INTRODUCTORY

FORESTRY
 INTRODUCTORY
FORESTRY

Alok Kumar Patra

Professor (Agronomy)
All India Co-ordinated Research Project
on Integrated Farming Systems
Odisha University of Agriculture & Technology
Bhubaneswar-751 003, Odisha

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Preface
Forest provides habitats for animals and livelihoods for humans. Forest
can influence weather patterns. Forest supplies wood, food and fodder, and
contributes indirectly to household food security, through the generation of
employment and income from the sale of forest products. So the forest is
a valuable ingredient in the economic and social fabrics of a country. The
importance of forest is now being realized in the backdrop of climate change
loss of biodiversity, and ecological and environmental imbalance. Thus
throughout the world, forestry is gaining importance as a subject of general
interest and many universities have recommended it as a core subject in their
curricula. Keeping this in view, this textbook Introduction to Forestry has
been written for the undergraduate students of agriculture as per the latest
ICAR syllabus.
The book has been divided into eight chapters covering major aspects
of forestry including definitions of basic terms related to forestry, forest
classification, Indian forest policies, forest regeneration, tending operations
forest mensuration, agroforestry and cultivation practices of some multipurpose
tree species. Any suggestion to improve the contents of the book will be
highly appreciated. I take full responsibility for any errors in this book. Any
shortcomings may be intimated so that it will be taken care of.
Originality of the contents in this book is not claimed. In writing this
book,a number of books, periodicals and journals have been referred. I extend
my sincere thanks to the authors and editors of these books and journals.
Every care has been taken to cite the bibliographic references. However, any
omissions, misrepresentations, incorrect citations or other mistakes that may
have occurred are regretted.
I am grateful to my colleagues in the All India Coordinated Research
Project on Integrated Farming Systems, Odisha University of Agriculture &
Technology, Bhubaneswar for their help in various ways during the preparation
of this textbook.
I express my gratitude to the New India Publishing Agency, New Delhi for
bringing out the book timely and neatly.
I express my indebtedness and gratitude to my parents who are a constant
source of inspiration. I am also thankful to my wife Jharashree and daughter
Prachurya for their support and encouragement.

ALOK KUMAR PATRA

OUAT, Bhubneshwar
Contents

Prefacev
Glossaryxi
Chapter 1 Forests and Forestry 1
• Development of modern forestry  1
• Forestry as a science 2
• History of forestry education 2
• Definitions of basic terms related to forestry 3
• Importance of forests 5
• General characteristics of forests 8
• Classification of forest  10
• Benefits of trees 12
• International institutes working in forest conservation
and research 14
Chapter 2 Status of Indian Forests 22
• History of Indian forests  22
• Present status of Indian forests 24
• Forest types of India 26
• Forest policies in India 31
Chapter 3 Forest Regeneration 45
• Natural regeneration 45
• Artificial regeneration 52
• Comparison between artificial and natural regeneration 66
• Choice between natural and artificial regeneration  66
• Crown classification  69
Chapter 4 Silvicultural Systems 71
• Objectives of silviculture 71
• Silvicultural system  72
• Clearcut system  73
• Seed tree system 75
viii Introductory Forestry

• Selection system  77
• Shelterwood system 81
• Coppice system 86
• Accessory silvicultural systems 89
• Conversions in silvicultural systems 90
Chapter 5 Tending Operations  92
• Weeding92
• Cleaning95
• Casualty replacement 96
• Liberation96
• Thinning97
• Improvement felling 103
• Pruning104
Chapter 6 Forest Mensuration 106
• Scope of forest mensuration 106
• Importance of forest mensuration in forest management 108
• Diameter measurement  109
• Height measurement 113
• Tree stem form 128
• Measurement of volume of trees 131
• Age determination of the trees 135
Chapter 7 Agroforestry  139
• Definitions of agroforestry 139
• Key traits of agroforestry practices  141
• Objectives of agroforestry 141
• Importance of agroforestry 142
• Scope of agroforestry in India 145
• Benefits from agroforestry 148
• Limitations of agroforestry 149
• Factors affecting the selection of tree species 150
• Criteria of selection of trees in agroforestry 153
• Suitable species for specific function  154
• Suitable species for agroforestry under different climatic
conditions  155
• Suitable species for agroforestry under different soil types 155
• Criteria of selection of annual crops in agroforestry 156
• Agroforestry systems 157
 Contents ix

• Agrisilvicultural systems 157

• Silvipastoral systems 170
• Agrisilvipastoral system 173
• Other agroforestry systems 175
Chapter 8 Cultivation Practices of Selected Multipurpose
Tree Species 177
• Mangium (Acacia mangium)  177
• Eucalyptus (Eucalyptus spp.)180
• Casuarina (Casuarina equisetifolia)183
• Poplar (Populus deltoides)185
• Teak (Tectona grandis)191
• Sissoo (Dalbergia sissoo)194
• Neem (Azadirachta indica)196
• Khair (Acacia catechu)199
• Tamarind (Tamarindus indica)201
• Phalsa (Grewia spp.)203
• Mulberry (Morus alba)205
• Oak (Quercus spp.)  208
Selected References 210

Index213
Glossary

Afforestation: Establishment of a forest in an area not forested earlier.

Agrisilviaquaculture: A form of agroforestry consisting of tree (woody
perennial), agricultural crop and freshwater aquatic animal components.
Agrisilviculture: A form of agroforestry consisting of tree and crop
components.
Agrisilvipasture: A form of agroforestry consisting of tree, crop and pasture/
animal components.
Agroforestry: A collective name for land use systems and technologies where
woody perennials (trees, shrubs, palms, bamboos, etc.) are deliberately used
on the same land management units as agricultural crops and/or animals, in
some form of spatial arrangement or temporal sequence.
Allelopathy: Any direct or indirect harmful effect that one plant has on another
or mutually on each other through the production of chemical compounds that
escape into the environment.
Alley cropping: A farming system in which arable crops are grown in alleys
formed by trees or shrubs, established mainly to hasten soil fertility restoration
and enhance soil productivity.
Annual plant: A plant that grows for only one season (or year) before dying in
contrast to a perennial, which grows for more than one season.
Annual ring: The combination of one early-wood layer (light coloured) and
one late-wood layer (dark coloured) seen in a cross-section of a tree. One
annual ring usually represents one year of growth.
Aquasilviculture: A form of agroforestry consisting of tree and aquatic
animals.
Artificial regeneration: The growth of new trees through seeding and
planting.
Basal area: The area of the cross section of a tree stem, including the bark
generally at breast height (1.37 m above the ground).
Billet: A piece of round wood about one meter in length usually cut for pulp
or firewood.
Bole: The main trunk of a tree.
Breast height: A standard height from ground level for recording diameter
girth, or basal area of a tree, generally 1.37 m.
xii Introductory Forestry

Browse: The buds, shoots, leaves and flowers of woody plants which are eaten
by livestock or wild animals.
Bush fallow: A fallow of usually 3-10 years in which the natural vegetation
regenerates which is composed principally of shrubs and young trees.
Buttress: An outgrowth from the base of a tree connecting it with the roots
especially common in tropical rainforest species.
C3 plants: Species with the photosynthetic pathway in which the first
product of CO2 fixation is the 3-carbon molecule, phosphoglyceric acid and
comparatively photosynthetically less efficient than C4 plants.
C4 plants: Species with the photosynthetic pathway in which the first product of
CO2 fixation is the 4-carbon molecule, oxaloacetic acid and photosynthetically
more efficient than C3 plants.
CAM (Crassulacean Acid Metabolism) plants: Species with stomata that
open primarily at night, and have organic acids, especially malic acid, as the
primary CO2 fixation products.
Cambium: A thin layer of specialized cells within a tree’s trunk that divide
to produce new inner bark cells to the outside and new sapwood cells to the
inside. The narrow band of cells that is responsible for the tree’s growth in
circumference.
Canopy: The foliar cover in a forest stand consisting of one or several layers.
Canopy closure: The ground area covered by the crowns of trees or woody
vegetation as delimited by the vertical projection of crown perimeters and
commonly expressed as a percent of total ground area (syn., canopy cover,
crown cover).
Carrying capacity: The maximum number of healthy wildlife that a given
habitat or area can support without degradation of the habitat.
Clean (or clear) bole: The part of a bole or stem which is free from branches.
Clearcut: A harvesting and regeneration method that removes all trees within
a given area. Most commonly used in pine and hardwood forests that require
full sunlight to regenerate and grow efficiently.
Clearcutting with reserves: A clearcutting method in which varying numbers
of reserve trees are not harvested to attain goals other than regeneration.
Clone: A group of plants originating from a single plant by vegetative
propagation and therefore all having the same genetic make-up.
Codominant crown: Trees with crowns forming the general level of the main
canopy in even-aged stands or, in uneven-aged stands, the main canopy of the
tree’s immediate neighbours, receiving full light from above and comparatively
little from the sides.
 Glossary xiii

Cohort: A distinct aggregation of trees originating from a single natural event

or regeneration activity, or a grouping of trees, e.g., 10-year age class, as used
in inventory or management.
Community forestry: A form of social forestry, where tree planting is
undertaken by community people on common lands for fuelwood, timber, leaf
fodder and other products that results in the improvement of community life.
Composition (stand): The proportion of each tree species in a stand expressed
as a percentage of the total number, basal area, or volume of all tree species
in the stand.
Conifer: A class of trees that are evergreen, have needle or scalelike foliage
and conelike fruit; often called softwood. Examples include pine, cedar and
cypress.
Contour hedgerow: Dense, narrow hedges of woody perennials, planted
along the contour of a slope to prevent soil erosion.
Coppice: A method of regenerating a stand in which all trees in the previous
stand are cut and the majority of regeneration is from sprouts or root suckers.
Coppicing: Cutting of certain tree species close to ground level to produce
new shoots from the stump. Also occurs naturally in some species if the trees
are damaged.
Coppice with reserves: A coppice method in which reserve trees are retained
to attain goals other than regeneration. The method normally creates a two-
aged stand.
Crop tree: Any tree that is selected to become a component of a future
commercial harvest.
Crown: The part of a tree or woody plant bearing live branches and foliage.
Crown class: A class of tree based on crown position relative to the crowns
of adjacent trees.
Crown cover: The ground area covered by the crowns of trees or woody
vegetation as delimited by the vertical projection of crown perimeters and
commonly expressed as a percent of total ground area (syn., canopy cover,
canopy closure).
Crown density: The amount and compactness of foliage of the crowns of
trees and/or shrubs.
Cull: The portion of a tree stem or log which is unmerchantable.
Cut-and-carry: Fodder or other plant products which are harvested and
carried to a different location to be used or consumed.
Cutting cycle: The planned interval between partial harvests in an uneven-
aged stand.
xiv Introductory Forestry

Deciduous plant: A plant that sheds all or most of its leaves every year during
a certain season.
Deforestation: Disturbance, conversion or wasteful destruction of forest
lands.
Dendrology: The study of trees and tree identification.
Dominant crown: Trees with crowns extending above the general level of the
main canopy of even-aged stands or, in uneven-aged stands, above the crowns
of the tree’s immediate neighbours, and receiving full light from above and
partly from the sides.
Earlywood: Wood cells produced at the beginning of a tree’s growing season
that is generally light in colour. Also called springwood.
Ecological succession: The gradual change of plant and animal communities
over time.
Ecosystem: All the plants and animals in a given area and their physical
environment, including the interactions among them.
Edge: The transition between two different types or ages of vegetation.
Emergent crown: Trees with crowns completely above the general level of
the main canopy receiving full light from above and from all sides.
Even-aged methods: Methods to regenerate a stand with a single age class.
Even-aged stand: A stand of trees containing a single age class in which the
range of tree ages is usually less than 20 percent of rotation.
Evergreen: A group of trees that do not lose all of their leaves every year but
go through a gradual replacement by dropping only their oldest leaves each
year. Instead of being bare in winter, these trees have leaves all year.
Extension forestry: The practice of forestry in areas devoid of tree growth
and other vegetation situated in places away from the conventional forest areas
with the objective of increasing the area under tree growth.
Farm forestry: Commercial tree growing by farmers on their own land.
Fixed-lift pruning: Complete pruning of all branches below a prescribed
point on the stem of the tree. The lift is specified as height from the ground
and the choice of height is based on the shape of development attained by the
stand.
Fluting: Stem shows irregular involutions and swellings. It is considered a
serious defect for timber production.
Fodder: Parts of plants which are eaten by domestic animals, these may
include leaves, stems, fruit, pods, flowers or pollen.
Foliage: The mass of leaves of plants, usually of trees or bushes.
 Glossary xv

Forest: A forest is a large area dominated by trees.

Forest fallow: A longer fallow, usually of several years, in which the naturally
regenerated vegetation is composed principally of larger or mature trees.
Forest floor: The lowest level of the forest that is made up of tree seedlings,
dead leaves and needles, grasses, ferns, flowers, fungi, and decaying plants
and logs.
Forest garden: A land-use form on private lands outside the village in which
planted trees and sometimes additional perennial crops occur.
Forest health: A forest condition that has overall structure, function, and
characteristics that enable it to be resilient to disturbance and to maintain
normal rates of change commensurate with its stage of development.
Forest type: A designation or name given to a forest based on the most
abundant tree type or types in the stand; groups of tree species commonly
growing in the same stand because their environmental requirements are
similar
Forestry: Forestry is the science and craft of creating, managing, using,
conserving, and repairing forests, woodlands, and associated resources for
human and environmental benefits.
Free thinning: The removal of trees to control stand spacing and favour
desired trees using a combination of thinning criteria without regard to crown
position.
Group selection: A method of regenerating uneven-aged stands in which
trees are removed, and new age classes are established, in small groups. The
maximum width of groups is approximately twice the height of the mature
trees, with small openings providing microenvironment suitable for tolerant
regeneration and the larger openings providing conditions suitable for more
intolerant regeneration.
Group selection with reserves: A variant of the ‘group selection method’
in which some trees within the group are not cut to attain goals other than
regeneration within the group.
Habitat: An area in which a specific plant or animal naturally lives, grows
and reproduces; the area that provides a plant or animal with adequate food,
water, shelter and living space.
Hardening off: Measures taken to prepare plants raised in a nursery for
planting out in the field.
Hardwoods: Trees with broad, flat leaves as opposed to coniferous or needled
trees. Wood hardness varies among the hardwood species, and some are
actually softer than some softwoods.
xvi Introductory Forestry

Heartwood: The central core of a tree, which is made up of dense, dead wood
and provides strength to the tree.
Hedgerow (or hedge): A closely planted line of shrubs or trees, often forming
a boundary or fence.
High-grading: A harvesting technique that removes only the biggest and
most valuable trees from a stand and provides high returns at the expense of
future growth potential.
Homegarden: A land use form on private lands surrounding individual houses
with a definite fence, in which several tree species are cultivated together with
annual and perennial crops, often with inclusion of livestock.
Hypsometer: Any device used for measuring tree height.
Indigenous: Native to a specific area; not introduced.
Intermediate crown: Trees with crowns extending into the lower portion of
the main canopy of even-aged stands or, in uneven-aged stands, into the lower
portion of the canopy formed by the tree’s immediate neighbours, but shorter
in height than the codominants. They receive little direct light from above and
none from the sides.
Intermediate treatment: A collective term for any treatment designed
to enhance growth, quality, vigour, and composition of the stand after
establishment or regeneration and prior to final harvest.
Latewood: Wood cells produced at the end of the growing season that make
up the darker section of an annual ring. Also called summerwood.
Layering: Method to stimulate growth of roots on shoots or twigs in order to
propagate the layered plant true to type.
Litter: Layer of decomposing plant material (leaves, branches etc.) covering
the ground, especially under trees.
Log: The stem of a tree or a length of stem or branch after felling and trimming.
Lopping: Cutting one or more branches of a standing tree or shrub.
Low thinning (thinning from below): The removal of trees from the lower
crown classes to favour those in the upper crown classes.
Mechanical thinning (geometric thinning): The thinning of trees in either
even- or uneven-aged stands involving removal of trees in rows, strips, or by
using fixed spacing intervals.
Mother tree: Tree from which seeds or vegetative parts are collected to be
propagated.
Multipurpose trees: Trees yielding one or more products and offering
environmental benefits as well.
 Glossary xvii

Multistoried (or multistoreyed): Relating to a vertical arrangement of plants

so that they form distinct layers, from the lower (usually herbaceous) layer to
the uppermost tree canopy.
Natural regeneration: An age class created from natural seeding, sprouting,
suckering, or layering. The growth of new trees in one of the following ways
without human assistance: (a) from seeds carried by wind or animals, (b) from
seeds stored on the forest floor, or (c) from stumps that sprout.
Nurse tree (nurse crop): A tree, group or crop of trees, shrubs or other planes,
either naturally occurring or introduced, used to nurture, improve survival or
improve the form of a more desirable tree or crop when young by protecting it
from frost, insolation, or wind.
Nutrient pump: A deep tree root system, that takes up nutrients from deep
soil layers and brings them to the surface in the tree and its litter fall.
Overstorey (or overstory): The highest layer of vegetation, often the tree
canopy, which grows over lower shrub or plant layers.
Overstorey removal: The cutting of trees comprising an upper canopy layer
in order to release trees or other vegetation in an understorey.
Overtopped (suppressed) crown: Trees of varying levels of vigour that have
their crowns completely covered by the crowns of one or more neighbouring
trees.
Perennial plant: A plant that grows for more than one year, in contrast to an
annual, which grows for only one year (or season) before dying.
Phloem: The part of a tree that carries sap from the leaves to the rest of the
tree. Also called inner bark.
Pole: A tree between the size of a sapling and a mature tree.
Pollarding: Cutting back the crown of a tree in order to harvest wood and
browse to produce regrowth beyond the reach of animals and/or to reduce the
shade cast by the crown.
Precommercial thinning: A thinning that does not yield trees of commercial
value, usually designed to reduce stocking in order to concentrate growth on
the more desirable trees.
Prick out: Transplant seedlings from seed trays or seedbeds into nursery beds
or pots.
Propagule: A part of a plant that can give rise to a new plant.
Protective plant: Plants grown to protect crops, soil or land from adverse
environmental factors.
xviii Introductory Forestry

Provenance: Germplasm from a single place of origin. Germplasm from

different provenances of the same species can differ in ways such as growth
habit, biomass production or drought hardiness.
Pruning: Cutting back plant growth, including side branches or roots.
Pulpwood: Wood used in the manufacture of paper, fibreboard or other wood
fibre products. Pulpwood-sized trees are usually a minimum of 4 inches in
diameter.
Pure stand: A stand composed of essentially a single species.
Recalcitrant seed: Seed that has to be sown fresh because it loses its viability
rapidly; e.g., that of many large seeded tropical fruits.
Recreation forestry: The practice of forestry with the objectives of raising
flowering trees and shrubs mainly to serve as recreation forests for the urban
and rural population.
Reforestation: Establishment of trees on ground that has been recently cleared
of trees.
Regeneration: The renewal of a forest crop by natural or artificial means
Regeneration (reproduction) method: A cutting method by which a new age
class is created. The major methods are clearcutting, seed tree, shelterwood,
selection, and coppice.
Regeneration (reproduction) period: The time between the initial
regeneration cutting and the successful reestablishment of a new age class by
natural means, planting, or direct seeding.
Regular uneven-aged (balanced) stand: A stand in which three or more
distinct age classes occupy approximately equal areas and provide a balanced
distribution of diameter classes.
Release: To free a tree from competition with its immediate neighbours by
removing the surrounding trees. This occurs naturally and artificially.
Reserve trees (green tree retention): Trees, pole-sized or larger, retained in
either a dispersed or aggregated manner after the regeneration period under
the clearcutting, seed tree, shelterwood, or coppice methods.
Resin: A group of sticky liquid substances secreted by plants that appear on
the plant’s external surface after a wound.
Resource capture: The processes by which plants obtain light, water and
nutrients.
Root ball: The network of roots and the soil clinging to them when a plant is
lifted from the soil or removed from a container.
 Glossary xix

Root pruning: The root pruning of seedlings in a nursery bed to limit the
extension of roots in depth or laterally.
Root sucker: A shoot arising from the root of a plant.
Rotation (in forestry): The length of time between establishment and
harvesting of a tree.
Salvage cut: The harvesting of dead or damaged trees, or the harvesting of
trees in danger of being killed by insects, disease, flooding or other factors in
order to save their economic value.
Sanitation cutting: The removal of trees to improve stand health by stopping
or reducing actual or anticipated spread of insects and disease.
Sapling: A tree, usually young, that is larger than a seedling but smaller than
a pole. Size varies by region.
Sawtimber: Wood of large enough size to be used to produce lumber for
construction and furniture.
Scarification: Mechanical removal of competing vegetation and/or interfering
debris, or disturbance of the soil surface, designed to enhance reforestation.
Seed tree: An even-aged regeneration method in which a new age class
develops from seeds that germinate in fully exposed microenvironments after
removal of all the previous stand except a small number of trees left to provide
seed. Seed trees are removed after regeneration is established.
Seed tree cut: A harvesting method in which a few scattered trees are left in
the area to provide seeds for a new forest stand. Selection of seed trees is based
on growth rate, form, seeding ability, wind firmness and future marketability.
This harvesting method produces an even-aged forest.
Seed tree with reserves: A seed tree method in which some or all of the seed
trees are retained after regeneration has become established to attain goals
other than regeneration.
Selection thinning (dominant thinning): The removal of trees in the
dominant crown class in order to favour the lower crown classes.
Selective cutting: The periodic removal of individual trees or groups of trees
to improve or regenerate a stand.
Selective pruning: Removal of some of the branches on the stem at various
levels above the ground according to a particular prescription.
Shelterbelts: A wind barrier of living trees and shrubs established and
maintained for protection of crop fields.
Shelterwood: A method of regenerating an even-aged stand in which a new
age class develops beneath the moderated microenvironment provided by the
residual trees.
xx Introductory Forestry

Shelterwood cut: Removing trees in the harvest area in a series of two or

more cuttings so that new seedlings can grow from the seeds of older trees.
This method produces an even-aged forest.
Shelterwood with reserves: A variant of the shelterwood method in which
some or all of the shelter trees are retained, well beyond the normal period of
retention, to attain goals other than regeneration.
Shifting cultivation: System of land use in which the site of cultivation is
regularly changed, with older sites reverting to forest or bush fallow.
Shrub: A woody plant that remains less than 10 meters tall and produces
shoots or stems from its base.
Silvicultural system: A planned process whereby a stand is tended, harvested,
and reestablished.
Silviculture: The art, science and practice of establishing, tending and
reproducing forest stands of desired characteristics. It is based on knowledge
of species’ characteristics and environmental requirements.
Silviculturist: A practitioner of forestry is known as a silviculturist or forester.
Silvipastoral system: A form of agroforestry systems consisting of the trees
(woody perennial) and pasture/animal components.
Single tree selection: A method of creating new age classes in uneven-
aged stands in which individual trees of all size classes are removed more-
or-less uniformly throughout the stand to achieve desired stand structural
characteristics.
Site class: A classification of site quality, usually expressed in terms of ranges
of dominant tree height at a given age or potential mean annual increment at
culmination.
Site index: A measure of actual or potential forest productivity expressed in
terms of the average height of a certain number of dominants and codominants
in the stand at an index age.
Size class: Tree size recognized by distinct ranges, usually of diameter or
height.
Slash-and-burn system: A technique for land clearing to prepare for planting
of annual food crops or trees.
Snag: A standing dead tree from which the leaves and most of the branches
have fallen.
Social forestry: The practice of using trees and/or tree planting specifically
to pursue social objectives, usually betterment of the poor, through delivery of
the benefits to the local people.
 Glossary xxi

Softwood: A tree belonging to the order Coniferales. Softwood trees are

usually evergreen, bear cones and have needles or scalelike leaves. Examples
include pines, spruces, firs and cedars.
Stand: A contiguous group of trees sufficiently uniform in age class
distribution, composition, and structure, and growing on a site of sufficiently
uniform quality, to be a distinguishable unit.
Stand density: A quantitative, absolute measure of tree occupancy per unit of
land area in such terms as numbers of trees, basal area, or volume.
Stand improvement: A term comprising all intermediate cuttings made to
improve the composition, structure, condition, health, and growth of even- or
uneven-aged stands.
Stratified mixture: A stand in which different species occupy different strata
of the total crown canopy.
Stratum (canopy layer): A distinct layer of vegetation within a forest
community.
Suckers: A side shoot from the roots of a plant; a side growth arising from an
auxiliary bud.
Suppression: The process by which a tree loses its vigour due to inadequate
light, water and nutrients.
Taungya: Method of raising forest crops in combination with an agricultural
crop; the agricultural use to which the land is put does not generally continue
throughout the rotation of the forest crop but is confined to that period which
ends with the closing of the canopy of the forest crop.
Thinning: A cultural treatment made to reduce stand density of trees primarily
to improve growth, enhance forest health, or to recover potential mortality.
Tip pruning: Pruning of a branch at a point other than at its junction with the
stem.
Tree garden: Multistoreyed agroforestry systems in which a mixture of
several fruit and other trees are cultivated, sometimes with inclusion of annual
crops.
Two-aged methods: Methods designed to maintain and regenerate a stand
with two age classes. In each case the resulting stand may be two-aged or
tend toward an uneven-aged condition as a consequence of both an extended
period of regeneration establishment and the retention of reserve trees that
may represent one or more age classes.
Two-aged stand: A stand composed of two distinct age classes separated in
age by more than 20 percent of rotation.
xxii Introductory Forestry

Undercutting: The root pruning of seedlings in a nursery bed to limit root

depth extension.
Understorey: The area below the forest canopy that comprises shrubs, snags
and small tree. Because the understorey receives little light, many of the plants
at this level tolerate shade and will remain part of the understorey. Others will
grow and replace older trees that fall.
Uneven-aged selection methods: Methods of regenerating a forest stand,
and maintaining an uneven-aged structure, by removing some trees in all size
classes either singly, in small groups, or in steps.
Uneven-aged stand: A stand of trees of three or more distinct age classes,
either intimately mixed or in small groups.
Uneven-aged system: A planned sequence of treatments designed to maintain
and regenerate a stand with three or more age classes.
Variable-lift pruning: Complete pruning of all branches below a prescribed
variable point on the stem of the tree. This point may be specified either as a
proportion of the height or as a diameter limit.
Wildings: Wildings are planting materials collected from natural vegetation,
e.g., seedlings or cuttings.
Windbreak: A strip of trees or shrubs or crop plants serving to reduce the
force of wind and provide a protective shelter against wind.
Windsnap: Breakage of the tree bole (trunk) instead of uprooting is called
windsnap.
Windthrow: In forestry, windthrow or blowdown refers to trees uprooted or
broken by wind.
Wood chemicals: Chemicals that are found naturally in the various parts of
a tree.
Wood: The solid interior of a tree.
Wrenching: The disturbance of seedling roots in a nursery bed (e.g., with a
tractor-drawn blade) with the objective of stimulating the development of a
fibrous root system.
Xylem: The part of a tree that transports water and nutrients up from the roots
to the leaves. Older xylem cells become part of the heartwood. Also called
sapwood.
Chapter 1

Forests and Forestry

A forest is a large area dominated by trees. Many definitions of forest are used
throughout the world, incorporating factors such as tree density, tree height,
land use, legal standing and ecological function. Although a forest is usually
defined by the presence of trees, under many definitions an area completely
lacking trees may still be considered a forest if it grew trees in the past, will
grow trees in the future, or was legally designated as a forest regardless of
vegetation type. According to the Food and Agriculture Organization, forests
covered 4 billion hectares or approximately 30% of the world’s land area
in 2006. Forests are the dominant terrestrial ecosystem of earth, and are
distributed around the globe. Forests account for 75% of the gross primary
production of the earth’s biosphere, and contain 80% of the earth’s plant
biomass.

DEVELOPMENT OF MODERN FORESTRY

Systematic management of forests for a sustainable yield of timber began in
Portugal in the 13th century when Afonso III, the king of Portugal planted
the trees to prevent coastal erosion and soil degradation, and as a sustainable
source for timber used in naval construction. His successor Dom Dinis
continued the practice and the forest exists still today. Forest management
also started in German in the 14th century and in Japan in the 16th century.
The practice of establishing tree plantations in the British Isles was promoted
by John Evelyn during second half of the 17th century.
During the late 19th and early 20th centuries, forest preservation
programmes were established in British India, the United States, and Europe.
Sir Dietrich Brandis is considered the father of tropical forestry. He brought
European concepts and practices to the tropical and semi arid climate zones.
The enactment and evolution of forest laws and binding regulations occurred in
most Western nations in the 20th century in response to growing conservation
concerns. Tropical forestry is a separate branch of forestry which deals mainly
with equatorial forests that yield woods such as teak and mahogany. One of
the applications of modern forestry is reforestation, in which trees are planted
and tended in a given area.
2 Introductory Forestry

FORESTRY AS A SCIENCE
With the rise of ecology and environmental science, there has been a reordering
in the applied sciences. Forest ecosystems have come to be seen as the most
important component of the biosphere. In line with this view, forestry is a
primary land-use science comparable with agriculture. Forestry is the science
and craft of creating, managing, using, conserving, and repairing forests,
woodlands, and associated resources for human and environmental benefits.
The science of forestry has elements that belong to the biological, physical,
social, political and managerial sciences.
Modern forestry generally embraces a broad range of concerns, in what
is known as multiple-use management, including the provision of timber,
fuelwood, wildlife habitat, natural water quality management, recreation,
landscape and community protection, employment, aesthetically appealing
landscapes, biodiversity management, watershed management, erosion
control, and preserving forests as ‘sinks’ for atmospheric carbon dioxide.

HISTORY OF FORESTRY EDUCATION

The first forestry school was established by Georg Ludwig Hartig at Hungen
in the Wetterau, Hesse, Germany in 1787, though forestry had been taught
earlier in central Europe. In Spain, the first forestry school was the Forest
Engineering School of Madrid, founded in 1844. The Biltmore Forest School
in North Carolina was the first of its kind in North America, established
in 1898. Another early school was the New York State College of Forestry,
established at Cornell University, also in 1898. Before the establishment of
these institutions North American foresters used to go to Germany to study
forestry. In South America the first forestry school was established in Brazil
in 1962 under the Federal University of Parana. In India, forestry education
is imparted in the agricultural universities and in forest research institutes.
Forestry universities are now also established and they offer masters and
doctoral degrees in various branches of forestry. The International Union
of Forest Research Organizations is the only international organization that
coordinates forest science efforts worldwide.
Today a strong body of research exists regarding the management of forest
ecosystems and the genetic improvement of tree species and varieties. Forestry
studies also include the development of better methods for the planting,
protecting, thinning, felling, extracting, and processing of timber.