduction In this paper I will consider why the landscape context is so important, how new techniques of Landscape Character Assessment (LCA) can help us make land use and management decisions and finally look at some habitats at a landscape scale.

What is landscape?

The landscapes we see and experience are made up of four components: • Natural (soils, geology, flora and fauna) • Social (land use, settlement) • Perceptual (memories and associations) • Aesthetic (colour, texture, sounds, smells) We have to look at landscape as a whole; the historical geographer may be interested in field patterns, the ecologist in habitat creation but it is vitally important to understand where a landscape has evolved from and in what directions it may go. If a piecemeal approach is taken regarding land use and management decisions on individual land cover parcels the result can be a unconnected series of land uses lacking any overall character and distinctiveness. This is not to say that we should be resistant to change but it is a question of the right sort of change that respects how a landscape has evolved and conserves and enhances its landscape character.

The purpose of LCA is to look at patterns, assess character and influence change. We have been quite good at mapping and modelling the historic and biological elements of landscape but have only recently started to examine landscape character. If landscape assessment is to be of any practical value as a decision making tool then it must be able to do more than simply describe what can be seen. The assessment process must be able to provide an informed analysis of the way in which the landscape has evolved as a basis for understanding the dynamics of current and future change. The assessment of landscape character should be concerned with not just identifying distinctive patterns but understanding the reasons why the constituent physical, biological and components occur in repeating patterns.

A key component of the character based approach has been the use of digital geographical information systems (GIS) to help the storage, analysis and presentation of map based data and allow comparisons with other information across space and time.

The Character Assessment Process The first stage is desk based. For a Level 2, county or sub-regional, scale the database is structured around 8 definitive attributes grouped under physiography, ground type, land cover, settlement. Landscape Description Units (LDUs) are generated from this information using a computer software programme, and in Suffolk just over 300 LDUs have been identified (see Plate 4).

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The Character Assessment Process Source: Stephen Warnock

Amalgamate into Natural areas

Amalgamate into Character areas

Map cultural patterns and define Landscape description units

Farm type Tree cover Settlement

Cultural pattern

Cultural dimension

Veg’n & landuse

Soils

Map & define Physiographic units

Geology Relief

Landform

Natural dimension

DESK STUDY

Visual Functional integrity unity

Condition

Classification to define Landscape types

Evaluation & Decision making

Define key characteristics based on consistency and visual prominence

Use land description units as a framework for field survey

Aesthetic Distinctive qualities features

Visual dimension

FIELD SURVEY

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Each LDU has its own description code (see Plate 5); for example RCG/DFP applies to rolling lowland, on clay and chalky till giving rise to poorly drained land with gleyed soils. This would be a rural landscape with loose clusters of settlement and large farms associated with arable farming with trees in an ordered estate pattern planted at roughly the same time and including nonnative species. These LDUs are then used as a framework for the field survey stage of the process. This involves defining the key characteristics for each LDU, assessing its condition and amending the boundary as necessary according to information gathered in the field using a prescribed survey sheet.

The last stage involves amalgamating and classifying the LDUs into Landscape Character Types; for a County like Suffolk 25–35 separate Landscape Character Types could be expected.

Landscape Development and Wildlife Habitats Many of the landscape character types in Suffolk have gone through several key stages of development each contributing something to the present scene but also taking away characteristic features from the past; Roman roads, Anglo Saxon field boundaries, medieval settlement, piecemeal 19th Century parliamentary enclosures, 20th Century forests, post-1940 field amalgamation, drainage and ploughing up of grazing marshes.

There are now a rash of policies and initiatives intended to enhance the appearance of traditional landscapes and take land out of agricultural production, and this poses the question what should be done with a particular landscape. The idea of restoring landscapes like this to a particular appearance given the extent to which they have changed over the last 3–400 years is largely meaningless. We can however use LCA and an understanding of historic landscape character formation to tease out what are the distinctive continuities of landscape development and thus identify those characteristics and features which have been present over long periods of time. The idea of restoring a landscape to a particular period stage of its evolution poses difficult questions to which there are no hard and fast answers, but LCA can help us understand the processes and stages of evolution and therefore inform our decisions better.

In an agricultural county like Suffolk it may at first appear that there are not the opportunities for landscape restoration and creation on large scale as there may be on say the uplands of Wales. This is true to an extent, but already over 300 ha of heathland is being restored from coniferous plantation over a three year period under the Breckland Heathland Heritage project. Sea level rise poses us serious challenges in how to recreate those internationally important coastal habitats such as reed beds, grazing marsh and salt marsh that will be lost.

The vast majority of boundary features in Suffolk are formed by hedges, and many of these within the clayland belt of central Suffolk are ancient in origin. They tend to be species rich and form an irregular pattern of field boundaries. However there are a wide variety of hedgerow types in Suffolk depending upon their origins and management.

Post-1750 species poor hedges are often very straight and result from planned enclosures of open fields or common land. They may just contain

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hawthorn and blackthorn. Species poor hedges are not always recent in their origins though; elm dominated hedges are a characteristic feature of the Sandlings landscape and may be quite ancient. Pine belts, and rows are characteristic features of the Brecks. Holly hedges and even lilac can be found around Alderton and Trimley.

The tendency to plant mixed species rich hedges everywhere should be resisted; such hedges have never been characteristic of parts of Suffolk including much of the Brecks and the Sandlings and look out of place. Even medieval hedges may only contain 4–5 species. Attention needs to be given to conserving and restoring those boundary features that form an important element of the historic landscape.

Grasslands are one of the habitats that have been lost at the greatest rate since the mid 20th Century. In 1941 the Land Utilisation Survey of Britain recorded permanent grassland making up 25% of the total area of Suffolk; now it is less than 10%, and of this only 14% is of importance as wildlife habitat. Many wetland areas have been converted to arable, especially on silty soils rather than on peat. The former grazing marshes on along the Suffolk coast and river valleys now offer a choice of a range habitats that could be created; low intensity wet grazing, reedbed, or wet fen.

Managed wetlands are an important component of the historic landscape in their own right, displaying old, sinuous drainage patterns and every effort should be made to retain what remains. This should be in preference to their conversion to other habitats such as reed bed, which can often be created from arable land or poplar plantation as the RSPB are doing at Lakenheath.

Heathlands often have a complex history; some were created in prehistoric times and have remained clear of trees since. In others formation may have been a gradual process and even reversed, for example at the end of the Roman period when the return of woodland or wood pasture may have occurred. Some were sporadically ploughed. They were maintained by particular modes of exploitation in medieval and post medieval periods principally by grazing sheep and some times rabbits, as was the case in the Brecks. Most heaths were exploited as part of an arable economy with sheep acting as mobile muck spreaders moving between the heaths and arable land.

The Sandlings and Brecks heaths were largely destroyed in 20th Century through conversion to coniferous plantation and arable land. Chemical changes to the soil post-1950 makes heathland restoration on arable land more difficult than forest.

We know that at the time of the Domesday Survey North Suffolk was comparatively well wooded. Ancient semi-natural woodlands have survived in greater numbers and extent on the rolling clay lowlands to the south of the A14 than on the flatter plateau to the north. Tom Willamson’s work on the claylands has indicated that medieval woodlands have remained not on the flattest, wettest sites but often on the crest of valley sides. This is important in determining the siting of new woodland, as it is not just a case of in which landscape character types they are now found and previously occurred, but also the position in the landscape they should occupy. Some good work is being done with the Forestry Commission on identifying “woodland clusters”

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and suggesting where new woodland creation could give maximum wildlife benefit through reducing fragmentation. 18th Century and 19th Century designed landscapes in the form of historic parks and estates are often studied in isolation from the local landscape and just viewed as local manifestations of national trends and fashions. However they are part of the wider landscape of farms and woodlands and often display local characteristics. In the Suffolk Coast and Heaths there is a close relationship between their distribution and soil types; many great houses and parks were established on the boundary between the light soils of the coast and the claylands and also on sites affording views of the estuaries The impact of these large parks on the landscape is not just in the immediate area of the house and park. The boundary between the designed landscape and working estate land was a permeable one and designed elements often spread out far into the surrounding countryside avenues clump plantations

Conclusion I hope I have been able to give an indication of how complex some of our ancient landscapes are and the techniques we can use to improve our understanding of how they have evolved. Evidence provided by historical research and modern landscape character assessment techniques cannot be used to supply single prescriptions for the future management of the landscape. However along with other techniques for mapping and modelling the current and past distribution of wildlife habitats, they are powerful tools that can help understand the dynamics of current and future change and assist land use and management decisions.

One last plea for pragmatism though; we must be realistic and strive to create habitats that are sustainable. This means that if we want more low intensity grazing land whether wet or dry there must be a livestock industry to supply the animals and people. If we want to increase the amount of existing woodland brought into sensitive management or create new areas then there has to be a viable woodland industry in our region. Without the infrastructure for these industries to operate in we will not be creating truly sustainable landscapes. I think the biggest challenge we now face is not how or where to restore wildlife habitat but how can we manage them through low intensity agricultural and sensitive woodland management systems that are economically viable in the long term.

Peter Holborn Countryside Management Leader Suffolk County Council, and Chairman Suffolk Biodiversity Partnership Steering Group.

Environment & Transport Endeavour House Countryside & Legal Section 8 Russell Road Ipswich IP1 2BX

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Plate 4: Level 2 Landscape Character Assessment for Suffolk. Landscape Description Units are structured around 8 definitive attributes grouped under physiography, ground type, land cover, settlement (p. 12).

Plate 5: Landscape description units in the Sandlings showing description codes (p. 14).