Introduction to Forest: Forest Regeneration

1. Introduction to Forestry
(According to 5th Dean Syllabus)
Dr. Shailendra Bhalawe
Assistant Professor
Department of Agro-forestry
College of Agriculture, Balaghat
Jawaharlal Nehru Agriculture University, Jabalpur
(M.P.)

2. Forest Regeneration
Forest Regeneration: Regeneration is the renewal of forest crops by
natural or artificial means. It may be either natural or artificial
regeneration.

3. Regeneration:
1. Natural Regeneration 2. Artificial Regeneration
•Natural Regeneration:
•a. by Seeds
•b. By Coppices
•c. By Root suckers
•Artificial Regeneration:
• a. by Sowing
• b. By Planting

4. Coppicing is a traditional method of woodland management which exploits the
capacity of many species of trees to put out new shoots from their stump or roots if
cut down. Or
A growth of small tree that are repeatedly cut down at short intervals, the new
shoots are produced by the old stumps.

5. Root suckers are words for various kinds of shoots that grow from adventitious
buds on the base of a tree or shrub, or from adventitious buds on its roots
Suckers are shoots or small plants arising from the base of a larger plant.

6. 1.Natural Regeneration: Natural regeneration is
the renewal of forest crop by self sown seed or
coppice or root suckers. It also refers to crop so
obtained. Seedling crop is a crop consisting of
seedling neither of planted not of coppice or root
sucker origin but originating in situ from natural
forest.
A. Natural Regeneration
from Seed: Seed is the
matured ovule which acts as
propagule for propagation of
plants.

7. Natural regeneration from seed depends
on various factors viz.,
Seed production,
Dispersal,
Germination,
Establishment and
Other external factors.

8. a. Seed production: Seed production of a species depends on species,
age, size of crown and climate.
1.Species: The silvicultural and genetic characters influence seed of a
species. Certain species produces seeds every year (Neem), whereas
some species produces biannually or at an interval of 3-5 years.
2.Age: Plant age has direct correlation with seed production. Young
and over matured trees yield poor quality seeds in meager quantity. The
middle aged trees give sufficient and good quality seeds.
3. Size of the crown: The bigger the crown means higher the
possibility to get maximum seeds from the trees. This enhances more
entrapment of solar energy which helps photosynthesis.
4. Climate: Climate element has positive correlation with seed yield.
The favourable climate enhances plant establishment, flowering and
seed production. The adverse factors such as heavy wind and drought
decreases seed production.

9. B. Seed dispersal: Seed dispersal refers to the
movement of seed materials from one place to other
through various dispersing agents. The various agents
involved in the seed dispersal are wind, water gravity,
birds, animals and human beings.
Ex- Seed dispersal by wind: conifers, Acer, Populus,
Bombax ceiba
Ex- Seed dispersal by Water: Mangrove spp., teak,
Jamun
EX-Seed dispersal by gravity: Oak, Juckulans regia
Ex-Seed dispersal by birds: Prunus, Mulbery,Trema
Ex-Seed dispersal by Animal: Acacia Arabica, Prosopis,
Zizyphus

10. C. Seed Germination: The growth process of a mature seed,
characterized by the emergence of a stem and root from it is called as
germination. It is process whereby the seed sprouts and begin to grow.
Germination in plants refers to the process by which a seed begins to
sprout and grow into a seedling under the right growing condition.
Germinative capacity is the percentage by number of seeds in a given
sample that actually germinate, irrespective of time.
Germinative energy is the percentage by number seeds in a given
sample that have germinated up to the time when the rate of
germination reaches its peak.
Plant percent is the percentage by number of seeds in a sample that
develop into seedling at the end of first growing season.
Seedling year is defined as a year in which a given species produces
abundant first year seedling.

11. Factors affecting seed germination:
i)Internal factors:
1) Permeability to water: The impermeability of
seeds to water prevents seed germination and vice
versa.
2) Permeability of embryo: In some species,
germination immediately after harvest is not
common because of immature embryo inside. It takes
some time for embryo development after its
maturation. E.g. Frasinus florifunds.
3) Permeability to oxygen: The impermeability of
seeds to oxygen prevents seed germination and vice
verss.

12. 4) After ripening processes: Certain seeds requires after
ripening process for its fullest development. In these seeds,
germination is possible after completion of this period only.
E.g. Juniperus macropoda.
5) Viability: Viability of the seed refers the potential
capacity of the seed to germinate. Generally, recalcitrant
seeds have less viability whereas orthodox seeds have
longer seed viability.
6) Size of seed: Bigger seeds generally give higher
germination percentage than small seeds. It is a general
thumb rule but this varies with different species.

13. External Factors:
1.Moisture:
2. Air:
3. Temperature:
4. Light:
5. Seed Bed:

14. 1.Moisture: Moisture is very essential in order to initiate the primary
biochemical reaction necessary for seed germination. It is also required
for shoftening of seed coat and leaching out of unwanted chemicals in
it. Excess soil moisture creates anaerobic conditions and dry condition
causes desiccation of seeds and hence both are not suitable for seed
germination.
2. Air: Soil air is essential for the respiration of living seeds. Hence,
optimum soil aeration is essential for seed germination.

15. 3. Temperature: Low temperature inactivated the living cells whereas
high temperature destructs the enzymes and kill the plants. Hence,
High and low temperature does not favour seed germination.
4. Light: Germination is in dependent of light mostly. But after
germination light essential for food germination through
photosynthesis by young seedling. There are certain species, which
requires light for its germination. E.g. Albizzia process, Cassia fistula.
5. Seed Bed: In order to get better germination, the seed beds are
prepared using well drained loamy soil in such a way that it could
provide optimum air, moisture and physical support for the
germinating seeds.

16. D) Seedling establishment: Seedling establishment refers to the development of new
crops naturally or assisted to a stage when the young regeneration, natural or artificial
is considered safe from normal adverse influences such as frost, drought or weeds and
no longer needs special protection or tending operation other than cleaning, thining
and pruning. Seedling establishment period is the period that elapses between the
initiation of natural regeneration and the time when it is considered safe from adverse
influence such as frost drought or weeds. The establishment of seedling is influenced
by many factors and are given hereunder:
1. Soil conditions and characteristics:
2. Climatic factors:
3. Presence of Weeds:
4. Grazing and browsing:
5. Burning:
6. Drip:
7. Competition
of crop:
9. Development of roots:
8. Composition of crop:

17. 1. Soil conditions and characteristics: Optimum soil conditions such
as good drainage, moisture, aeration and nutrient status facilitates
better establishment of seedlings. Shallow depth, stoniness and erosion
has adverse effect on the seedlings establishment.
2. Climatic factors: Climatic elements such as rainfall, light wind etc.
determine the establishment and development of vegetation. Optimum
light condition in terms of light duration and quality is needed for
better establishment of seedlings. Extreme temperature is not ideal for
seedling establishment. Rainfall determines the availability of moisture
to seedling. Hence sufficient rainfall with uniform distribution is
essential for better establishment.
3. Presence of Weeds: A severe weed condition prolongs the seedling
embellishment of seedling because it reduces the availability of
moisture, nutrients, light and space.
4. Grazing and browsing: Grazing causes destruction to embellished
seedlings in an area. In order to reduce the grazing impact fencing is
inevitable.

18. 5. Burning: Forest fire destroy the seedlings and causes seedling
mortality. Protection of planted areas from fire is inevitable for any
afforestation programs.
6. Drip: It refers the uprooting of seedlings by rainfall drop from the
tree crown/leaves. It is highly harmful for the establishment of
seedlings.
7. Competition of crop: In mixed forest/plantation, competition by
the next crop determines the establishment of seedling concerned. In
general, intense competition decreases the embellishment of seedling.
E.g. Clerodendron for Sal and Strobilanthus for teak.
8. Composition of crop: Mixed crop composition enhances better
seedlings establishment than the monocropping.
9. Development of roots: After germination, seedlings develop both
roots and shoots. Higher the development of roots facilitates better
establishment of seedlings. This depends on the genetic characteristics
of the species concerned.

19. (II) Natural regeneration by coppices:
Specific plants regenerates themselves by vegetative parts i.e.,
other than seeds. This kind of natural regeneration arises either from
coppices or root suckers. Vegetative reproduction has its own
advantages and limitations. Coppice can be of either seedling coppice
or stool coppice.
Seedling coppice: It is defined as the coppice shoots arising from the
base of the seedlings that have been cut or burnt back.
Stool coppice: refers to the coppice arising from a living stump or
stool. Generally each stump produces many coppices. These coppices
can be reduced in to one or two poles at the end of first year to obtain a
good, clear pole.
Among these two poles, one good pole is retained at the end of
second or third year and it can be retained up to the end of rotation.

21. Factors affecting the regeneration from coppices:
•Species: Coppicing ability of the species vary according to its genetic
makeup or inherent nature. Based on this, plant species are classified as
strong coppice, fair coppice, bad coppicer and do not coppice.
•Age of the tree: Young trees and samplings produce good coppices
than the older trees due to the smooth bark in the outside.
•Season of coppicing: Coppicing little before the start of spring is
better. This provides sufficient growing period for the coppice
produced. Besides this, the stored food anchors the regeneration
activities in plant.

22. •Height of stump: Higher height of stump is liable to be damaged by
wild animals whereas low stump is susceptible to stump splitting,
termite attack and rotting. Hence an optimum stump height of 15-25
cm is ideal. This varies with species. Certain species (Casuarina
equisetifolia, Manilkara hexandra) produce good coppices when high
stump is retained.
•Method of cutting: Smooth clean cut without splitting along one
direction gives better coppies. This drains the rain water easily and
prevents rotting.
•Rotation: Coppicing vigour decreases with number of rotation.
Hence, with increasing rotation the coppicing ability of the tree
decreases. In addition to above factors, general climate, soil, fire,
grazing and browsing also affects the coppicing to some extent.

23. (III) Natural generation by root suckers: A secondary shoot, rising
from the roots of a certain tree or shrub species that can grow into a
mature individual is called as root suckers.
Root sucker method is not commonly applied for regeneration inside
the forest naturally.
This is applicable to Dyospyrous tomentosa and Dalbergia sissoo.
In this method, trenches are dug continuously or discontinuously
around the tree in such a way that it causes severing of roots.
The root suckers arise from these severed points are cared well to
develop in to a matured plant.
The plants produced are poor in root growth and are liable to wind
throw.

24. IV) Natural generation by Pollarding: Pollarding is a process of
severely cutting back the branches of a tree or shrub. It was originally
practiced to provide animal fodder or fire wood without killing the tree.
There are a number of reasons that you may want to pollard a tree or
shrub:
(1) To prevent it from outgrowing its allotted space in the garden,
(2) So that the tree produces less shade, and
(3) To keep it away from obstructions such as electric wires.

25. Also, pollarded trees can have attractive shapes, although
they are not to everyone’s taste. Finally, they live longer
than un-pollarded trees.
To pollard a tree it is best to start when the tree is young.
Cut down all the major branches to within a few inches of
the main trunk.
Numerous sprouts will grow from the stub.
Every year the new growth needs to be cut back close to
the original cut.
After a number of years a swollen head will develop and a
bushy leafy globe will form.
 Trees can be pollarded in the spring or in winter when the
tree is dormant.

26. Artificial Regeneration: Artificial regeneration is defined as the
renewal of a forest crop by sowing, planting or other artificial means.
Objectives:
•To reforest an area: Reforestation is defined as the restocking of felled
or other wise cleared woodland by artificial means.
•To afforest an area: Afforestation refers the establishment of a forest
by artificial means on an area from which forest vegetation has always
or long been absent.

27. Factors affecting choice of regeneration:
•Yield: For better volume and financial yield, artificial regeneration is
better.
•Crop composition: Where crop composition has to be changed to get
a better return, artificial regeneration is favourable.
•Risk of damage by pests: Where there may be danger of pure crops
being attacked by insects, parasites and fungi, natural regeneration is
preferable.
•Genetically consideration: If the quality of trees in the forest is to be
improved, artificial regeneration is essential.
•Time and cost: Natural generation should be preferable over artificial
regeneration in consideration with cost and time.

28. The artificial regeneration of forest crops is carried out in the
following ways: OR Essential Preliminary considerations:
•Choice of species
•Selection of site
•Choice of method of artificial regeneration
•Spacing
•Arrangement and organization of work

29. 1) Choice of species:
a. The tree species are selected according to the human needs such as
protection, production, aesthetic and other environmental
considerations.
b. The species should have good timber, economic and other useful
values
c. The species should be adaptable to the climatic conditions prevailing
in the area
d. The soil of the region is considered while selecting a species for
regeneration
e. The species should improve the soil fertility and reduce the soil
erosion
d. It should be resistant to pest, disease and other adverse factors

30. f. It should be easily established with least cost
g. It should be fast growing one
h. It should consider the prevailing succession stages
I. It should not produce any allelopathic effect on other
plants.
J. The species should not alter the floristic composition of
the forest
K. It should not become weed in future

31. 2) Selection of site:
The species environmental requirement should be
matched to site with respect to climatic, edaphic and local
conditions.
The consideration of local floral composition gives a good
idea about the site condition.
In addition to this, the approachability of the site,
topographical conditions and wildlife considerations are
taken into account while selecting a site for reforestation or
afforestation.

32. 3) Choice of the method of artificial regeneration:
The artificial regeneration can be done either through sowing or
planting. The choice of these methods depends upon the species to be
raised, conditions of the site, availability of seed, cost and other
parameters.
3a) Sowing:
3b)Planting:
3c) Stump planting:

33. 3a) Sowing:
Sowing is the process of planting seeds. Simply it refers to the scattering or
impregnating the seed over the ground for growing plants. However, good quality
seeds (clean and healthy seeds) should be selected to produce a high yield.
Advantage of sowing:
1.It consumes less time and costs.
2.Roots grow well without any constraints

34. Disadvantages of sowing:
1.It need huge quantity of seed.
2.Birds and animals eat the seed sown on the surface.
3.Seedling mortality is higher than the direct planting
4.Weed problem is higher.
5.Rate of growth of seedling is very slow and hence
seedling establishment period is longer.
6.The opening of forest to grazing takes longer time
which creates complications with local peoples.

35. Time of sowing:
Time of sowing determines the successful germination
and seedling establishment.
Sowing depth:
Deep as well as shallow sowing is not advisable.
Deep sowing prevents emergence of cotyledons from
subsurface to surface.
In case of shallow sowing, seed are liable to be eroded
during watering and are also liable to be eaten by birds.
More precisely, seed can be generally sown into the
soil at a depth of about 2-3 times the size of the seed.

36. 3b)Planting: Planting refers to the act or operation of setting the
seedling in the ground for propagation of plants.
Planting time: Climate plays a deciding role in determining the
appropriate planting time. Newly planted trees do best when exposed
to moderate temperature and rainfall. Seedling need time to root and
acclimatize before the onset of intense heat and dryness of summer or
the freezing temperature of winter. Hence, early spring or onset of
monsoon is the best time for planting. In case of localities having
severe winter, it is better to plant before the snow fall. This also varies
with location to location and species to species. Planting may be of
many one of the following kinds.
1.Monsoon planting
2.Pre-monsoon planting
3.Winter planting
4.Spring planting

37. Planting methods:
The most common mistake when planting a tree is digging of a hole, which
is both too deep and too narrow. In deep pits, roots don’t have access to sufficient
oxygen to ensure proper growth. In case of narrow pits, root structure can not expand
sufficiently to nourish and properly anchor the tree. As a general rule, tree should be
transplanted no deeper than the soil in which they were originally grown. The width
of the hole should be at least 3 times the diameter of the root ball or container. This
facilitates root establishment.
(I)Planting an entire plant: In this method, the whole plant is lifted from the
nursery bed and planted in the field for further growing. This is done in any one of
the following methods.
a) Planting naked root seedling: In this method, the seedling is safely removed
from the nursery bed and soil around the root is removed. Thereafter the roots are
treated with bio-fertilizers and or fungicide before going for planting. These
seedlings are planted in the centre of the pits prepared in the field. While planting,
the roots of the seedlings are spread out and soil is pressed compactly so as to get a
good contact. The collar region of the seedlings should be 2-5 cm above the ground
level. This method of planting could not yield better results for many species and
hence not widely used.

38. b)Planting seedlings with ball of earth: Ball planting is defined as
the planting of seedlings with a ball of earth containing their roots
without any disturbance to roots. For this purpose, the mature
seedlings are detached from the wetted nursery bed with a ball of earth
of sufficient size. This is planted in a similar way as described above
in the naked seedling planting. The main disadvantage with this
method is the damage of ball during transportation. This method is
somewhat labour intensive process.
c) Planting seedling in containers: this is the safest method of
planting among all kinds of planting. The plant containers may be of
donas, basket, polybags or anything else. In this method of planting,
the plant containers are removed before planting in the pits without
disturbing the roots.

39. Stump planting:
Seeding of 1-2 cm diameter or pencil size collar thickness are suitable for
stump preparation. The seedling should have only one tap root system with 30 cm or
more length. Seedling with two or more tap root are discarded. The shoot of selected
seedling are cut at 2 cm above the collar region and removed. Similarly all the lateral
and secondary roots are removed by a sharp cut. There after the tap root is cut at a
length of 22 cm from the collar region. This stump can be treated with bio-fertilizer
inoculants and or pesticides for better protection.
Advantage of stump planting:
1.It is easier and cheaper one
2.Transport of planting stock is simple
3. It required less labor
4.Soil preparation in the field is easier
5. Seedling establishment and growth is faster
6. Root development is good and deep.

40. Thank You