This document provides an overview of the syllabus for a lecture on silviculture for B.Sc. Forestry students. It lists key textbooks on silviculture and forest management. It then covers various topics that will be discussed in the lecture, including principles of silviculture, forest classification systems, tree growth and morphology, environmental factors influencing forests, forest succession, regeneration strategies, tending operations, and forest mensuration. Diagrams are provided illustrating forest types in India and symbols used for regeneration status.
3. 3
Principles and practices of Silviculture by L.S. Khanna.**
A textbook of silviculture by A.P. Dwivedi.
An Insight into Indian Forestry- P. Sivakumar**
Forest Management by Ram Parkash*
Forest Mensuration and Biometry by A.N. Chaturvedi and L.S. Khanna*
Theory and Practice of Silvicultural Systems by L.S. Khanna*
Textbook of Agroforestry by B.S. Chundawat and S.K. Gautam*
An Introduction to Agroforestry by P.K. Ramachandra Nair
http://apps.worldagroforestry.org/Units/Library/Books/PDFs/32_An_introduction_to_a
groforestry.pdf?n=161
Applied Forest Tree Improvement by Bruce Zobel and John Taibert*
A handbook of forest utilization by T. Mehta
Handbook of Forestry (part 1 & 2) By L.S. Khanna and A.N. Chaturvedi
Indian Forestry (A Breakthrough Approach to Forest Service) by K. Manikandan and
S. Prabhu.
Important Books
4. STRATEGIES
Throughout study the syllabus
Prepare small notes for each section
Identify the section which needs more focus
Always prefer textbooks to class notes
Repeated revisions is very must
Group discussion is very helpful
4
5. SILVICULTURE
Concept of silviculture and Silvics –Definition; objectives
Forestry- types; basis of classification
Understanding of different stages of tree growth and development: Seedling,
sapling, pole and tree
Crown shape: Phoenix, Cocos and Borassus have crowns of large leaves at
the tops of cylindrical unbranched stems; Mangifera indica,Azadirachta
indica, Tamarindus indica, Madhuca indica, etc., are spherical in shape;
Albizzia stipulata the crown is broad and flat topped; Abies pindrow crown is
more or less cylindrical.
Autumn tint: leaves undergo a striking change in colour before falling from
the tree. For eg; the leaves of Lannea coromandelica turn yellow; Anogeissus
latifolia dark red or bronze; Sapium sebiferum beautiful red and orange.
5
6. Leaf shedding: Evergreen and Deciduous
*Santalum album becomes deciduous or evergreen according to the habit of its
host plant
Deciduous – Acacia catechu, Adina cordifolia, Ailanthus excelsa, Bombax ceiba,
Garuga pinnata, Holoptelia integrifolia, Lannea coromandelica, Melia
azaderach, Schleichera oleosa, Terminalia tomentosa.
Evergreen – Abies pindrow, Cedrus deodara, Cupressus torulosa, Hopea
parviflora, Mallotus philippinensis, Mangifera indica, Michelia champaca, Picea
smithiana, Pinus wallichiana, Pterospermum acerifolium
Buttress: Out growths formed usually vertically above the lateral roots and
thus connect the base of the stem with roots. Eg: Acrocarpus fraxinifolius,
Bombax ceiba, Pterocarpus dalbergiodes, Terminalia myriocarpa, etc
6
7. Fluting : Irregular involutions and swellings on the bole just above the basal
swell. Eg; Teak
Tap roots: direct prolongation of the radicle of the embryo
Adventitious roots: roots produced from parts of the plants other than the radicle
or its subdivision
Rhizome of bamboo is adventitious root
Prop-roots – Ficus bengalensis
Stilt roots-Rhizophora
Pneumatophore: Heretiera, Bruguiera, mangrove species
Mycorrhiza: ectotrophic, endotrophic and ectendotrophic
Ectotrophic: Basidiomycetes
Endotrophic: Phycomycetes
Occurrence – Mycorrhiza is found in Pinus, Picea, Abies, Cedrus, Cupressus,
Taxus, Populus, Aurocaria, Salix, Podocarpus and Eucalyptus, etc.
7
8. Lignotubers: underground swellings; modified stems ; food storage and helps
in regeneration; active when tree is injured, cut or burnt. For eg, Eucalyptus.
Root Nodules-Rhizobium; commonest being Leguminosae family such as
Dalbergia, Bauhinia, Acacia, Albizzia, Erythrina, Tephrosia, Crotolaria,
Indigofera and Leucaena. They are, however, not found in Cassia tora.
Flowering of tree species:
Monoecious – Pinus, Abies pindrow
Dioecious – Salix, Mallotus, Taxus, Diospyros, Cedrus deodara, Pistacia
Polygamous – Sterculia, Garuga, Rhus
Pollination:
By wind (Anemophily) – Conifers, Betula, Alnus, Juglans
By birds (Zoophily) – Bombax, Butea, Erythrina, Anthocephalus, Oroxylum (the
last two are pollinated by bats).
By insects (Entomophily) – Sal, Teak, Sissoo
8
9. Flowering of Bamboo: Gregarious; Sporadic; Annual
Examples of annual flowering: Arundinaria wightiana, Bambusa lineata,
Ochlandra stridula, etc.
Species Interval in Months
Ailanthus excelsa 2
Tectona grandis 3
Acacia catechu 4-5
Dalbergia sissoo 6-7
Cedrus deodara 12-13
Pinus roxburghii 24-26
Interval between Pollination of Flowers and Ripening of Seed
9
10. Forest: area set aside for the production of timber and other forest produce,
or maintained under woody vegetation for certain indirect benefits which it
provides, e.g., climatic or protective
Stand: an aggregation of trees occupying a specific area sufficiently uniform
in composition (species), age arrangement and condition to be
distinguishable from the forest on adjoining areas
The unit of silviculture is a Stand.
Classification of Forests: Basis
Even aged forest: Differences up to 25% of the rotation age may be allowed
in cases where a stand is not harvested for 100 years or more.
Pure forest : forest composed of almost entirely of one species, usually to
the extent of not less than 80%.
10
11. Crown differentiation:
Dominant trees: upper most leaf canopy and have their leading shoots free;
predominants and codominants (5/6 of the predominants)
Dominated: leading shoots are not overtopped by neighboring trees; height is
about ¾ of the tallest trees
Suppressed: Trees which reach only about ½ to 5/8 of the height of predominants
Factors of locality:
Radiation (light, heat and temperature) Moisture and Wind
11
12. FROST: chilling of air below the freezing point. Depending on the mode of
occurrence, it is classified into:
i) Radiation frost: frost occurring on nights with a clear sky, produced by loss
of heat by radiation
ii) Pool frost: accumulation to a considerable depth of heavy cold air flowing
down into natural depressions from adjoining areas. Example: Dehra Dun valley
iii) Advective frost: frost produced by cold air brought from elsewhere
Frost pocket, frost hole or frost locality which is defined as an area in which
frosts are more frequent and more intense than in the district generally. Frost
free season which is defined as the period between the last injurious frost in
spring and the first injurious frost in the autumn.
12
14. Frost hardy – Acacia catechu, Hardwickia binata, Madhuca indica, Toona
ciliata, Pinus roxburghii
Moderately frost-hardy – Adina cordiforlia, Bombax ceiba, Dalbergia
latifolia, Gmelina arborea
Frost tender – Acacia arabica, Azadirachta indica, Tectona grandis,
Terminalia arjuna
Snow influences the distribution of deodar, fir and spruce and their best
forests are found in places of heavy snowfall.
In India southern aspects are warmer than northern slopes.
Drought hardy species: Acacia arabia, Hardwickia binata, Bomabax ceiba,
Syzigium cumini, Xizyphus jujuba, etc.
Moderately drought hardy: Acacia catechu, Dalbergia sissoo, Gmelina
arborea, etc.
Drought sensitive: Tectona grandis, Shorea robusta, Terminalia arjuna, etc.
14
15. Name of zone Total annual
rainfall (mm)
Nature of vegetation
Wet 2500 or more Wet evergreen
Intermediate or
moist
<2500 to >900
Wet semi-evergreen
Moist deciduous
Dry deciduous
Dry <900
Dry deciduous forest of poor
quality
Desert and semi-desert thorn and
scrub forest
Forest types on the basis of rainfall received (mm) in India
15
16. Influence of parent rock on species distribution:
Pinus roxburghii (chir pine) in quartzite rock; Pinus wallichiana (blue
pine) in Mica schist; Cedrus deodara in alluvium soil; Cupressus torulosa
(lime stone) and Tectona grandis (lime rich); Shorea robusta in quartz
and black cotton soil; Xylia xylocarpa and Cleistanthus collinus in laterite
soil.
Soil: classification; profile
Humus: Mor (unmixed with mineral soil; high acidity; poor nutrient
status; raw humus) and Mull (mixed with mineral soil; low acidity; high
nutrient status; mild humus).
Sal grow best in the soil pH between 4.5 and 5.5 whereas teak grows well
in the pH range of 6.5 to 7.5.
While Neem, Karanj, Arjun etc grow well in the alkaline soils.
16
17. Biotic factors: parasites; climbers; obnoxious weeds; animals includes
insects
Plant succession: definition; basis of classification; causes of succession
Monoclimax (or climatic climax theory) is developed by Federic Clements
Polyclimax theory was proposed by Tansley (1939)
Classification of climax: Climatic climax examples (important)-Sal forest in
North Indian Tropical Moist Deciduous Forest; Edaphic climax-eg, Wet
bamboo brakes in the south tropical wet evergreen forest.
Pre-climax: definition; eg;-chir pine on the ridges of subtropical broad
leaved forest, patches of Anogeissus latifolia in sal forest
Sub-climax (biotic climax): chir pine forest in the hills where Quercus
incana is climatic forest; sal, teak, deodar in moist locality areas.
17
18. Forest types of India: Basis of classification (physiognomy; structure; function;
floristic, dynamics; habitat; physiography)
System of classification: Botanical (Vegetation) ;Braun-Blanquet, Beard,
Forsberg and Webb used this system of classification.
Climatic (Climate); Schimper (temperature), Mayr (temperature along with
altitude and latitude; Koppen (temperature and rainfall), Thornthwaite
(temperature efficiency) and Shanbhag (thermodynamic principles);Bioclimate:
Seth and Khan, Paterson
Ecosystem (vegetation and climate): Champion and Seth, Swain, Gaussen
Forest types of India: According to Champion and Seth (1935): 5 major
groups; 16 groups and further divided in sub groups, types
Teak and sal forest group need to be focused more: for example-sal (group 3:
tropical moist deciduous forest) teak (group 5: Tropical dry deciduous forest-
5A/C1-dry teak bearing forest)
18
22. Tending Operations
Definition of tending:
Difference between tending and cultural operation: Scope of cultural
operation is more than tending operation
Stages of cleaning: herbs, shrubs; inferior species; dead and malformed of
desirable species; singling of coppice shots of favorable species; climber
cutting
Thinning: objectives
Tree classification: symbol denoted
Kinds of thinning: definition, stage at which the thinning is carried out (for
eg, mechanical thinning is carried out at the early stage where crown
differentiation does not take place); formula used in mechanical thinning
(glover, Warren, etc)
22
23. Ordinary thinning: Low thinning, German thinning, thinning from below
Grades of ordinary thinning: Light (A), moderate (B); heavy (C)-
generally used in yield table preparation ; very heavy (D and E)
Application of ordinary thinning: light demander species, etc
Crown thinning: French thinning, high thinning, thinning from above
Grades of crown thinning: Light and heavy
Applicable of crown thinning: moderately shade tolerant
Free thinning: concentrated on elites or alpha stems; proposed by Heck
Maximum thinning: Proposed by Gehrhardt; modification of free
thinning
Crown thinning, selection thinning, improvement felling: applicable in
mixed irregular crops
23
24. Forest mensuration is that branch of forestry which deals with the
determination of dimensions (e.g., diameter, height, volume, etc.), form,
age and increment of single trees, stands or whole woods, either standing or
after felling.
Volume is the most important measurement from the point of view of forest
management.
Objectives of Forest Mensuration
Scope of Forest Mensuration
Forest mensuration aims at reasonable or relative accuracy, i.e., maximum
accuracy which is profitable and possible to obtain in practice.
Reasons for adopting relative accuracy in forest mensuration.
FOREST MENSURATION
24
25. Systems of measurement
a) British system of F.P.S. System and
b) French or metric system or C.G.S. system
Prior to the passage of The Standards of Weights and Measures Act, 1956, the
British system of F.P.S. system was used in forestry in India. Metric system or
C.G.S. system which was introduced in October 1962, is now a legal necessity.
12 inches = 1 foot
3 feet = 1 yard
66 feet or 22 yards = 1 chain = 100 links
10 chains or 220 yards = 1 furlong
8 furlongs or 1760 yards = 1 mile
25
30. OBJECT OF DIAMETER AND GIRTH MEASUREMENT
The main object of measurement of individual trees is to estimate the quantity
of timber, firewood or any other forest produce
Volume of a tree is dependent on diameter or girth at breast height, total tree or
bole height and form factor which is a measure of form or shape of the tree.
Breast height (B.H. or b.h.) is defined as almost universally adopted standard
height for measuring girth, diameters and basal area of standing trees. In India,
Burma, America, Union of South Africa, Malaya and some other former British
Colonies it is taken as 1.37 m (4 ft 6 in) above ground level.
While Europe, United Kingdom and most other countries of the Commonwealth
have it as 1.3 m (4 ft 3 in) which has also been recommended by F.A.O. as
standard for international adherence.
Reasons for accepting breast height as the standard height for diameter or
girth measurement.
30
32. Relationship of Diameter (D) and circumference Girth(G) of a circle: G=𝝅D, or
D=G/ 𝝅
The circumference or girth(G) at breast height (GBH) can be measured with an
ordinary tape, and then DBH can be calculated from the above formula.
Bark thickness may be determined with an instrument known as Bark Gauge. If
“t” represents bark thickness, then diameter-under-bark (dub) and girth-under-
bark (gub) can be obtained from the measured values of diameter-over–bark
(dob) and girth-over-bark (gob) with the help of the following formula:
dub = dob – 2t
gub = gob-2𝛑t
The proportion between error involved in use of calliper and tape is 21:1.
The use of calliper is more susceptible to error than the use of tape and the
errors in case of the former are also greater in magnitude
32
33. Metric system British system
2 cm class for trees usually
attaining maturity under 30 cm
d.b.h.
1 inch class for trees usually
attaining maturity under 12” inch
d.b.h.
5 cm class for trees usually
attaining maturity at 30 - 50 cm
d.b.h.
2 inch class for trees usually
attaining maturity at 12-20 inch
d.b.h.
10 cm class for trees usually
attaining maturity at 50 cm d.b.h.
and above
4 inch class for trees usually
attaining maturity at 20 inch d.b.h.
and above
DIAMETER AND GIRTH CLASSES
33
34. Diameter classes in
metric system
Colour Diameter classes
in British system
0 - 20 cm Blank 0 - 8 inch
20 - 30 cm Green 8 -12 inch
30 - 40 cm Red 12 -16 in
40 - 50 cm Yellow 16 - 20 in
50 - 60 cm Black 20 -24 in
60 - 70 cm White 24 - 28 in
70 - 80 cm and above Blue 28 -32 inch and
above
A scheme of colours diameter class
34
35. Measurement of height
Height is generally considered as an index of fertility and with knowledge of
age it gives a reliable measure of the site quality of a locality.
Total height of a standing tree is the straight line distance from the tip of the
leading shoot (or from the highest point of the crown where thee is no leader)
to the ground level, usually measured on slopes from the uphill side of the tree.
Bole height . It is the distance between ground level and crown point. The
crown point is the position of the first crown forming living or dead branch.
Bole height expresses the height or length of the clear main stem of a tree.
Commercial bole height is the height of bole that is usually fit for utilization
as timber.
Height of standard timber bole is the height of the bole from the ground
level up to the point where average diameter over bark is 20 cm.
35
36. Stump height : It is the height of the top of the stump above ground. It gives the height of
the tree stem which is left attached to the ground after felling.
Crown length : It is the vertical measurement of the crown of a tree from the tip to the
point half way between the lowest green branches forming green crown all round and the
lowest green branch on the bole.
Crown height : It is the height of the crown as measured vertically from the ground level
to the point half way between the lowest green branch and the green branches forming
green crown all round.
Methods of measurement employ simple principles of Geometry principles of similar
triangles or Trigonometry and assume that trees are perpendicular to the ground.
Instruments used for measuring tree heights are collectively known as hypsometers.
Various instruments based on these above mentioned principles. For instance, Christen’
’s
hypsometer, Smythies’hypsometer are based on principles of similar traingles; Brandis
hypsometer, Relaskop, Tele Relaskop, Barr and Stroud dendrometer and Blume-Leiss
hypsometer are based on trigonometry principle.
36
37. TREE STEM FORM
Form is defined as the rate of taper of a log or stem.
Taper is the decrease in diameter of a stem of a tree or of a log from base
upwards.
The taper varies not only with species, age, site and crop density but also in
the different parts of the same tree.
37
38. Fig: The formula for a paraboloid and the frustum of a paraboloid.
38
39. METZGER’S THEORY OF GIRDER THEORY
The stem of the tree is built up in such a way as, with the minimum of material, to
offer uniformly the greatest resistance to the stresses to which it is subjected.
According to this logic, the tree stem must have the shape of a cubic paraboloid
The form of a tree can be studied in one of the following ways:
a) By comparison of standard form ratios
b) By classification of form on the basis of form ratios and
c) By compilation of taper tables
Form factor: Artificial form factor (breast height form factor); Absolute form factor;
Normal (or true) form factor
Absolute form factor and normal form factor are no longer used. Unless
otherwise stated, form factor in India implies artificial form factor with basal area
calculated at 1.37 m above ground level.
F=V/Sh
Where F is the form factor; V is the tree volume in cubic units; S is the basal area of
breast height in area units and; h is the height of the tree in linear units
39
40. FORM HEIGHT
Form height is defined as the product of form factor and total height of tree
Fh=V/S
FORM QUOTIENT
An Austrian forester A. Schiffel postulated that taper depends on what he called as
form quotient (F.Q. or f.q.) and defined it as the ratio between the mid-diameter and
the d.b.h.
FQ=mid diameter/dbh
Tor Jonson, a Sweedish forester, used Normal form quotient: the ratio of mid-
diameter
or mid girth of a tree to its diameter or girth at breast height.
Absolute form quotient: ratio of diameter or girth of a stem at one half its height
above the breast height to the diameter or girth at breast height.
Form class
Form point ratio: the point in the crown as which wind pressure is estimated to be
centered.
40
42. Calculation of volume by quarter girth
formula
(Hoppus’ rule in Britian)
Volume of log=(g/4)2 x l
where g is the girth of the log at the middle and
l is the length of the log
The volume by quarter girth method and the full circular method shows that
the former gives only 78.5 per cent of the true volume
Commercial volume
Standard stem timber
Standard stem timber
Xylometric method
Specific gravity method
42
43. Volume table
Classification of volume tables: Volume tables can be classified in three
ways, viz., (i) according to the number of variables on which they are based,
(ii) according to the scope of their application and (iii) according to the kind
of outturn given by them
Preparation of volume table:
Table of basic averages:
TARIFF TABLES: The term tariff table or tariff has been applied in France,
Switzerland and Germany to volume tables giving volume in terms of breast
height girth alone, without differentiation of height class.
43
45. Forest Management
Definition
Scope
India’s first Forest Policy was enunciated in 1894, which laid down public
benefit as the sole objective of management of public forests; giving
preference to agriculture over forestry
National Forest Policy 1952: First National forest policy after Independence
The Policy also suggested keeping a minimum of one third of the country’s
total land areas under forests, with 60% in the Himalayas and other hilly tracts
liable to erosion and 20% in the Plains.
National Commission on Agriculture (N.C.A) 1976
The Parliament, by the 42nd Amendment to the Constitution in 1976, brought
forests and wildlife on the concurrent list in 7th schedule.
45
46. Forest organization
(i) Geographical & Climatic (or Ecological)
(ii) Functional
(iii) Legal (or Statutory)
(iv) Territorial
(v) Administrative (or Organizational) and
(vi) Management (or Silvicultural)
Territorial: Blocks, Compartments and Sub-Compartments.
Compartments: smallest permanent Working Plan unit of management,
denoted by Arabic numerals
Sub-compartments: temporary nature, denoted by small alphabet letters
46
47. A range is a very important unit in the management and administration of
Forests.
Beat in the smallest functional territorial Units, and is the foundation of Indian
forest administration.
47
48. MANAGEMENT (SILVICULTURAL) CLASSIFICATION
(i) Working Circles
(ii) Felling Series
(iii) Cutting Section,
(iv) Coupes
(v) Periodic Blocks.
Working Circle: The units of forest management is a Working Plan, usually
covering an area of a Forest Division
Each F.S. is a self-contained unit of management with a separate calculation
of yield and a separate series of silvicultural operations
Felling series in uniform forest: Periodic block-fixed and floating
48
49. Rotation: types
Choice of rotation:
Rotations controlling the supply of certain services i.e., the Silvicultural
and Physical Rotation.
Rotations controlling the output of material forest products in form or
quantity i.e., the Technical and maximum volume rotations.
Rotations controlling the financial returns, i.e., the Rotations of maximum
Gross or net Income and the Financial Rotation.
Trinity of norms’ in the Normal Forest: normal age class, growing stock
and increment
Normal growing stock volume but abnormal distribution of age-classes or
age-gradations is the worst form of forest abnormality.
Yield regulation: Focus only applicable in India
49
50. Agroforestry
A land use system that integrates trees, crops and animals in
such a way that is scientifically sound, ecologically desirable,
practically feasible and socially acceptable to the farmers (Nair
,1979).
50
55. Organized research started in eighties when ICAR launched AICRP
on AF in 1983
ICAR- CAFRI (earlier known as NRC for AF) established in 1988 at
Jhansi (UP).
AF Research & Education in most of the SAUs
Indian Council of Forestry Research and Education (ICFRE), its
regional centres, private institutions, NGOs and co-operatives e.g.
WIMCO, ITC, BAIF, IFFDC, West Coast Paper Mills Ltd.,
Hindustan Paper Mills Ltd., Tree Growers Cooperatives are also
engaged in promotion of AF in the country.
AF Research in India
55
56. All India Coordinated
Research Project on
Agroforestry - 1983
Coordinating Unit : CAFRI
Total centres : 37 representing all
agro-climates of India
Regions
•Himalayan : 08
•Indo-gangetic : 05
•Humid & sub-humid : 06
•Arid & semi-arid : 10
•Tropical : 08
56
57. Agroforestry practices Suitable climates
Multistorey including home garden Mainly in Humid and moist sub-humid
climates
Plantation crop combinations Humid to moist sub-humid climates
Boundary Plantation All regions
Hedgerow intercropping, barrier hedge Humid, sub-humid, possibly in semi-arid
climates
Trees and erosion control structure All climatic conditions
Windbreaks and shelterbelts Semi arid zone
Silvipastoral practices Semi arid, humid and sub-humid
Hortipasture Hilly areas
Home Gardens Tropical regions
Reclamation forestry All climatic conditions
Shifting cultivation Tropical areas
Scattered trees on farms All regions, especially semiarid and arid
Aqua Forestry Low lands
Combinations of the above in integrated
watershed management
All climatic conditions
Suitable Major Agroforestry systems of Different Regions
57
58. Promising AFS of India
Himalayas-
Silvipasture and Horticulture
Based system
Indo-Gangetic-
Poplar, Eucalyptus
Semi-arid & arid-
Aonla, Ailanthus, Neem, Shisham
Tropical region-
Teak, Casuarina, Melia
Humid & sub-humid-
Gmelina, Bamboo
58
59. Nutrient cycling is the transfer of minerals
in and out among the various nutrient pools.
It is a continuous process. It is not 100%
efficient; there are always leaks or losses
Agroforestry systems promote more
closed nutrient cycling than agricultural
systems by:
Uptake and recycling: taking up soil
nutrients by tree root systems and recycling
them as litter, including root residues
Synchronization: helping to synchronize
nutrient release with crop requirements by
controlling the quality, timing and manner of
addition of plant residues.
Nutrient Cycling in Agroforestry System
59
60. Controlling soil erosion
Maintain soil organic matter and
soil physical properties
Augment nitrogen fixation and
soil nutrient inputs
Promote efficient nutrient cycling
Reduce soil toxicities
Promote desirable soil faunal
activity
Augment soil water availability
to crops
Role of agroforestry systems in influencing overall soil
quality
60
61. Shifting cultivation: It is prevalent in many parts of Africa, Latin America,
South-East Asia and Indian subcontinent.
In India it is prevalent in Assam, Meghalaya, Jharkhand, Manipur, Orissa,
Nagaland, Chattisgarh, M.P., Arunachal Pradesh, Andhra Pradesh, Mizoram,
Tripura, Kerala, West Bengal, Sikkim.
It is known as ‘jhuming’ in North-east, ‘khallu / kurwa’ in Jharkhand and
‘dahiya’ or ‘podo’ in Orissa, Andhra Pradesh.
Agroforestry practices come in many forms but fall into two groups viz., first,
is those that are sequential such as shifting cultivation, fallows and second,
those are simultaneous such as alley-cropping.
61
62. Taungya System of cultivation:
This is a modified form of shifting cultivation in which the labour is
permitted to raise agri-crops in an area but only side by side with the forest
species planted by it
The taungya system was used primarily as an inexpensive means of
establishing timber plantations but is finally a recognized AF system.
The taungya (taung = hill, ya = cultivation) is a Burmese word coined in
Burma in 1850.
The system was introduced to India by Brandis in 1890 and the first taungya
plantations were raised in 1896 in North Bengal.
62
63. Desirable characteristics of multipurpose tree species
Management of trees in agroforestry
Thinning
Pruning • Removal of live or dead branches or multiple leaders from standing trees
for the improvement of the tree or its timber.
Natural pruning ; natural death and fall of branches of standing trees grown closely
due to deficiency of light or decay etc
Artificial pruning: Removal of branches with sharp tools in a dense crop.
Pollarding: Pollarding consists of cutting a pole tree at some height above the
ground level so that it produces new shoots from below the cut. Pollarding is done
at a height of 2- 2.5 m above ground level; e.g. in Salix spp., Hardwickia binata,
Grewia optiva, Morus alba, etc.
Lopping: Removal of one year shoots or fresh growth from entire crown of the
tree/plant in order to get sufficient fodder for livestock is known as lopping.
Lopping is extensively done in Morus, Grewia, Bauhinia, etc.
63
64. Coppicing: Cutting or heading back of main stem at 30 cm from the ground level.
Strong coppicers: Acacia catechu, Albizia lebbek, Anogeissus latifolia, etc.;
Good coppicers: Aesculus indica, Chloroxylon swietinia, Hardwickia binata, etc.;
Bad coppicers: Adina cordifolia, Bambax ceiba, etc.; and
Non coppicers: Mostly conifers.
Bending: Restricting the development of bole to allow more food material to new
leaf shoots. Bending and coppicing are useful when it is desirable to produce
large quantity of foliage close to ground level.
Training: In agroforestry vertical spread of the tree is a desirable feature, therefore
trees raised in agroforestry systems must be vertically trained to avoid shade and
light competition to underground crop.
Bushing: Horticulture operation commonly used to increase fruit production at a
convenient height for harvesting.
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