1) What do you mean by 'Forestry'? Give its classification.
The theory and practice of all that constitutes the creation, conservations and scientific management of forests and the utilization of their resources.
ii) Commercial or Production forestry: Timber and other raw materials.
iii) Social Forestry: Raising forests outside the traditional forests with the involvement of society.
iv) Farm Forestry: Raising forest trees on farm lands. It is further classified as:
(a) Non commercial farm forestry: raising of trees by individuals for domestic needs (usually by the farmers).
(b) Commercial farm forestry: Farmers grow trees on commercial basis on farmlands.
(iv) Community forestry: Raising of forests on public or community land.
(v) Urban forestry: Management of public and private owned lands in and adjacent to urban centres. They have more aesthatic value.
(vi) Agro forestry: Cultivating forest trees along with agricultural crops
2) Define agroforestry. Give its benefits and explain its systems with suitable examples.
Agroforestry:
Agro forestry is defined as sustainable land management system which increases the yield of the land, combines production of crops (including tree crops) and forest plants and/ or animal simultaneously or sequentially on the same unit of land and applies management practices that are compatible with cultural practices of local population.1. Agri silviculture: This system includes tree crops and agricultural crops. The legumes particularly are grown along with tree crops in the agricultural land. Growing agricultural crops in the forests for a temporary period is an old system. In "Taungya system' this practice is being followed.
2. Silvipastoral system :It is the land management under which both trees, grass or seasonal fodder are grown simultaneously to promote animal husbandry.
3. Horti silviculture : In this system the fruit trees and forest species are grown together for ex. In the plantation of mango the teak plantation is undertaken.
4. Agri silvipasture: In this system on the lines of forest tree species the grasses are grown in between the lines agricultural crops are taken.
5. Horti silvipasture :This system includes fruit crops, forest tree species and grasses and other fodder crops.
6. Agri Horti silvipasture (Multipurpose) system :This system includes fruit trees, forest trees, grasses and agricultural crops. This is multipurpose system. The adoption of any system by a farmer depends upon the needs of his family and cattle, land and other resources available with him and other locality factors
3) Write in detail about shelter belts and wind breaks and give its benefits.
The success of dry crops depends upon the available moisture in the soil and the period of its availability. The moisture availability in soil depends upon the quantum of rainfall, the frequency of rainfall, the texture and tension capacity of soil and lastly the factors which control the evapotranspiration. The loss due to evaporation is sometimes varying high in exposed and wind swept tracts. The higher the wind velocity the higher the loss due to evaporation. This factor of wind velocity can be controlled by planting what are called shelter belts. These belts consist of rows of trees and shrubs, planted along the field borders at right angle to the prevailing high velocity of winds. In the peninsular region of the sub-continent, the prevailing high velocity winds are from the south west on the western half of the country and the northeast in the eastern half of the country. Therefore, the shelter belts can be planted northwest to southeast, in almost all localities.
The belts are three to five rows of trees and shrubs with a conical cross section, that is, towards the windward side shrubs and bushes are planted close to each other, the second row will have medium sized trees and the third row tall trees and then in the declining order. The effectiveness of the belts extends towards the leeward side up to 20 to 30 times the height of the belts.
Generally in the first row Agave, Sitaphal, Phalsa (Grewia spp.) and small flowering shrubs are planted at 0.5 to 1 m distance. Average height of this row is 1 to 2 m. In the second row trees of 5 to 8 mm height such as Sesbenia, Glyricidia, Subabbul are planted. The last row and middle row of the cone, tall trees of Eucalyptus, Casias are planted at 1.5 m to 2 m spacing whose height may reach up to 10 to 15 m. They are spaced at a 3 m distance.
The benefits accruing as a result of planting of shelter belts and windbreaks are:
1.They reduce the wind velocity blowing over the crops and this reduces the evaporation losses.
2. The reduction of wind velocity helps in large exposure of the stomatal apertures, thus extending the period of photosynthesis on the leaf surface. The higher photosynthetic activity helps in better and healthier growth of crops.
3. It is recorded that the dew formation in sheltered areas increases by 200 per cent. This is an important factor for the crops which thrive well in winter such as Sorghum, Horsegram etc.
4. The shelter belts provide a place for the snakes to live and multiply, which in turn prey on the rats, the major cause of damage to grain.
5. The birds nesting on the shelter belts are agencies to prey on the insect pests, which damage the crops, such as Bayes, who feed their young ones with insects. When the crop is harvested, the birds live on the seeds of weeds, thus reducing the weed population in the fields.
6. The birds nesting on the trees of the shelter belts, add good manure through their droppings.
7. There is perceptible movement of soil particles when the wind velocity is high. The shelterbelts by reducing the wind velocity, prevent such movement of the fine particles of top soil and effectively prevent wind erosion.
8. The species planted as shelterbelts yield fruit, fodder, fuel, small timber for the farmer and thus add to the agricultural income.
9. The belts regulate the weather by reducing high summer temperatures and increase the low temperatures of winter. 10. The continuous and vast stretches of shelter belts to the increased precipitation from cumulus clouds.
Planting of wind breaks
Rows of trees along field margins, as far as possible perpendicular to the most high wind velocity of the locality constitute wind breaks. Roughly seven per cent of the total area should be planted for effective protection. The breaks are raised by planting two close rows of fast growing deciduous and one parallel row of slow growing of loner living evergreens (Tamarind). As far as possible dense crowned tree species are to be selected.
Species suitable for wind breaks
Dry and arid regions
Casurina equisitifolia, Pongamia glabra, Azadirechta indica, Acacia planifrons, Tamarindus indien, Albizzzia lebbek, Tamaris articulata, Eugania jambolana, Sesbunia grandiflora, Moringa plarygosperma, Eucalyptus hybrid.
For coastal areas:
anacardium occidentale, acacia auriculiformis, thespesia populnea, cassin siamen.
Shrubs and grasses-
agave species, sesbania aegyptica, saccharum spp., Cynodon dectylon, Euleopsis binata and other fodder grasses.
Planting of shelter belts :-
Shelter belts should be in one or are rows of trees. As the sheltered area is 15 to 20 times the height growth, the protection afforded will many a time cross the fields of the fields of the farmer. Therefore, rising of these belts should be on a co-operative basis, as holdings are small. The practice of raising shelterbelts and wind breaks can be adopted before planning agriculture on treeless tracts or large farms. For this effort, the leadership has to be strong.
The belts are triangular in cross-section. Tall trees are planted in the centre and shorter ones along the sides. A mixture of species is advisable. As far as possible species should be selected on the basis of their coppicing power. Spacing should be I m for shrubs, 1.5 m for trees in rows, each row being 1.5 to 4 m apart and there should be five rows for proper protection.
4) What is meant by thinning? Explain different types, Objectives & Methods of thinning.
Thinning:
Thinning is one of the most important silvicultural operations comprising of felling or removals made in a immature stand, aimed at improving the growth and form of the trees that remain, without making a permanent opening in the canopy The thinning is of different types viz. mechanical, stick, ordinary, crown, free, maximum and advance thinning.
Types of thinning
1. Mechanical thinning:
It is usually adopted in case of regular crops in the early stages, when canopy differentiation is not so pronounced, hence trees are to be retained at a pre-determined spacing with almost no consideration to their growth potential.
2. Stick thinning:
A stick is passed between rows of trees and where it cannot be passed horizontally a tree has to be removed.
3. Ordinary thinning:
It is adopted in regular crop. It involves the removal of inferior individuals from the forest, beginning from the suppressed class, then dominated class and finally, if needed the dominants. Basic assumption is that the trees which lag behind in the struggle for existence must be removed..
4. Crown thinning:
Crown thinnings are carried out in regular crops. In this type, thinnings are primarily directed to the dominant trees in a way that the less promising individuals are removed in favour of the better growing ones, with the dominated suppressed individuals being retained, unless they are dead, dying or diseased. Crown thinning may be light or heavy crown thinning. In light type dead, dying, diseased trees and some dominants are removed so as to make enough space available for best growing individual. In heavy thinning it is heavier than light as it means the retention of only the best growing stems.
5. Free thinning:
In regular crop the best growth of evenly spaced selected stems (called elites or alpha stems) is concentrated with other items interfering with their growth being removed. Also known as elite thinning. Free thinning differs from crown thinning in a way that all the attention is on best growth of elite trees.
6. Maximum thinning:
It aims to concentrate the entire growth potential of the particular area on the retained stems, from an early stage, the number of such stems being kept at a minimum so that they are able to fully utilize the available growing space. However, it tends to lead to problems such as accelerated erosion, invasion of weeds and production of knotty timber.
7. Advance thinning:
It is usually carried out in regular crops. It involves thinning in anticipation of suppression. The basic object is that the trees should be removed before they actually adversely affect the better growing individuals.
5) Explain types of Taungya systems and write its advantages and disadvantages.
Taungya system was first evolved in Burma in 1850 for raising teak plantations, shifting cultivation.
Types of Taungya system:
1. Departmental toungya:
In this system, an agricultural crop is raised by the Forest Department, together with the plantation, by employing a number of laborers' on daily wages. The main aim of raising crop is to keep down weed growth.
2. Leased taungya:
The plantation land is given on lease to the person or group of persons, who offer highest money, for raising crops for a specific number of years.
3. Village taungya:
This has been proved to be the most successful type. In this, the agricultural crop is raised by the people who have settled down in a village inside or near the forest, for this purpose. Usually each family is allotted between 0.8 to 1.5 ha land to raise trees and cultivate crops (up to 3 or 4 years). The family works on the land for a few years, during which it is responsible for raising the forest plantation. After, this allotted another patch of land to work on.
Advantages of Taungya system:
Disadvantages of Taungya system:
6) Define Silviculture and explain its objectives.
Silviculture pertains to the raising, development, care, reproduction and overall management of forest crops. OR The term silviculture, in English refers only to certain aspects of the theory and practices of raising of forest crops.
Objects of Silviculture:
Study of silviculture helps to attain the following objects:
1. To derive environmental benefits: Soil and water conservation, control of air and noise pollution, wild life conservation, regulation of climatic conditions, regulation of water cycle.
2. Raising species of more economic value: Industrial and economic growth through.
3. Production of high quality timber: Silviculture techniques help of avoid the of crooked, malformed, diseases or defective timber and thus help to produce good problems quality timber.
4. Production of more volume per unit area: Unmanaged forests may be too dense or too open, less production, premature death of trees silviculture helps to solve these problems.
5. Reduction of rotation period: In unmanaged forests the rotation tends to be longer.
6. Afforestation of blank areas: Waste lands can be used for forests.
7. Creation of plantation: Manmade forests or plantations may be created in place of natural forests.
8. Introduction of exotics: Successful introduction of exotic species is possible.
9. Employment potential: In any plantation operation, the labour component accounts for 60 to 70% of the total financial input.
10. Increase in the production of fuel and fodder: In developing countries like India it is important aspect.
11. Forest industries: Resin for resin and turpentine industry, pulp wood for paper industry, industrial wood for match and timber industry, railways etc, minor forest product based industries.
7) What is meant by regeneration of forests? Explain Natural & Vegetative method of regeneration.
Natural regeneration is the renewal of a forest crop by means of the natural process of seed sowing, or by coppice shoots or root suckers. In case of seed regeneration the steps are seed production, seed dispersal, seed germination and seedling establishment. The seed production depends upon species, age of the trees, size of crown, climatic and other locality factors. The seed may be dispersed by various agencies like, wind, water, gravity, birds, animals etc. The dispersed seed germinates under favourable conditions. Further, for the establishment of seedlings following factors affect directly or indirectly.
1. Root development: Proper root development is essential.
2. Light conditions: Light requirement varies from species to species. It increases with age of seedlings.
3. Soil conditions: Soil moisture, nutrients and aeration play important role.
4. Competition: Competition with grasses, weeds and within crop seedlings of thickly planted.
5. Other factors: Temperature, precipitation etc. affect.
The natural regeneration is carried out in different silviculture systems viz. clear felling, clear strip system, selection system, shelter wood system. In India the important forest species in which natural regeneration iscarried are Acacia, bamboos, Casuarina, Deodar, Dalbergia, Chaffa, Pines, Sandle wood, Shorea robusta (sal), teak, terminalia etc.
The natural regeneration is also followed by vegetative methods viz. Coppice, root sucker, cutting, layering, budding. Among these the coppice is the common method followed in forests. Coppice is of two types
i) Seedling coppice and
(ii) Stool coppice.
Good coppicer species are Acacia, Albizia, Neem, Nilgiri, teak, sal, jambhul, Aonla, Bad coppicers are Bombax ceiba, Casuarina, Gondan. Non coppicers are Deodar, pinus spp. is a form of exploitation of labour.
8) What is meant by forest mensuration? Explain diameter measurement of tree. Write Advantages & Disadvantages of Diameter tape.
The measurement of trees and forests is fundamental to the practice of forestry and forest science throughout the world. Measurements are used to understand how forests grow and develop, to determine how much they contain of the products man wants from them and to ensure that they are managed appropriately.
The diameter of a tree provides a measure of tree performance and is a useful starting point for estimating tree volume. By convention, the diameter of forest trees is measured in cm at 1.3 m above the ground and is termed the "Diameter at Breast Height" (DBH). Because trees are measured with the bark on this is also called the Diameter at Breast Height Over Bark (DBHOB). When measuring live trees most information is presented as overbark dimensions.
Where we are interested in the wood volume it is possible to estimate the depth of the bark (by cutting through the bark to the wood or observing the bark of recently felled trees) and converting DBHOB to the Diameter at Breast Height Under Bark (DBHUB). DBHUB-DBHOB (Bark Thickness x 2) Diameter At Breast Height (Dbh)
How to measure DBH
The MTG D-tape has scales on both sides. The yellow side shows a normal metric scale in cm. The white side is specially marked to show the diameter (cm) of a tree or pipe when it is wrapped around the circumference. To measure DBH first of all determine where "breast height" or 1.3m is on you.Then, standing on the up-slope side of the tree, wrap the tape around the tree at that height with the white side showing being careful not to twist the tape. Read the diameter from where the diameter scale starts. Obviously the tape can be used to measure diameter at any point on a tree or log.
9) Write cultivation of: A) Neem, B) Teak tree on the following points:
i) Botanical Name,
ii) Family,
iii) Sowing & Plantation,
iv) Harvesting & Yield,
v) Uses.
10) a) Describe in short the Instrumental & non-instrumental methods of tree height measurement.
b) Describe the different crown forms of trees.
11) a) Define form factor and explain artificial and absolute form factor.
b) Enlist the salient features of Indian forest policy, 1988.
