1.General



Chapter-1

Definitions

1. Avenue : A wide road or pathway lined with trees on either side.

2. Buffer : The use of landscape to curtail view, sound or dust with plants or earth berms, wall, or any such element.

3. Climber (Creeper/Vine) : A non-supporting plant, woody or herbaceous, which clings to a wall, trellis or other structures as it grows upward.

4. Columnar : A slender, upright plant form.

5. Egress : A way out, or exit.

6. Elevation : A contour line or notation of relative altitude, useful in plotting existing or proposed feature.

7. Exotic : A plant that is not native to the area in which it is planted.

8. Fencing : A barrier of plant or construction material used to set off the boundary of an area and to restrict visual or physical passage in or out of it.

9. Foliage : The collective leaves of a plant or plants.

10. Geo-textile : Any permeable textile (natural or synthetic) used with foundation, soil, rock, earth or any other geotechnical engineering-related material as an integral part of a human made project, structure or system.

11. Grade : The slope or lay of the land as indicated by a related series of elevations.

11a Natural Grade : Grade consisting of contours of unmodified natural land form.

11b Finished Grade : Grade accomplished after landscape features are installed and completed as shown on plan as proposed contours.

12. Gradient : The degree of slope of a pipe invert or road or land surface. The gradient is a measure of the slope height as related to its base. The slope is expressed in terms of percentage or ratio.

13. Grading : The cutting and/or filling of earth to establish smooth finish contours for a landscape construction project. Grading facilitates good drainage and sculpts land to suit the intent of landscape design

14. Grasses : Plants that characteristically have joint stems, sheaths and narrow blades (leaves).

15. Groundcover : The planting material that forms a carpet of low height; these low-growing plants are usually installed as the final part of landscape construction.

16. Hard Landscape : Civil work component of landscape architecture such as pavement, walkways, roads, retaining walls, sculpture, street amenities, fountains and other built environment.                        

17. Hardy Plant : Plants that can withstand harsh temperature variations, pollution, dust, extreme soil conditions, and minimal water requirements and the likes. These plants have ability to remain dormant in such conditions and survive.

18. Hedge : Number of shrubs or trees (often similar species) planted closely together in a line. A hedge may be pruned to shape or allowed to grow to assume its natural shape.

19. Herb : An annual plant with a non-woody or fleshy structure. Certain herbs are highly useful for cooking or of high medicinal value.

20. Ingress : A way in, or entrance.

21. Invert : The low inside point of a pipe, culvert, or channel.

22. Kerb : A concrete or stone edging along a pathway or road often constructed with a channel to guide the flow of storm water and thereby serving dual purpose.

23. Mound : A small hill or bank of earth, developed as a characteristic feature in landscape.

24. Native : A plant indigenous to a particular locale.

25. Planting : Planting is the operation of transferring young plant from nursery to their permanent place in landscape.

26. Screen : A vegetative or constructed hedge or fence used to block wind, undesirable views, noise, glare and the like, as part of in landscape design; also known as ‘screen planting’ and ‘buffer plantation’.

27. Sediment : The product of erosion processes; the solid material, both mineral and organic, that is in suspension, is being transported or has been moved from its site of origin by air, water, gravity or ice.

28. Shrub : A woody plant of low to medium height, deciduous or evergreen, generally having many stem.

29. Soft Landscaping : The natural elements in landscape design, such as plant materials and the soil itself.

30. Spot Elevation : In surveying and contour layout, an existing or proposed elevation noted as a dot on the plan.

31. Street/Outdoor Furniture : Items of furnishing in outdoor landscape.

32. Swale : A linear wide and shallow depression used to temporarily store, route or filter runoff. A swale may be grassed or lined.

33. Topsoil : The uppermost layer of the soil.

34 Transplanting : Moving a plant from its place of origin to another location. Transplanting is the process of bodily lifting of mature and large plants from their position to a new position

35. Tree : A woody plant, generally taller than 2.00 m, with a well-distinguished trunk or trunks below the leaf crown.

35a. Deciduous Tree : Tree that sheds all its leaves in autumn or in dry season.

35b. Evergreen Tree : Tree that remains green for most part of the year and sheds leaves slowly throughout the year.

36. Tree Grate : A metal grille, installed at the base of a tree otherwise surrounded by pavement, that allows the free passage of air, water, and nutrients to the tree root, but does not interfere with the foot traffic.

37. Tree/Plant Guard : The protection constructed around a tree to deter vandalism and help to prevent damage. It could be made of metal, bamboo or concrete or the like.

38. GRIHA (Green Rating for Integrated Habitat Assessment) : The National Rating System will evaluate the environmental performance of a building holistically over its entire life cycle, thereby providing a definitive standard for what constitutes a ‘green building’. The rating system based on accepted energy and environmental principles, will seek to strike a balance between established practices and emerging concepts both national and international.

(Source : GRIHA Manual Volume 1)

39. Green building: Buildings have major environmental impacts during their life. Resources such as ground cover, forests, water, and energy are dwindling to give way to buildings. Resource-intensive materials provide structure to a building and landscaping adds beauty to it, in turn using up water and pesticides to maintain it.

(Source : GRIHA Manual Volume 1)

40. Green Building Rating System : A green building rating system is an evaluation tool that measures environmental performance of a building through its life cycle. It usually comprises of a set of criteria covering various parameters related to design, construction and operation of a green building.

(Source : GRIHA Manual Volume 1)

Chapter – 2

Planting Design Consideration

(Source : NBC)

The following criteria shall be considered in planting design :

1. Plant Material

2. Soil conditions

3. Availability and quality of water

4. Availability of sunlight

5. Quality of air

6. Maintenance

7. Functional Aspects of Design with Plants

8. Planting for Shelter and Soil Conservation

9. Air Pollution Control by Plants

1Plant Material

The major sets of factors that influence the choice of plant material are related to the characteristics, both botanical and physical of plant material and the context in which the plant material is to be used. The inter-relationship of these sets of factors is the basis for developing a sound approach to the process of designing with plants.

Physical and Botanical Characteristics of Plant Material

The information on plant material should be available in a systematic format to include definition, significance and design implications of the following aspects :

a. Nomenclature (botanical and trade-name);

b. Origin, family and natural habitat;

c. Growth characteristic and form as a function of habitat;

d. Physical characteristics, for example bark, texture, foliage, etc.

e. Propagation and maintenance; and

f. Use in landscape design.

Vegetation Types (Evergreen and deciduous) : Some examples of the functional implications of using evergreen and deciduous plant material for specific situations are :

a. Evergreen trees for :

i. Places requiring shade throughout the year,

ii. Strong visual screening

iii. Part of windbreak or shelter planting, and

iv. Areas where leaf lifter is to be discouraged.

b. Deciduous trees for :

i. Greater visual variety,

ii. Partial visual barrier,

iii. Areas where under-planting is to be encouraged (for example grass), 

iv. Emphasis on branching and flowering pattern, and

v. Areas where shade is not required throughout the year.

Growth Rate and Age of Vegetation : Growth rate is directly related to the life span of tree and slower growing trees have a life span extending to hundreds of years. The fast growing trees to the exclusion of slower growing varieties is not recommended. Landscapes are developed to sustain future generations; slow growing long lived native trees shall be emphatically included in all major planting schemes.

Growth Habits of Various Kinds of Vegetation and Their Form : The overall physical form of a plant is usually the result of the foliage density and branching pattern. It may also be expressed as the proportionate relations between height and canopy spread. The later is direct expression of growth habit. The following classification into basic types may be useful (Also Refer : Chapter on List of Trees)

a) Trees of fastigited or columnar habit – Examples of trees of this type are : Casurina esquisitifolia (beet wood) Grevilea robusta (Silver Oak) Polyathia logifolia (Ashok) Populus species (Poplar) Though the branching pattern of each is different, the overall shape is similar

b) Tall trees with canopy – Examples of trees of this type are : Dalbergia sissoo (Sheesham) Tamarindus indica (Imli) Terminalia arjuna (Arjun) The canopy share does not fit into any specific geometrical category

c) Trees of spreading habit – Example of threes of this type are : Delonix regia (Gulmohar) Lagerstroemia flosreginae (pride of India) Pithecolobium saman (Rain Tree) Though these trees vary greatly in size, their basic form is similar

d) Trees of weeping habit – Examples of trees of this type are : Callistemon lanceolatus (Bottle brush) Salix babylonica (Weeping willow / Peking willow).

The above classification is helpful in choosing various combinations of the above types to achieve desired function and visual objectives.

2. Soil Conditions

Physical as well as chemical properties of the available soil are important. These may or may not be amenable to change; they would therefore affect the choice of plant material considerably. Physical properties include consideration of light (for example sandy) and heavy (for example clayey) soils, and their structure. Chemical properties pertain to the presence or absence of nutrients and salts; soil, alkalinity or acidity. A effective planting schemes.

3. Availability and Quality of Water

The water requirement may be derived by data of humidity and rainfall of plants natural habitat. The water table of the area where the plantation is to be done has a crucial bearing on the design with plants as well as a financial implication for reduced maintenance if planted appropriately.

4. Availability of Sunlight

The growth rate of plants are directly related to sunlight availability; such as plants that require (a) full sunlight, (b) partial sunlight, (c) predominantly shade, and (d) complete shade.

5. Quality of Air

Growth may be affected by chemical pollutants such as sulphur dioxide or physical pollution such as dust. Certain plants have the ability to withstand pollution, such plants are imperative for industrial areas, roads, highways, etc.

6. Maintenance

The success of a designed landscape depends upon the growth of vegetation over an extended period of time; therefore maintenance of landscape is also a design component.

7. Functional Aspects of Design with Plants

a. Improve existing environmental conditions with respect to soil, drainage, microclimate, air pollution;

b. Create a designed physical environment through the organization of open space; and

c. Interpret and express the contemporary understanding of the man-nature relationship, that is, design with plants on an ecological rather than horticulture basis.

* Shrubs

– The functions are similar to those o trees. Shrubs may be used together with trees to reinforce the functions, for example, noise barrier, shelter belts, enclosures, etc. Other forms in which shrubs may be used are:

a. Hedges : These require regular maintenance

b. Shrubbery : Here plants are allowed to retain their natural shape; they therefore require little maintenance.

Shrubs provide barrier, which may either be visual or physical (hedges). Barriers may be required in a range of situations, for example they may be only for defining space, or they may be required for security and have to be, therefore, necessarily impenetrable.

* Groundcover

– Groundcover plants are those which naturally grow to a very low height. Some of the uses for which they may be used are:

a. Stabilization soil on steep slopes such as embankments.

b. As a low maintenance substitute for grass (where the surface is not to be used).

c. For providing variety in surface treatment.

d. Contrast with paving materials, for example to soften rigid lines of paving.

e. As a subtle means of demarcating space, as for example, in places where tall plants would be visually intrusive.

f. In combination with other plants to provide contrast or harmony in form.

Climbers : Certain climbers because of their spreading habits may also be used as ground cover(for example Asparagus spp.) Climbers are useful for shading exposed walls from direct sunlight. They may also be used for stabilizing soil on embankments (for example, ficus stipulate, Ipomea biloba). On sites where a high degree of security makes fencing necessary, climbers and spreading plants like Bougainvillea species, may be trained on boundary wall.

8. Planting for Shelter and Soil Conservation

The use of vegetation for controlling wind is widely recognized as an effective way of conserving soil and reducing erosion by wind. Vegetation may therefore be used for modifying the microclimate, by obstructing, guiding, deflecting or filtering wind current.

Vegetation areas designed to fulfill these general functions are usually classified as windbreakers and shelterbelts. Windbreaker is grown protective planting around gardens and orchards. Windbreakers generally consist of single or double row of trees. Shelterbelt provides an extensive barrier of trees with several rows of trees. Plant species are chosen with particular regard to their physical and growth characteristics, and their effectiveness in achieving the desired results.

Function : Windbreakers and shelterbelts fulfill essential microclimatic functions in rural and urban environments. Benefits accruing from plantation of shelter planting may be as follows :

a. Reduction in wind velocity resulting in the arrest of movements of soil particles.

b. Prevention of soil erosion.

c. Modification of micro- climate; moderation of change in air temperature.

d. Protection of crops from being blown by high winds.

e. Reduction in evaporation of soil moisture. Increase in soil moisture content varies from 3 percent to 7.8 percent Water loss due to evaporation is lessened.

f. Increase in soil moisture due to greater dew fall in sheltered areas has been found to be 200 percent higher than on exposed ground; heaviest dew fall is over a distance of 2 to 3 times the height of the shelterbelt.

g. Beneficial effect on growth of plants that are affected by high winds.

h. The zone of influence of shelterbelt on crop yield extends to a distance of 20 times the height of the belt, with the maximum effect being observed 10 times the height of the tree belt, on the leeward side.

Wind Erosion : Some of the basic functions of windbreaks and shelterbelts in arid and semi- arid areas are to conserve soil and reduce erosion by wind. The latter is a natural phenomenon in and lands having very little rainfall (125 mm- 250 mm) and in areas adjoining a river, lake or sea. Wind erosion is a serious problem in areas where the ground is virtually bare and devoid of vegetation.

Techniques for control of wind erosion : The principal method of reducing surface velocity of wind, upon which depends the abrasive and transportation capacity of wind, is by vegetation measures.

a. Porosity is important in the effectiveness of shelterbelt and proper selection of tree species is necessary. Porosity near ground level is desirable.

b. Effectiveness of shelter planting depends more on height and permeability than on width. The width influences the general microclimate but above a certain minimum width, it does not affect greater reduction in wind velocity.

Protection obtained varies in relation to height (H) of shelterbelts as given below :

Distance Wind Reduced by (in percent)
H 90
5H 75
2H 50
10H 20

This indicates that it is better to have several windbreaks 5H to 6H apart rather than large forest stands with wide open spaces in between.

9. Species suitable for wind breaks are :

a. For Dry and Arid Regions

i. Acacia auriculiformis (Australian Blackwood)

ii. Ailanthus excelsa (Maharukh)

iii. Albizia lebbeck (Siris)

iv. Azadirachta indica (Neem)

v. Casuarina equisetifolia (Beef- wood)

vi. Dalbergia sissoo (Sheesham)

vii. Eugenia Jambolana (Jamun)

viii. Grevillea robusta (Silver oak)

ix. Peltophorum ferrugineum (Cooper pod)

x. Tamarindus indica (Imli)

xi. Pongamia glabra (Indian beech)

xii. Tamarix articulate (Tamarisk)

b. For Coastal Area

a. Anacardium occidentale (Cashew)

b. Ailanthus malabarica (Alston)

c. Cassuarina equisetifolia (Beef-wood)

d. Pongamia glabra (India beech)

e. Sesbania aculeate (Sesban)

f. Thevetia Peruviana (Yellow oleander)

g. Thespesia populnea (Indian Tulip)

h. Vitex negundo (Sephali)

1. Air Pollution Control by Plants

Air pollution may be caused by areas or point sources such as cities, industrial areas, factories or by linear sources such as highways. Vegetation buffers can minimize the build-up of pollution levels in urban areas, by acting as pollution sinks.

Effect of Plants : Plant leaves function as efficient gas exchange systems. Their internal structure allows rapid diffusion of water-soluble gases. These characteristics allow the plant to respire and photosynthesize, and they can also remove pollution from the air. Some of the beneficial results of plantations may be:

a. They are good absorbers of sulphur dioxide.

b. Parks with trees have an SO2 level lower than city streets.

c. Roadside hedges can reduce traffic generated air borne lead, on leeward side.

d. Heavy roadside planting in the form of shelterbelts can result in a reduction in airborne lead.

e. Complete dust interception can be achieved by a 30m belt of trees. Even a single row of trees may bring about 25% reduction in airborne particulate.

Chapter – 3

Role of Vegetation in Landscape Design

(P.S.Sodhi, M. Arch. (Landscape), Architect, CPWD)

With the advent of technology, the man is becoming isolated from nature day by day. The rapid urbanisation has resulted in diminishing the landscape features. The early culture of India is full of plant love, intimately concerned with the day to day life. With the increase in population and large scale Urban Development has taken a heavy toll on the green areas and has alienated the people from nature.

The trees play a vital role in a community’s scenic beauty, the character of the local landscape and the overall quality of the environment. Despite their benefits, trees are disappearing faster than we think.

Just imagine what our streets and neighbourhoods would be like without trees! Benefits of Planting and Protecting Trees

Environmental Value : Trees provide a variety of environmental values, including screening of unpleasant odours, absorption of noise and reduction of pollution and temperatures in the cities as described below :

–Air Quality : Trees are an efficient and cost-effective way for a community to improve its air quality and reduce pollution. A mature tree absorbs between 120-240 pounds per year of small particles and gases, like carbon dioxide, which are released into the air by automobiles and industries. In addition, a single tree produces nearly three-quarters of the oxygen required for a person; and a canopy of trees in an urban environment can slash smog levels up to 6%.

– Water Quality : Trees help anchor soil and reduce storm water runoff, saving the high costs of drainage ditches, storm sewers, and other “engineered solutions” to storm water management. A street lined with 32’ tall trees can reduce runoff by almost 327 gallons, allowing cities to install smaller and less expensive water management systems. Reducing runoff also decreases topsoil erosion and the amount of silt and other pollutants washed into streams, rivers and lakes.

Lower Heating and Cooling Costs : Trees have demonstrated the ability to reduce heating and cooling costs and counteract the “heat island” effect in urban environments. Urban areas with little vegetation can experience temperatures of up to seven degrees higher than those with tree cover. This translates into significantly higher energy costs to cool buildings. Properly planted trees can cut heating and cooling costs by as much as 12 % and reduce overall power demand.

Reduced Noise Pollution : Noise pollution is an often overlooked problem. Excessive or unwanted sound has negative physical and psychological effects. Noise can come from many sources, especially roads and highways. Trees can play an important role in deadening unwanted noise. Sound waves are absorbed by a tree’s leaves, branches, and twigs. Studies suggest that belts of trees 100’ wide and 45’ long can cut highway noise to half.

Ecological Value : Plants provide significant values to all sectors of natural environment in cities. The loss of vegetation cover adversely affects the soil, Air & Water balance.

– One of the major values of plants is improving of urban soil conditions. Urban soils are often buried beneath the sidewalks, streets and buildings. However, a significant portion in many urban areas remain exposed to environmental conditions which helps in improving urban soil conditions by building the Soil with roof system, by checking the loss of surface particles, by increasing the organic material contents in soil and retaining the water for longer period, to increase the ground water table. Soil benefits from trees, as their far-reaching roots hold the soil in place, preventing erosion. Trees improve soil quality as their leaf litter makes perfect compost. Some trees, for example acacias, have bacteria living in their roots. The bacteria convert nitrogen from the air into nitrates, which the tree can use to grow and reproduce, whilst the soil is also enriched.

– Plants also help to control the extreme fluctuation in temperature and reduction of pollution level in urban atmosphere. Plants have a useful effect upon the climate e.g. a comparison of the temperature difference in summer, between a planted area of urban landscape and built-up central area is likely to be 2-3°C lower with a 5% increase in relative humidity.

– During the process of photosynthesis all green plants take in carbon dioxide and give off oxygen. Primitive plants were responsible for converting the poisonous atmosphere of early Earth into an oxygen-rich atmosphere that supports animal life. Trees help to maintain low levels of carbon dioxide, thereby reducing the greenhouse effect which threatens to make the Earth uncomfortably warm.

–  Trees provide nest sites for birds. The leafy branches make good hiding places and are difficult for most predators to reach - even non-breeding birds roost in trees at night.

Health Value : There is mounting evidence that stress and noise have an impact on our physical and psychological health. Trees and vegetation can affect our mood and help relieve stress.

Economic Value : Trees are a major economic asset to a community, building a positive community image which is a key factor in attracting residents, businesses, and visitors alike. The attractively tree-lined public areas are more desirable than those areas without trees. The landscaped areas enjoy higher occupancy and rental/lease rates than identical properties that lack landscaping.

Shelter : The shade of trees is welcomed by man and beast alike, providing essential shelter in the hottest climates. Trees are often used as windbreaks to shelter sensitive crops.

Aesthetic Value : Trees provide a variety of aesthetic values and accentuate the architectural design of buildings. For all their values to which a price tag can be attached, trees have one more contribution to make: their beauty and variety of form. Some species are tall and thin, others flat-topped and spreading, leaves come in every shape and size, flowers and fruits are frequently decorative. These qualities make trees ideal for beautifying gardens, cities, and even industrial estates.

Planting is much more than a cosmetic treatment to be applied to in different or insensitive architecture and engineering etc. It plays a major role in integrating structure into environment, providing a setting and reducing their visual intrusions within the functional requirement of any single area. Plants are growing, ever changing, interacting organism and plant communities are in a constan state of flux. Plants, whether trees, shrubs, climbers, groundcovers have to be placed at suitable location so that the desired purpose is served.

The efficient and successful choice of plants should be made on the basis of their design characteristics :

1. Functional & Structural Characteristics : Plants in combination and individually, create space beneath, between & sometimes within the bulk of their canopies. Plants create landscape structure, which both defines spaces and serves the required function.

Trees, in the city are living building material used to establish spatial boundaries. They create spatial rhythms to heighten the experience of moving through the outdoor spaces, its ability to shelter, screen or shade, density of roof growth which will determine its ability to bind the soil and protect against erosion. Plants also provide a fitting environment for human activities while avoiding damage to ecology of the landscape.

2. Visual & Other Sensory : Plants offer an enormous wealth of aesthetic characteristics, the appearance of their laves, twigs, bark, flower & fruit, the fragrance of flower and aromatic foliage, the physical texture of bark & leaves even the sound of laves when stirred by the wind or beaten by the rain.

3. Plant Growth Habit & Cultural Requirement : There is enormous diversity of size, habit foliage & other characteristics among the range of species; that helps to determine the habitat & ecological niche. In the first place, planting design can help us make the best use of our environment. Secondly, it helps to restore the balance between people, nature and in some extent to the wild life and finally it offers many opportunities for enjoyment of aesthetic delights.

4. Plants and Their Uses : Plants are positive design elements in any environment and they can enhance the environment, if used with proper understanding

5. Trees (basic planting) : This relates to the contemporary requirement in landscape design for mass planting of large groups, woodlands, which with the topography or land form, produce the large scale spatial arrangement of the landscape. The species selected for this group should be hardy, vigorous in growth, indigenous for ecological reasons and exotics which have become established as part of local scene.

e.g.- Acacia auriculiformis, Lagerstroemia flos reginae (pride of india), Pterospermum acerifolium (kanak champa), Alstonia scholaris, Putranjiva roxburghii (jalpitri), Azardirachata indica (neem), Dalbergia sissoo (sheesham) etc.

Trees (special effects) : Trees in this section should include those sufficiently individualistic, spectacular or strong in character to occupy the isolated positions, either because of these qualities or because they do not mix easily in visual sense with other trees.

e.g.- Ficus bengalensis (banyan tree), Cassia fistula (amaltas), Bombax malabaricum (silk cotton tree), Cassia nodosa (pink javanica), Jacaranda mimosaefolia (neeli gulmohar). Chrosia speciosa, Mimusops elengi (mulsari) Callistemon lanceolatus (bottle brush) etc.

Trees (barriers) : Barriers formed with plants are needed in landscape for screening the unpleasant views, for dividing up the landscape into spaces, for providing shelter from wind, for protection against pollution, for defining boundaries and for assisting in the creation of beautiful landscape.

e.g.- Casuarina equisetifolia, Grevllea robusta (silver oak), Ficus benjamina, Polyalthia longifolia (ashok), Putranjiva roxburghii, Schleichera trijuga (kusum), Golden bamboo etc.

Shrubs (basic planting) : The use of shrubs in the mass as a basic constituent of the planting of Landscapes. It should have the qualities of hardiness, vigorous growth with a greater emphasis on evergreen plants.

e.g.- varieties of Acalypha, Bougainvillea, Cassia biflora, Cassia alata, Duranta, Ficus panda, Euphorbia, Thevetia, Taberneamontana (chandni), Palms such as areca, china, phoenix, rhapis etc.

Shrubs (special effects) : Similar principles of selection apply to this as for trees (special effects), but at the same time it should be noted down that a number of shrubs planted together can produce special effects specially at the time of flowering.

e.g. – Caesalpinia pulcherrima (peacock flower), Calliandra haematocephala, Poinsettia, Mussaenda, Justicia, Ixora, Bamboo-buddha valley, Franciscea latifolia (yesterday, today and tomorrow), etc.

Shrubs (barriers) : Impenetrability is essential unless the barrier is for visual purpose, thus the twigs or thorns are considered as an advantage. Other things to consider are the ability of the plant to accept pruning, either to control growth or to produce topiary effects.

e.g. – Bouganvillea, Duranta plumieri, Duranta plumieri varigata, Duranta goldeana, Murraya etc.

Shrubs (edging) : To outline the flower beds or other kinds of plants and to create line effects.

e.g. – Duranta goldeana etc.

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