UNIT 7 FORESTRY AND OTHER LAND USES - eGyanKosh

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Agriculture, Forestry andOther Land Uses UNIT 7 FORESTRY AND OTHER

LAND USESStructure

7.1 Introduction

7.2 Objectives

7.3 Forests as Land-use

7.4 Deforestation7.4.1 Causes and Consequences of Deforestation

7.4.2 Effects of Deforestation on Environment

7.5 Mitigation Measures: Reducing Deforestation and Degradation

7.6 Afforestation

7.7 Afforestation in Degraded site7.7.1 Afforestation in Desert7.7.2 Afforestation in Salt Affected Soil7.7.3 Afforestation in Denuded Hill Slopes7.7.4 Afforestation in Ravine Lands7.7.5 Afforestation in Coastal Shifting Sands7.7.6 Afforestation in Mining Area

7.8 Gene management, Forest Protection and Regeneration

7.9 Natural and Artificial Regeneration of Forest7.9.1 Natural Regeneration7.9.1.1 Natural Regeneration from Seed

7.9.1.2 Natural Regeneration from Vegetative Parts

7.10 Artificial Regeneration7.10.1 Basic Steps in Artificial Regeneration

7.10.2 Artificial Regeneration by the Vegetative Method

7.11 Forest Management to Increase Carbon Density

7.12 SilviculturalManagement

7.13 Forest Tending

7.14 Let Us Sum Up

7.15 Key Words

7.16 Suggested Further Reading/References

7.17 Answers to Check Your Progress

7.1 INTRODUCTIONForests have always been valuable to the human and played an important rolein the history of civilization. Even today, nearly half the global population depend

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ForestryandOther LandUseson wood for cooking, and in many developing countries, nation wood remainsthe primary heating fuel. Forest provide numerous goods and services andmaintain life support systems essential for life on earth. Some of these life supportsystems of significant economic and environmental importance are: (i) supplyof timber, fuelwood, fodder, and a wide range of non-wood products; (ii) naturalhabitat for biodiversity and repository of genetic wealth; (iii) provision ofrecreation and opportunity for ecotourism; (iv) playing an integral part of thewatershed to regulate the water regime, conserve soil, and control floods; and(v) carbon sequestration and carbon sink. In this unit, we endeavour to learnthe mitigation meaures in the forestry and other related land-use; afforestationand reforestation strategies; and silivcultural management practices.

7.2 OBJECTIVESAfter studying this unit, you should be able to:

explain how reducing deforestation and degradation can mitigateclimate change;

describe the afforestation strategies in salt affected soil and coastal shiftingsands;

describe the afforestation strategies in denuded hill slopes and ravine lands;

describe the afforestation strategies in degraded site, mining area and desertregions;

explain gene management, forest protection and regeneration; and

explain forest management to increase carbon sequestration.

7.3 FORESTS AS LAND-USEForests prevent erosion and moderate the availability of water, improvingthe water supply from major watersheds to cities. Forests are habitats forendangered species and other wildlife. They are important for recreationincluding hiking, hunting, bird watching and wildlife viewing. At local andglobal levels, forests may also be significant factors affecting the climate.Planting trees either in the barren land or depleted forest areas haveimmense environmental benefits. Afforestation has potential to meet theincreasing demand of growing population. Further, forest trees are carbonsink and hence can reduce the problem of greenhouse gas emissions.Afforestation is, therefore, a practice that has been advertised by thegovernment and non-government agencies in various countries as a wayto combat the issues of soil erosion, pollution, global warming and climatechange, conservation of biodiversity and overall environmental balance.

7.4 DEFORESTATIONThe term ‘deforestation’ describes the complete long term removal of treecover. According to the United Nations’ Food and Agriculture Organization(FAO), deforestation is the permanent destruction of forests to make theland available for other uses. Deforestation is one of the leading causesof the ecological degradation and has a severe impact on human life and the

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Agriculture, Forestry andOther Land Uses

environment. The loss of forest cover influences the climate and contributes toa loss of biodiversity. In India, massive deforestation has occurred in the lastfew decades for creating industries and infrastructures such as highways, airports,power plants, mining of coal, minerals, metals, etc. The increasing demands forfood and other products also exerted pressure on land that has caused forestland to be utilized for cultivation. This has created ecological imbalances andsevere damage to the Earth. With respect to their vast expanse, the saline-alkali soils are perhaps the most problematic class of the wastelands in thecountry. It has been suggested that these soils offer one of the best possibilitiesfor extending the area under forests.

7.4.1 Causes and Consequences of Deforestation

According to FAO record, the annual deforestation rate in India was 0.6%during the period 1981 to 1990. At the Earth Summit in Rio de Janeiro(1992), the issue linked with deforestation was the leading concern. TheAgenda 21 of the United Nation Conference on Environment andDevelopment asserted that the deforestation is a result of many developmentalactivities, such as the expansion of agricultural areas, growing forest productdemand, improper land use, inadequate land tenure policies and lack ofinformation about and understanding of the value of forests. Economically,deforestation has contributed much more by providing an opportunity forthe society to make positive changes in their life. Unfortunately, the negativeeffect of deforestation is much higher than its benefits.

Conversion of forests to agricultural land to feed growing population isoften cited as the leading cause of deforestation. According to Forest Surveyof India, till now approximately 2.76 Mha of forest land has beenencroached for agriculture. An estimated 300 million people practice slashand burn agriculture which is capable of removing more than 5 lakh haof forests for shifting cultivation annually. In India, this practice is mainlyfollowed in the North-east region and to some extent in Andhra Pradesh,Bihar, and Madhya Pradesh, which contribute to nearly half of the forestclearing annually. The maximum of the area that has undergone deforestationis unsustainable for long-term agricultural use.

Another cause of deforestation is mining operations. Tropical forests arethe location of various deposits of minerals and ores, containing diamonds,oil, aluminium, and gold. The forests are destroyed to extract these materialsfrom the soil. In some circumstances, additional forest logging is performedin the vicinity of mines to expand the accessible place for the storage ofthe created debris and soil. Mining causes soil erosion, the formation ofsinkholes, loss of biodiversity, and contamination of soil, groundwater andsurface water by toxic chemicals released from the mining processes.

Cattle’s ranching is another leading reason for deforestation. The cattleranchers also clear forests to make a scope for grazing cattle. Theuncontrolled and indiscriminate grazing in the forests leads to degradationof forest topsoil and affect natural regeneration of forests. Overgrazingreduces the value, fertility, and biodiversity of the area and is one causeof desertification and soil erosion. Overgrazing is also recognized as a causeof the spread of invasive weeds and non-native plants species.

Dams built for hydroelectric power plants are another reason for deforestation.

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ForestryandOther LandUsesWhen the dams are built, they flood vast areas of forest, destroying the trees,which also breaks the ecological balance of the area. In the deforestation area,floods, droughts, and landslides become more prevalent. The lands, oncedeprived of their forest cover, rapidly degrade in quality, losing their fertilityand arability. The forests are the repositories of invaluable gifts of the natureearth in the form of biodiversity. The destruction of these forest resources mayresult in loss of those species which are still unknown.

Since industrialization and urbanization, forest lands are used to promote theseactivities, which created a harmful effect on the environment and forest ecologicalbalance. Sometimes factories are established after the destruction of the forest.In the process as mentioned above the precious plant, wild animals and rarebirds are destroyed, and the quality of the environment is adversely affected.Supply of raw materials to the forest-based industries is another leading causeof forest destruction in the hilly areas. The over-exploitation of forest for varioustypes of forest-based raw material such as resin and turpentine are alsoresponsible for the destruction of trees in those mountainous regions.

Fuelwood from the unmanaged forest is also a cause of deforestation. Of thetotal fuelwood nearly 85 % is used in the countryside and 15% in urban areas.According to an estimate by Forest Survey of India, the annual demand forfirewood in the country is more than 235 million cubic meters. Thus, fuel woodis also an important factor in deforestation. Frequent fires are also known asone of the leading causes of the destruction of forests in India. Some firescasualties are incidental while the majority of them are deliberate. Accordingto a study conducted by the Forest Survey of India (1996), on an average,53.1% forest vegetation is affected by the fire casualties. Fire casualties createenvironmental pollution, stress and, result in adverse effects on forest ecologyand fatalities in the wildlife population.

7.4.2 Effects of Deforestation on Environment

Deforestation has many negative effects on the environment. The mostdramatic impact is loss of habitat for millions of species. According tonational geographic, 70% of Earth’s land animals and plants live in forests,and many were lost due to deforestation that destroys their habitat. Treeroots anchor the soil, without trees, the soil is free to wash or blow away,which can lead to vegetation growth problems. Eventually, rain washesdown the soil surfaces and erosion take place. Soils never get their fullpotential back. Soil erosion can also lead to silt entering the lakes, streams,and other water sources. This can decrease local water quality and contributeto poor health in populations in the area. Deforestation results in reducedrainfall, increased drought, warmer summer, and colder winter. Moist andfertile land of forests may be converted to deserts due to decreased amountof rainfall and no floods. The soil is exposed to the sun’s heat, soil moisturedries up and gets eroded by wind and water. Loss of forest leads to soilerosion, loss of nutrients and organic matter, and finally, desertificationoccurs which makes the soil of no use. Timber and fuelwood availabilitymay drastically reduce. Forest products like resin, tannin, gums, latex, lacavailability may be affected. Deforestation would result in loss of biodiversityand germplasm having a devastating effect on ecological balance. The loss ofhabitat can lead to species extinction. It also has negative consequences for localpopulations who rely on the animals and plants in the forests for hunting

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and medicine. Deforestation is considered to be one of the contributing factorsto global climate change due to increase in carbon dioxide concentration in theatmosphere.

7.5 MITIGATIONMEASURES: REDUCINGDEFORESTATION AND DEGRADATION

There are several ways of preventing or reducing deforestation. In manyregions of the Earth, reforestation and afforestation are used to achieveenough forest cover and to increase the forested lands. Land skinned ofits tree cover for urban settlements should be urged to plant trees in thevicinity and replace the cut trees. Also, the cutting must be replaced byplanting young trees to replace the older ones that were cut.

For all purposes, where forest products are used, today other materials couldnot be substituted at a larger scale. As long as there is a market for woodproducts, trees will continue to be cut down. Solution may lie in utilisingplant trees in non-forest areas like barren land, marginal lands, communitylands and degraded forest lands. There is a dire need for land reforms soas to address comprehensively the issue of deforestation. Additionally, theforest rights of indigenous people needed to be safeguarded Further,education coupled with training of forest managers and other stakeholderscan greatly aid them to adopt sustainable forest related activities.

A wide range of policy statements, legislative and regulatory measures havebeen established to protect the forests but need to be properly implemented.The policies and laws should be such that they encourage local peopleand institutional participation in forestry management and conservationalong with safeguarding indigenous people’s traditional rights and tenurewith appropriate sharing of benefits. Many formal and informal approachesincluding negotiation, warnings, canceling work orders, notices of violation,fines, arrests and court action can help to prevent deforestation andenvironmental problems from forestry activities.

Check Your Progress 1

Note: i) Use the space given below for your answers.ii) Check your answers with those given at the end of the unit.

1) Write about the economic and environmental importance of forests?

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2) What are the causes of deforestation?

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ForestryandOther LandUses7.6 AFFORESTATIONAfforestation is the conversion from other land uses into the forest, or the increaseof canopy cover to the 10% defined threshold for the forest (FAO 2000).Afforestation is essentially the transformation of land which has not been forestedthrough seeding and planting. Afforestation is an extremely viable option tocontain overuse of forest and also can meet the needs of human beings.

Advantages and Limitations of Afforestation

Afforestation is the best technique to restore the ecological balance of allecosystem. It helps to maintain biodiversity, conservation of soil and waterresources, prevent flood and safeguard of the society. Afforestation has its shareof limitation as well.

Advantages

i) Afforestation provides jobs and employment opportunities for tree planters.Trees provide oxygen and also help to preserve ecological splendor of thelandscape which in turn attracts tourists from all parts of the world.Moreover, there may be additional employments provided if the site wereto become a destination for ecotourism.

ii) With an increase in demand for forest and wood products for theconstruction of infrastructure and forest products. Afforestation can enhancethe supply of timbers and other forest products to meet such increasingdemands.

iii) Trees provide habitats for wildlife; forests are the places of almost everyecosystem being a home, food origin and venue of protection for animalspecies, insect, etc. By just planting more trees we are providing supportand encouraging wildlife and ecosystems to flourish.

iv) Afforestation is useful especially when it comes to protecting the wildlife.According to recent scientific studies, upland forest vegetation tends to affectthe population of birds on neighboring unplanted moorlands. Planting oftrees just restores and maintains the ecological balance of all systems inthe environment.

v) The roots of the trees help bind the soil together, which prevents the processof soil erosion. They significantly reduce the run-off after heavy rains.

vi) Planting of trees in semi-arid areas increases the amount of rainfall. Thisenhances the agricultural practices such as irrigation to carry out efficiently.Also, afforestation acts as a catchment for water and soil conservation.These acts can help to stabilize the climate of afforestation regions.

vii) The process of afforestation also often gets used as a method for riverbanks and ravine lands management, through the course of sustainingriverbanks, as well as acting as an interception of rainwater to go straightinto the river.

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Limitation

The limitation of afforestation is the simple fact of real opportunity cost; theland can no longer be used for agriculture or residential buildings which couldperhaps benefit society through greater outputs of food and a greater supplyof housing.

7.7 AFFORESTATION IN DEGRADED SITE

The aridity, salinity, low-fertility, extremes soil pH, an abundance of poor qualitywaters and fragile land structures make the soil unfit for proper cultivation. Theselands can be allocated for taking up afforestation programs. The afforestationis mainly focused on wastelands, desert, salt-affected soil, ravine lands, denudedhill slopes, and coastal shifting sands, etc. Hard woody tree species are suitableto be grown under these extreme conditions.

7.7.1 Afforestation in Desert

Desert is defined as areas with an average annual precipitation of less than 250millimeters per year. Deserts cover a huge area of the Earth’s land surface (about25%) and can be found in the tropics, at the poles, and in between. Desertsoils are the soils which have almost no water available for soil formation(pedogenesis) and for the growth of mesophytic plants for extended periodsof time. Desert soils form in areas where the demand for water by the atmosphere(evaporation) and plants (transpiration) is much greater than precipitation.Desertification refers to a decline in the biological productivity of arid and semi-arid lands, caused by stress conditions that can be natural or man-made. Theseconditions, if continued for an extended period, lead to ecological and soildegradation. The risk of desertification in the world is critical and is apparentlymoving forward.

Afforestation in the desert is a tough venture because of the arid climate, hightemperature, low rainfall and high wind velocity. Accordingly, a tree in the desertmust be extremely hardy to endure such conditions. Currently, afforestation isdone to stop wind erosion of soil and sand particles, which deposits on thenearby areas. The most commonly grown trees of the arid and semi-arid regionbelong to the genus “Prosopis”. The tree species under this genus like Prosopiscineraria, P. juliflora, P. glandulosa, P. fareta, and P. stephoniane are thewell known to tolerate such stresses better than food crops. The tree speciesProsopis cinerarium is known as “Kandi,” is a famous tree of arid and semi-arid zones of Pakistan and India. The unripe green pods are used as a vegetableand in the preparation of curries and pickles.

The total area of hot desert in India is approximately 31.30 million hectares,and 12.60 million hectares of the total is occupied by moving, and semi-established sand dunes of different degrees and extent mainly in Rajasthan. Seedsfail to germinate in the un-stabilized windblown sand, and often seedlings getburied by drifting sand. Sand dunes keep moving from one place to another.In the area where sand has become stabilized, the soil may be fertile but isusually associated with accumulation of lime nodules. Plantation of shelterbeltsshould form a part of desert afforestation. They reduce the wind velocity andthus check the shifting of dunes on the leeward side.

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ForestryandOther LandUsesAccording to Central Arid Zone Research Institute, Jodhpur (Anon, 1969) ithas been found that in Banner (Rajasthan) where rainfall is only 200 mm. Acaciatortilis and Callignonem polygnoides have proved successful. Acacia senegal,A. aneura, Eucalyputs camaldulensis, E. occidentale (from Israel), E. oleosa(Perth, N. Australia) have given encouraging results. Among grasses, Saccharummunja, Panicum antidotale, P. turgidum, Cenchrus ciliaris, C. latharicus,Eleusine spp., Elionurus hirsutus and Pennisetum spp., have been foundsuccessful in these areas.

7.7.2 Afforestation in Salt Affected Soil

Soluble salts of sodium, calcium, magnesium, potassium of chloride and sulfateare present in saline soils, which cover the land in the form of a white layer.It is also known as reh or kallar. The salt-affected soils in India (Table 7.1),which is currently occupying an area of 7.04 Mha, could be employed asalternate sites for afforestation. From the management point of view, these soilshave been grouped into two categories (a) Saline soils, (b) Alkali (sodic) soils.

Table 7.1: Salt-affected soils in India

Broad groups States Approximatearea (Mha)

Coastal salt-affected soils

a) Coastal salt-affected soilsof Gujarat Gujarat 0.714

b) Deltaic coastal salt-affected West Bengal, Orissa, 1.394soils in the humid regions Andhra Pradesh &

Tamil Nadu

(c) Acidic salt affected soils Kerala 0.016

Salt-affected soils of the Karnataka, Madhya 1.420medium and deep black soils Pradesh, Andhra

Pradesh & Maharashtra

Salt-affected soils of the arid Gujarat, Rajasthan,and semiarid regions Punjab, Haryana &

Uttar Pradesh 1.000

Alkali soils of the Indo- Haryana, Punjab,gangetic plains Uttar Pradesh, Bihar,

Rajasthan &Madhya Pradesh 2.500

Total area under salt 7.044affected soils

(Source: Gill et al., 1997)

In saline soils, the twin problems are presence of salt and non-availability ofquality irrigation water. Under these conditions, the focus should be on the choiceof tree species, planting method, and silvicultural practices. Tree species suitablefor afforestation in salt affected soils are Acacia nilotica, Acacia catechu,

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Acacia pennatuia, Acacia saligna, Acacia fernesiana, Cassia fistula,Casuarina equisetifolia, Feronia limonia, etc. Further, subsurface planting andfurrow irrigation method is found to be suitable for afforestation in problem soils.In salt affected soils, plantation for fuel wood is more preferred.

7.7.3 Afforestation in Denuded Hill Slopes

The hills have been denuded by uncontrolled fellings associated with excessivegrazing and frequent fires. In some areas due to the growth of grasses, theerosion has been less damaging. However, in most regions the surface soil hasbeen eroded. In many areas, even subsoil has disappeared, leaving practicallyno soil material. These soils are generally poor in moisture and nutrients. Theseadverse conditions make the afforestation operation difficult on denuded hillslopes.

Soil preparation in denuded hill slopes includes formation of contour trenches,patches, and pits. The contour trenching mainly aimed at preventing soil erosionand also it helps in soil and water conservation. When the slopes are steeper,digging of trenches may not be possible and, in such cases, preparation of pitsfor planting or preparation of ‘thalis’ for sowing may be adopted. Maintenanceof regular spacing may not be possible in many areas, particularly on steeperslopes and badly eroded sites. In such areas, sowing or planting is carried outin the best available locations.

The choice of tree species depends on many factors like local species, growthhabit of trees, etc. Examples of trees suited are: (i). pine trees in moist subtropicalarea (ii). Acacia modesta, A. catechu, etc. in dry subtropical area (iii). Pinuswallchina and Deodar are suited for Temperate zone. In the dry areas of North-West India, species such as Acacia modesta, A. catechu, Prosopis chilensis,etc.,and in the peninsular region, Eucalyptus tereticornis, Anacardium occidentale,Acacia auriculiformis, Cassia siamea, Albizia lebbeck, etc., have beensuccessful.

7.7.4 Afforestation in Ravine Lands

Land degradation by ravines and gullies is widespread in India. It is reportedthat about 4 million ha is affected by ravine topography. Ravines are a networkof deep gullies. The whole land mass is cut by some deep gullies. These landsoccupy about four million hectares mainly on the banks of the rivers Yamuna,Chambal, Mahi, and Betwa, which lie in the States of Uttar Pradesh, Rajasthan,Gujarat and Madhya Pradesh.

Ravine formation begins along river sides and encroaches upon the catchmentarea by headward growth. Active gully systems commonly develop inunconsolidated materials due to changing patterns of land use and associatedchange in catchments hydrology. The ravines are characterized by the absenceof vegetation of any type. The run-off is maximum; slopes are steep, and gulliesare of varying depth from a few meters to 100 meters or more.

Ravine afforestation has to be carried out on catchments basis with otheroperations of soil and water conservation. In order to achieve better results,the afforestation of ravines may be accompanied by proper management ofagricultural lands. Prevention of erosion by making of the gullies of the slopes

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ForestryandOther LandUsesgentle and by diverting the surface flow is an essential prerequisite for anysuccessful afforestation program. The gullies have to be plugged with suitablemechanical measures to conserve soil and moisture. The slopy areas of theravines have to be covered with grasses, trees, etc., to avoid further deterioration.

The species which have been grown successfully in India are Eucalyptus spp.,Dalbergia sissoo, Albizia lebbeck, Pongamia glabra, Acacia catechu,Dendrocalamus strictus, Acacia nilotica, Ailanthus excelsa, Prosopis chilensis,etc. Afforestation by nursery raised seedlings is the most successful method butit needs more time, expenditure, great care, and skill. Direct seeding is alsorecommended as it is a quicker and cost effective method of afforestation. WhileAcacia catechu, Pongamia pinnata, Dalbergia sissoo, etc., are suitable treespecies for afforestation in Ravine Lands, Terminalia arjuna, Acacia leucophloea,Prosopis spicigera, etc., are suitable for clayey soils. Grasses such as Alpudamutica, Aristida royleana, Cenchrus ciliaris, Dichanthium annulatum andHeteropogon contortus have been found fruitful and economical in stabilizingravines.

7.7.5 Afforestation in Coastal Shifting Sands

Coastal shifting sands exist normally along sea coast. The tides are responsiblefor deposition of sand in the sea coasts. The sands are vulnerable to shiftingdue to the impact of prevailing wind. Also, these coastal sands do not holdmoisture. Casuarina has been found to be the best species in these regionsdue to its fast growing habit and hardy nature. Pongamia pinnata, Eucalyptus,etc., are other species grown in the coastal regions. As regards the inland sands,tree species like Acacia catechu, Dalbergia sissoo,Albizzia procera, Acaciaarabica are preferred.

7.7.6 Afforestation in Mining Area

The nature of mining processes has a potential negative impact on the environmentboth during the mining operations and for years after the mine is closed. Thisimpact has led to most of the world’s nations adopting regulations to moderatethe adverse effects of mining operations. Open-cast mining for several minerals,e.g., coals, bauxite, limestone, slate, etc., is quite common. Before growingplantation, it is necessary to level the area with the help of dozers as it is easierto make pits in leveled areas. Pits of 60 cm3 are usually dug at a spacing of2 x 2 m. The pits should be filled with fertile soil from nearby forests. Theaddition of farmyard manure at the rate of 0.5 kg/pit has been found useful.Some results confirmed the addition of forest soil is necessary for mycorrhizalinoculation required in pines and other broad-leaved species.

Several species have been tried in afforestation of these locations. The specieswhich have shown success are Acacia auriculiformis, Dalbergia sissoo,Eucalyptus camaldulensis, Grevillea robusta, G. pteridifolia, Pinus caribaea,Albizia lebbeck, Prosopis chilensis and Cassia siamea. The species such asGrevillea pteridifolia, Acacia auriculiformis, Pinus caribaea and Eucalyptuscamaldulensis have shown a faster growth rate than other species grown inthe area.

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Agriculture, Forestry andOther Land Uses 7.8 GENE MANAGEMENT, FOREST

PROTECTION AND REGENERATIONConsidering the fundamental importance of genetic diversity to the continuedadaptability, health, and long-term productivity of tree populations, a loss ofgenetic diversity could be a serious threat to forest ecosystems and the manyproducts and services they provide to all life forms. Keeping a diversity of treespecies within and among stands can be significant in the maintenance of thebiodiversity associated with forest ecosystems. Reforestation plan helps to ensurevalues such as biodiversity, stocking of ecologically suitable and desirable mixof species, maintaining or enhancing genetic diversity.

Forest regeneration is the act of renewing tree stand by establishing young treesnaturally or artificially, often immediately after the previous stand or forest hasbeen removed. It includes practices such as changes in tree plant density byregeneration, enrichment planting, or changes in tree provenance or tree species.In nature flowering, fruiting and fruit ripening behaviour of tree species are notcommon, even the seed-bearing in trees species is not regular every year. So,it is essential to know the behaviour of trees species, exact timing of floweringand enough quality seed produced. Seed quality involves both genetic stabilityand the physiological quality of seeds.

The regeneration of tree depends on the quality propagules (planting material)which in turn largely depends on the nurseries and nursery activities. Selectionof quality seed and propagules, and adaptation of appropriate plantationtechniques can contribute significantly to the success of forest regeneration andestablishment by ensuring better survival percent of seedlings and plantingmaterials.

7.9 NATURAL AND ARTIFICIALREGENERATION OF FOREST

The regeneration has been defined in various ways by several authors. Accordingto Dwivedi (1992), “regeneration is defined as the renewal of forest crop bynatural or artificial means”. The words propagation and reproduction are alsoused as synonyms. However, the terms regeneration is more widely used.Regeneration method is a procedure by which a stand is established or renewedusing natural or artificial reproduction. The following methods are extensivelyused for forest regeneration.

7.9.1 Natural Regeneration

Natural regeneration is indeed renewing of a forest either through self-sown seedor by vegetative parts. It is a primary process on which a forester can relyto influence the dynamics of forest stands and to preserve the geneticcharacteristics of a local tree population. The following methods are used fornatural regeneration of forest.

7.9.1.1 Natural Rgeneration from Seed

Natural regeneration by seed is one of the standard methods of regenerationof forest. The natural regeneration from seed squarely depends on seedcharacteristics like production, dispersal, germination and seedling establishment.The crop established through a seed is called seedling crop and the forest

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ForestryandOther LandUsesconstituting such seedling crops is called high forest.

The success of natural regeneration from seed depends on the adequateproduction of viable seeds. Further, the viable seed production depends on thetype of tree species, climatic conditions, pest and disease attack, etc. It isreported that seed dispersal provides impetus for the survival of seedling asthey are away from the competition of parent plant. The seed originated bythe trees is dispersed by the agency of wind, water, gravity, birds and animals.

Though insects, birds and rodents destroy a lot of seeds, but a small proportion(generally much less than 10%) survive to germinate provided they are depositedon suitable sites where the optimal condition exists. When the seed falls onthe ground just near the tree or away due to various dispersal agents, the seedmay germinate. The tree species have a maximum and minimum temperaturefor their seed germination, relatively above or below of which germination doesnot take place. Most tree species seeds germinate in the dark, but a few speciesfor example Cassia fistula or Albizzia procera do require light to germinate.Germination is a crucial stage in the growth of tree seedlings. As a tree seedmoves from an inactive to an active stage, delicate seedling roots must emergeand establish in the soil before a young shoot appears above ground.

Inspite of favourable germination, the seedlings die due to frost and other naturalcalamities. Besides this, a large number pest and disease and non-insect pestsattack the seedlings and also causing mortality. Various factors such as thedevelopment of roots, soil conditions (moisture, aeration, and nutrients), slasherosion, infirmity of grasses and competing weeds and composition of the treecrop affect the establishment process. Climatic factors (light, high or lowtemperatures, rainfall), grazing, browsing, and wildfire also affect successfulestablishment of newly germinated seedlings.

7.9.1.2 Natural Regeneration from Vegetative Parts

Natural regeneration of tree stands by vegetative part i.e. coppice is one ofthe important methods in forestry. Coppice is defined “as shoot arising froman adventitious bud at the base of a woody plant that has been cut near theground or burnt back.” Crop from coppice is called coopice crop and similarlythe forest developed from coppice crop is called as coppice forest. Coppicingcomprises of cutting young tree stems down to a base or less from groundlevel to encourage new shoots to form. Coppicing should be performed in thewinter, or when the tree or shrub enters its dormant period. New shoots growthe following spring. Coppicing produces multi-stemmed growth rather of a single,primary trunk. In a forest setting, trees are coppiced in rotational segments withtrees in varying stages. This way, wood is regularly available for harvest.

Coppice in a forest stands composed of stools that produce coppice shootswhich form the major part of the crop. The stand may be simple coppice orcoppice with standards. In simple coppice, the crop is clear felled to give even-aged stands which may be of a single species such as hazel or sweet chestnut.Coppice with standards is a system in which selected stems are retained ateach felling to form an uneven-aged overstorey of standards which are removedselectively by a rotation which is a multiple of the coppice cycle.

A. Root sucker

Shoots emerging from the roots of woody plants are called root suckers. Thenatural regeneration by root suckers is not practiced on a large scale. However,

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this method is practiced locally in some species, e.g., Dalbergia sissoo,Boswellia serrata, Diospyros melonxylon, etc.

B. Seedling Coppice

The shoots that arise from the base of seedlings which have been cut or burntare called seedling coppice. Some species may remain in the seedling state forseveral years for no apparent reason, their annual stems dying back year afteryear while the rootstock survives.

C. Stool Coppice

Stool coppice arise either from the stool or a living stump of a tree. In thiscase, regeneration is made possible through the emergence of shoots from theadventitious buds of the stump. Further, the shoots are found to arise eitherfrom the top of the stump or from the base of the stump. The coppicing powerof the trees also depends on upon their age, vigour, the season of cutting andsite conditions. It would thus realize that one can depend only on species, whichhas a strong coppicing power.

D. Pollarding

Pollard is defined as a tree whose stem has been cut off to get a flush ofshoots usually above the height to which the browsing animal can reach (Anon.1966). It is an operation in which the stem of a tree is cut off at a heightusually above 1.5 or 2 m with the objective of obtaining a bunch of new shootsi.e. Salix spp. (Kashmir Valley), Hardwickia binata (Andhra Pradesh), Grewiaoptiva (Himalayan hills), and Morus alba mostly pollarded in plains areas. Thepollarding technique is practiced to encourage lateral branch growth and toregulate the height of a tree or shrub. It should also be done at the plant’sdormant period and should include cutting a tree stem to approximately 8 to10 feet above ground level. Repeated pollarding encourages a slightly swollentrunk, with many new sides and top shoots. Pollarding is used in urbanenvironments to prevent trees from damaging service lines and sewers. In apasture setting, it allows keeping the tree in a perpetual sapling state, whichextends the life of the tree because diseases take the time to infect the woodat that height.

7.10 ARTIFICIALREGENERATIONAccording to Dwivedi (1992), artificial regeneration is defined as “the renewalof a forest crop by sowing, planting or other artificial means”. The wordplantation is also used as a synonym for the artificially regenerated crop. Theplantation is defined as “a forest crop raised artificially either by sowingor planting”.

7.10.1 Basic Steps in Artificial RegenerationChoice of Species: The choice of species is very important in artificial forestregeneration and establishment. Therefore, before choosing the tree species, thepurpose of growing the trees has to be specified.

Choice of the method: The success of artificial regeneration depends on, toa great extent upon the choice of method. There are mainly two methods ofthis regeneration, viz. (i) Sowing and (ii) Planting.

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ForestryandOther LandUsesSite Selection: The selection of site is also a crucial factor in artificialregeneration. Several factors like ground cover, man-power affect the sitepreparation.

7.10.2 Artificial Regeneration by the Vegetative Method

Seedlings, cuttings, layering, rhizomes, suckers, offsets, bulbs, corms are usedfor vegetative propagation. Cuttings include stem cuttings, root cuttings, andstumps.


Note: i) Use the space given below for your answers.ii) Check your answers with those given at the end of the unit.

1) What is afforestation? What are the tree species grown in desert region?

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2) What is regeneration? What is the difference between the natural andartificial regeneration?

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7.11 FOREST MANAGEMENT TO INCREASECARBON DENSITY

Terrestrial carbon sequestration is viewed as a potential area for climate changemitigation, as the carbon sequestration enables sequestering of atmosphericcarbon dioxide through the process of photosynthesis. In fact, the sink of carbonsequestration in forests and wood products helps to offset sources of carbondioxide to the atmosphere, such as deforestation, forest fires, and fossil fuelemissions (Shah et al. 2009; USDA, 2018). Sustainable forestry practices inaddition to increasing the ability of forests to sequester atmospheric carbondioxide, enhance ecosystem services. Harvesting and regenerating forests canalso result in net carbon sequestration in wood products and new forest growth.Broad categories of forestry activities that can contribute to increasing carbonstocks or reducing emissions include (Sample et al. 2015; http://www.pinchot.org/PDFs/IntegratingForestCarbonManagement_web.pdf):

i) “Increase forest coverage: Reduce deforestation; promptly reforestafter timber harvest or fire; increase afforestation of marginal andpasture land.

ii) Increase carbon stocks: Use forest management to maintain orincrease carbon storage in live trees, reduce carbon loss fromdisturbance, and encourage forest regrowth as quickly as possible afterharvest and disturbance.

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iii) Increase the use of wood bioenergy: Increase the efficient andsustainable use of wood biomass in place of fossil fuels in energyproduction”.

7.12 SILVICULTURALMANAGEMENTThe growing of trees is called silviculture. People have long practiced silviculture,much as they have grown crops, but forestry developed into a science-basedactivity and into what we today consider a profession in the late 19th and early20th centuries. In simple words, silviculture is the growing and tending standsof trees. Accordingly, without exaggeration, silviculture is the real art of forest.According to David M. Smith, (1986), “The silvicultural system consists of thevarious treatments that may be applied to forest stands to maintain and enhancetheir utility for any purpose”. Silviculture also ensures the long-term continuityof essential ecologic functions, and the health and productivity of forestedecosystems (Ralph Nyland, 1996).

There is tremendous scope for silviculture in India because of the needs ofgrowing population i.e. shortage of fuel, fodder, and quality timbers, etc.Silviculture has vast scope in meeting these demands through multipurpose treespecies. We are also facing many environmental problems and impact of climatechange in some part of the country. Silviculture has the scope to combat theadverse effects of climate change through carbon sequestration and directlyreduce the buildup of greenhouse gases in the atmosphere. This system permitsthe growing suitable tree species, provides the rawmaterial for cottage industries,efficient utilization of resources, helps in maintaining ecological balance, soil andwater conservation, soil improvement and helps in meeting various needs ofgrowing population.

7.13 FOREST TENDINGForest tending is a core component in silviculture. In a forest, competition amongtrees can be increased with increasing age. In order to obtain the highest yield,the competition among the trees can be optimally managed by reducing thenumber of stems per unit area with the progress of the age. These activitiescan be covered under the tending operations. Tending is defined as an activitycarried out for the benefit of a forest crop at any stage of its life betweenthe seedling and the mature stages. This operation prepares the plantation forfuture management actions by removing some less-favored trees. Tending canpotentially improve the health of a forest.

Forest tending facilitates future management activities by providing access tothe provision of frameworks and focusing supervision on those trees speciesthat will benefit from it the utmost. Width and growth of selected stems willincrease due to reduced competition. For the establishment of the regenerationand subsequent development of the forest crop up to harvesting, severaloperations are carried out. These operations are conducted in the forest atvarious stages of growth to provide a healthy environment for their development.These transactions are called tending operations which includes weeding,cleaning, thinning, improvement felling, pruning and climber cutting. Removal ofall trees from a chosen area (for harvesting) is called clear felling. Shelterwoodsystem is the practice of cutting dead and less desirable trees first, and latercutting mature trees. Clear felling on a large scale is neither necessary nor

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ForestryandOther LandUsesdesirable for the best timber production. However, where the ground is levelor slightly sloped, where rainfall is moderate, and where the desirable speciesrequire open areas for growth, clear felling on an appropriate spatial scale maybe a useful way to regenerate desirable species. The key here is that clearfelling is neither all good nor all bad for timber production or forest ecosystems.Its use must be evaluated on a case-by-case basis, taking into account the sizeof cuts, the environment, and the available species of trees.

The seed-tree method is the removal of the old stand in one harvest entry,except for a small number of trees left singly, in small groups, or narrowstrips, as a source of seed for natural regeneration. This method mimicsa large-scale disturbance, in which a few mature trees are left per acre.The seed tree method is most appropriate to species that are shade intolerant,good seed producers, resistant to wind throw and breakage and havecomparatively light seeds easily carried by the wind (Gray, 1990). Avariation of the method is a seed-tree cut with reserves.

If the landowner wants a more or less continuous harvest from a particularstand or location in the woodlot, the selection system should be considered.Selection cutting provides a regular harvest of trees from several age classeswithout ever removing the entire canopy. It is often favored by woodlotowners who do not want to clear-cut. Selection cutting removes poor qualitymature and immature trees and provides space and seedbed conditions forthe establishment and development of new trees. As in a shelterwood, thebest trees are left for seed and shelter. Stand tending and harvesting aredone at the same time. It encourages the development and maintenanceof several age classes in the stand. The most common approaches toselection harvesting are single tree selection and group selection.

Often, operations are a combination of both. Selection harvesting is notappropriate for all stands. For example, stands made up of short-livedspecies that do not grow well in partial shade and poor quality trees maybenefit more from a clear-cut that is correctly regenerated. Also, even-agedstands containing young, healthy, good quality, long-lived species (i.e. redspruce) are more suited to a commercial thinning) than a selection harvest.However, these stands may become more suitable as they mature. Althoughit is an uneven-aged system selection cutting can also be used to makean even-aged stand uneven-aged. If not properly done, selection harvestingcan turn into “high-grading” or selective cutting.

In order to ensure continual harvesting of a stand, timber should not be cutfaster than it can be grown. For example, if a stand increases in volume by5.5 cubic meters per hectare per year (one cord per acre per year), you maychoose either to harvest this amount every year or to cut ten cords per acreevery ten years from that stand. If the timber is cut faster than it is grown,the mature usable timber will eventually be used up. If, however, the standcontains a high proportion of over mature trees, more timber can be cut duringsome cuts to use allmature timber and gradually develop the younger age classes.On the other hand, if the growth rate is undercut, eventually there will be anexcess of mature to over mature trees in the stand and trees will die. Periodicalexamining and cutting accordingly should ensure cutting balances growth.

7.14 LET US SUM UP

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In this unit, you have learnt, how reducing deforestation and degradation canaid in mitigating climate change. Further, afforestation and reforestation areconsidered as an important mitigation strategy as they aid in terrestrial carbonsequestration. Afforestation strategies in different areas like salt affected soil;coastal shifting sands; denuded hill slopes; ravine lands; degraded site; miningarea; desert regions were discussed explicitly. In addition, you were familiarizedthrough this unit with fundamentals of forest protection, regeneration, andsilviculturalmanagement.

7.15 KEYWORDSDeforestation : Deforestation is the permanent destruction of forests to

make the land available for other uses.

Reforestation : Planting of forests on lands that have previously containedforests but that have been converted to some other use.

Coppice : Coppice is defined as shoot arising from an adventitiousbud at the base of a woody plant that has been cut nearthe ground or burnt back.

7.16 SUGGESTED FURTHER READING/REFERENCES

Anon. (1996) Appendix I-Framework for the global forest resourceassessment 2000. In: Nyyssönen, Aarne; Ahti, Anne, eds. Proceedings, FAO/ECE meeting of experts on Global Forest Resource Assessment; 10-14 June1996; Kotka, Finland. Research Papers 620. Helsinki, Finland: FinnishForest Research Inst.; 106.

Anon. (1996) Monitoring of water table and drainage trial and demonstration,Groundwater Board, Bikaner.

Dwivedi A P. (1992) Agroforestry: Principles and Practices; Oxford & IBHpublishing company. Pp -365.

FAO (2000) Definitions of forest change processes, www.fao.org/docrep/006/ad665e/ad665e04.htm.

Gill H S Abrol I P and Gupta R K. (1997). Afforestation of salt affectedsoils. In. Technologies for wasteland development. I.P Abrol and V.V.Dhruva Narayana (ed.). ICAR, New Delhi, pp 355-380.

Gupta, Raj K., Tomar, O.S., and Minhas, P.S., (1995). Managing Salty Soilsand Waters for Afforrestation. CSSRI Bulletin No. 7/95, Central SoilSalinity Research Institute, Karnal, p. 23 Published by : The Director CentralSoil Salinity Research Institute Karnal (INOlA) Telphone : Telex: SSRI-IN Fax: E. Mail: Printed at: National Printers, 20/3, West Patel Nagar, NewDelhi-l10008.

https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-AnnexII_FINAL.pdf

Ralph N. (1996) Silviculture concepts and applications. https://www.for.gov.bc.ca/hfd/pubs/ ssintroworkbook/meansilv.htm.

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ForestryandOther LandUsesSample AV, Birdsey R, Houghton RA, Swanston C, Hollinger D, DockryM, Bettinger P (2015). Forest Carbon Conservation and Management:Integration with Sustainable Forest Management for Multiple ResourceValues and Ecosystem Services.http://www.pinchot.org/PDFs/IntegratingForestCarbonManagement_web.pdf.

Shah, S., Venkatramanan, V. and Shah, V.K. (2009). Carbon sequestrationactivities in the forest: strategies and challenges. Indian Journal of forestry,Vol. 32(4): 533-536. ISSN: 0971-9431

Smith DM (1986) The practice of silviculture, 8th ed. John Wiley and Sons,New York.

USDA (2018) Carbon sequestration, USDA forest service, available at:https://www.fs.fed.us/ecosystemservices/carbon.shtml.

7.17 ANSWERS TO CHECK YOUR PROGRESSCheck Your Progress 1

1. Some of the life support systems of significant economic andenvironmental importance attributed to the forests are: (i) supply oftimber, fuelwood, fodder, and a wide range of non-wood products; (ii)natural habitat for biodiversity and repository of genetic wealth; (iii)provision of recreation and opportunity for ecotourism; (iv) playingan integral part of the watershed to regulate the water regime, conservesoil, and control floods; and (v) carbon sequestration and carbon sink.

2. The causes of deforestation are expansion of agricultural areas, growingforest product demand, improper land use, inadequate land tenurepolicies and lack of information about and understanding of the valueof forests.


1. Afforestation is the conversion from other land uses into the forest,or the increase of canopy cover to the 10% defined threshold for theforest. The tree species commonly grown in desert environment areProsopis cineraria, P. juliflora, P. glandulosa, P. fareta, and P.stephoniane.

2. Regeneration is defined as the renewal of forest crop by natural or artificialmeans. Regeneration method is a procedure by which a stand is establishedor renewed using natural or artificial reproduction. Natural regeneration isrenewing of a forest either through self-sown seed or by vegetative parts.It is a primary process on which a forester can rely to influence the dynamicsof forest stands and to preserve the genetic characteristics of a local treepopulation. On the other hand, artificial regeneration is defined as “therenewal of a forest crop by sowing, planting or other artificial means”.

UNIT 7 FORESTRY AND OTHER LAND USES - eGyanKosh

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