Soil texture and soil colour

By kamal bhusal on Saturday, March 20, 2010 3:38 AM , 1 Comment

Soil texture and soil colour Soil texture refers to the relative proportion of sand, silt and clay size particles in a sample of soil. Clay size particles are the smallest being less than 0.002 mm and 0.5 mm in size. The largest particle is sand with diameters between 0.05 to 2.00mm for very coarse sand. Soil that are dominates by larger particles are referred to as coarse textured soils. Soil scientists’ group in to:


Soil texture classes:

The sides of the soil texture triangle are scaled for the percentages on the left side of the triangle are read from left to right across the triangle. Silt runs from to the bottom along the right side and is read from the upper right to lower left. The percentage of sand increases from right to the left along the base of the triangle. Sand is read from the lower right towards the upper left portion of the triangle. The boundaries of the soil texture classes are highlighted in blue. The intersection of the three sizes on the triangle gives the texture class. For instance, if you have soil with 20% clay, 60% silt, and 20% sand it falls in the “SILT LOAM” class.

Soil texture effects many other properties like structure, chemistry, and most notably, soil porosity, and permeability. Soil porosity refers to the amount of pore, or the open spaces between soil particles. Pores are created by the contacts made between irregular shaped soil particles. Fine textured soil has more pore space than coarse textured because you can pack more small particles into a unit volume than larger ones. More particles in a unit volume create more contacts between the irregular shaped surfaces and hence more pore space. As a result, fine texture clay soils hold more water then coarse textured sandy soils. Permeability is the degree of connectivity between soil pores. A highly permeable soil is one in which water runs through it quite readily. Coarse textured soils tend to have large, well-connected pore spaces and hence high permeability.
Soil types
1. Loam: When rubbed between the thumb and fingers, approximately equal amount of sand, silt and clay is felt. Makes a weak ribbon (less than 2.5cm long).

2. Sandy loam: Varies from very fine loam to very coarse. Feels quite sandy or, gritty, but contains some silt and a small amount of clay. The amount of silt and clay is sufficient to hold the soil together when moist. Makes a weak ribbon(less than 2.5cm long).

3. Silt loam: Silt is the dominant particle in silt loam, which feels quite smooth or floury when rubbed between the thumb and fingers. Makes a weak ribbon (less than 2.5cm long).

4. Silty clay loam: Noticeable amounts of both silt and clay are present. Makes a medium ribbon (2.5 to 5cm long).

5. Clay loam: Clay dominates a clay loam, which is smooth when dry and silky when wet. Silt and sand are usually present in noticeable amounts in this texture of soil, but are overshadowed by clay. Makes a medium ribbon (2.5 to 5cm long).

Soil Colour

Surface soil colours vary from almost white, through shades of brown and gray, to black. Light colours indicate a low organic matter content and dark colours can indicate a high content. Light or pale colours on the surface soil are frequently associated with relatively coarse texture, highly leached conditions and high annual temperature. Dark colours may result from high water table conditions (poor drainage), low annual temperature, or other conditions that induce high organic matter content and, at the same time, slow the oxidation of organic materials. However, soil coloration may be due to the colours imparted by parent materials. Shades of red or yellow, particularly where associated with relatively fine textures, usually indicate that subsoil material has been incorporated in the surface layer.

Subsoil colours, in general, are indications of air, water, and soil relationships and the degree of oxidation of certain minerals in the soil. Red and brown subsoil colours indicate relatively free movement of air and water allowed by the soil. If these or other bright colours persist throughout the subsoil, aeration is favourable. Some subsoil that are mottled (have mixed colours), especially in shades of red and brown, are also well-aerated.

Yellow-coloured sub soils usually indicate some drainage impediment. Most mottled sub soils, especially those where gray predominates, have too much water and too little air (oxygen) much of the time. The red-to-brown colour of subsoil comes from iron coatings under well-aerated conditions. In wet soils with low oxygen levels, the iron coatings are chemically and biologically removed, and the gray colour of background soil minerals shows.

SELECTION SYSTEM

By kamal bhusal 3:28 AM , 1 Comment

SELECTION SYSTEM

Selection system is defined as a silvicultural system in which felling and regeneration are distributes over the whole of the area and the resultant crop is so uneven aged that trees of all ages are found nixed together over every part of the area.

Basic feature

• Felling distributed over the whole area.
• Resultant crops are completely uneven aged.
• The regeneration operations are carried out the life of the crop and thinning are done simultaneously for improving the growth and form of the trees.

Pattern of felling

• Selection system follows nature in respect of its pattern of felling.
• Scattered single mature trees are selected all over the area and felled to enable regeneration to replace them.
• Regeneration appears in small groups because of periodicity in seed years and age classes are found in small groups.
• Felling of scattered trees all over the area of a forest is possible when the area is small.
• In large area forest is divided into coupes which create certain interval in felling of specific area know as felling cycle.
• Felling cycle is defined as the time that elapses between successive main felling on the same area.
• The length of the felling cycle affects the silviculture of species, exploitation of forests and the nature of crop produced.
• Example –felling of 2% of growing stock in 10 years rotation would result removal of 20% of the growing stock in the coupe.
• Base on felling system it can be divided into two categories:

1. Ideal selection system- selection from whole area each year.
2. Periodic selection system –selection carried out over only a part of the forest each year.

Conduct of felling

1. Dead, dying, diseased, decay and deformed.
2. Undesirable species.
3. Immature tree to balance different age class.
4. Mature tree(above exploitable diameter)

Mode of regeneration:

Natural regeneration, artificial regeneration has to be accepted in some cases.

Tending
Weeding and clearing
Character of the crop produced:
Absolutely uneven aged

Advantages of selection system

1. Full use of site factors
2. Conserves soil and moisture to the fullest extent possible
3. Most resistant to injuries by insect pests and adverse climatic factors
4. Prevent invasion of grass and weeds.
5. Sufficient seed bearers for natural regeneration.
6. Produce more growing stock and large size tree per unit area.
7. Best system of producing large size tree.
8. Forest is superior biologically as well as in its aesthetic and scenic values.

Disadvantages of selection system

1. Considerable skill is required for regeneration felling
2. Cost of logging and extraction is higher
3. Felling, logging and extraction results in damage to the young crop
4. Quality of young crop might be low
5. Difficult to control grazing and fire in regeneration area
6. Success or failure of regeneration is difficult to assess.
7. Growing stock progressively degenerates with every felling

Condition of application

1. Topography
2. Catchments area
3. Low accessible area
4. Market requirement
5. Silvicultural consideration

Application
This is very common and traditional practice of forest management.

Symbiotic and Allelopathic Relationship in Agroforestry:

By kamal bhusal on Friday, March 19, 2010 3:16 AM , 3 Comments

Symbiotic and Allelopathic Relationship in Agroforestry:Symbiotic Relationship:

Much research in agroforestry systems is concerned with increasing the biological input of nutrients to trees and to the crops grown concurrently or consecutively or consecutively with them and with determining how and in what quantities these nutrients become available. The exchange of nutrients among the plants of the agroforestry system results largely from the activity of appropriate soil microorganisms. Associative or symbiotic microorganisms are responsible for nitrogen input and for the availability of other minerals, especially phosphorous, in the ecosystem. Other bacteria make available the nutrients of dead and decaying plants for uptake by the root systems of crop species. Symbiotic microorganisms like Rhizobium and Frankia have potential roles of nitrogen fixation, plant growth regulation, phosphate solubilization and concerned with nutrient transformations of decaying plant material.

The important nitrogen-fixing symbioses are:-1) those between many legume trees species and Rhizobium or Bradyrhizobium and 2) those between Frankia and woody species within the eight non leguminous plant families (so called acinorhizal plants that are nodulated by the nitrogen-fixing actinomycete. For temperature and warm temperate conditions, the most important of the Frankia associations are with Alnus (Betulaceae) or Elaeagnus and Hippophae (Elaeagnaceae), and in the tropics and subtropics, with members of the Casuarinaceae. The most promising candidates for agroforestry are the Casuarina and Allocasuarina genera.

Allelopatic Relationship:

Interference occurs when one plant species fails to germinate, growth more slowly, shows symptoms of damage, or does not survive in the presence of another plant species. Interference can result from competition, allelopathy, or other indirect influences. Competition is the phenomenon by which one plant removes limited resources (such as light, water, or nutrients) from the environment, thereby reducing the survival or growth of a neighboring plant. Allelopathy is the phenomenon in which a plant or microorganisms releases a natural product into the environment that subsequently reduces or enhances the survival or growth of neighboring plants.

Agroforestry intentionally combines woody perennials with agricultural crops or pasture plants in variety of spatial or temporal arrangements, thus the choice of species combinations may dramatically influencing the productivity and ultimate success of some agroforestry systems. The challenge in plant interference work is identifying which of trees various factors because the associated plant response. Allelochemicals originating in foliage teachings, root products, or mulches of crops or woody plants may result in reduced productivity or death of companion plants.
The concept of allopathy is at least 2,000 years old, though the team was not coined until 1973(Wills, 1985). During the past 30 years there has been a significant effort to understand the role of allelopathy in ecological processes.
Because agroforestry is a relatively new field, little work has been conducted on species compatibility (Wood, 1988). Some species currently used in agroforestry systems reportedly have allelopathic interference from Eucalyptus foliage leaching and volatiles and plant residues has been described. Also, residual mulches of Luceaena lecucocephala reportedly have allelopathic properties.

Alleopathy and intercropping: Allelopathy interference can result form natural products in intercrop foliage leaching, root products, and volatiles. There are four ways in which these chemicals are released into the environment.
1) Leaching: - Leaching is the removal of substance from plants by aqueous solutions such as rain, dew, and fog. Radioisotope labeling of plant tissue before leaching has shown that large quantities of both inorganic elements and may classes of organic natural products are leached from plant tissue.

2) Root Exudation: - Root exudation is the release of substances into the surrounding medium by healthy, intact plant roots. A variety of natural with leaves, the amounts of organic materials are much smaller (Rovira, 1969). Boulterand colleagues (1986) found that greater amounts of amounts of amino acids were exuded into sand by pea roots than into solution culture. Similarly, exudation in soils can be expected to bary with soil physical and chemical properties. Root exudation usually is increased greatly by wilting conditions and root damage.

3. Volatization: - Volatization is the release of natural products into the atmosphere. A variety of plants either secretes or excretes metabolic products into special structures such as incomes and glands into intercellular spaces and canals or onto leaf surfaces. In hot dry weather, natural products with high vapor pressure released into the atmosphere where they may be associated directly by plants or adsorbed onto soil surface.

Allelopathy and Mulching:
Allelopathic interference can result from natural products released from mulches of plant residue. To improve nitrogen of crop plants plant residue mulches particularly of nitrogen-fixing species are commonly used in agroforestry systems. These plant residues may in fact result in allelopathic interference and decreases crop production.
Examples of Allelochemicals: Phenols, Benzoic acid, Aldehydes, Acetophenon, Cinnamic acid, Quinonenes, Flavonoids, tannins, Gentistic acid, etc.







Taungya and Shifting Cultivation System in Nepal:

By kamal bhusal 3:03 AM , 2 Comments

Taungya and Shifting Cultivation System in Nepal:Taungya system:

The taungya (taung = hill, ya= cultivation) is a Burmese word coined in Burma in the 1950s but it is believed that the system is much older having originated in China. The taungya method spread from Burma to other parts of word .It was introduced into South Asia as early as 1887, 1890 in Chittagong area in India and in 1895 to Bengal in this system government gave land to shifting cultivators and allowed them to grow trees and agricultural crop together. When tree canopy closed and precluded further agricultural cropping farmers were shifted to another site.

This is a modified form of shifting cultivation in which the labour is permitted to raise crops in an area but only side with the forest species planted to it. This labour is responsible for the upkeep of a plantation. The practices consists of land preparation, tree planting, growing agricultural crops for 1-3 years, until shade become too dense crop and then moving on to the repeat the cycle in a different area. In some cases crop may be grown one year before the trees are planted.

In Nepal the taungya system was started sometime in 1972 at Tamagadhi area of Bara district i.e. in the Terai Regions of Nepal. This areas was originally covered with forests consisting mainly of Shorea robusta Asna, and its associates the hills. In an efforts to sane the remaining forest and to engage the migrants in forest activities, the taungya system was practiced in that area.

Advantages of Taungya:

• Artificial regeneration of the forest is obtained cheaply.
• Problems of unemployment are solved.
• Helps towards maximum utilization of the site.
• Low cost method of forest plantation establishment.
• In every case highly remunerative to the forest departments.
• Provision of food crops from forest land ; and
• Weed, climber growth etc is eliminated.

Disadvantages of the taungya system:

• Loss of fertility and exposure of soil.
• Danger of epidemics.
• Legal problem created Susceptibility of land to accelerated erosion.


Shifting cultivation:

This from of low-input agriculture and fallow managements is common in Asia. If managed property this practice can be sustainable but depends upon the fallow period. Forest land is cleared through, burning (also known as slash and burn agriculture) for agriculture operation. Different kinds of shifting cultivation were practiced by farmers around Asian countries. This type of system is commonly practiced in Middle Mountains Region of Nepal.

Advantages of Shifting cultivation:

• Weed control.
• Easy method of clearing for agriculture.
• Suitable for root crops like banana based cropping systems.

Limitation of shifting cultivation:

• Increases soil and nutrient loss.
• Soil nitrogen is lost by burning.
• Siltation and other environmental problems.
• Low input in long run.

DEFECTS IN WOOD

By kamal bhusal on Tuesday, March 16, 2010 7:23 AM , 10 Comments

DEFECTS IN WOODVarious abnormal conditions and features of wood which permanently reduce the economic value of wood are termed as defects. However, defect caused by fungal attack and decay in wood is known as Unsoundness. The term is generally applied to the discontinuity of tissues and abnormal fibre development in wood, and unsoundness to some form or stage of decay in wood. These defects and or unsoundness in wood may either just reduce its utility or render it entirely valueless.

Defects in wood can be broadly classified into two categories which are as follows:

(A) NATURAL DEFECTS (Knots, Shakes, Cross grain, Compression)

(B) OTHER THAN NATURAL DEFECTS: These defects include the

(1) Defect caused during treatment of felled timber (Seasoning defects and Conversion defects); the seasoning defects include:- (Warping, Split, Shake, Collapse, Case hardening) and the defects due to conversion includes:-( Box heart, Machine burnt, Machine notches, Miscut, Imperfect grain)

(2) Defect resulting from activity of external agent (animals, insects and fungus)

(A) NATURAL DEFECTS:

1. Knots: Knots are common types of natural defects. As the tree increases in diameter it covers the bases of the lateral branches. The portions of the branches enclosed within the wood are called knots. If the branches are alive at the time of inclusion, their tissues are continuous with main stem of the trees are called live knots. But when a branch dies and a part of it is gradually covered by the live tissues of the wood is called dead knots.

Knots vary in its size from Pin head several centimeters in diameters.
Classification of Knots:
(i) Pin knots: less than 6.5 mm in diameter.
(ii) Small knots: 6.5mm to 20mm in diameter
(iii) Medium knots: 20mm to 40mm in diameter
(iv) Large knots: above 40mm in diameter

Knots spoil the appearance and reduce the strength properties of wood. It also raises the seasoning defects and makes difficulties during wood working.

2. Shakes: A separation of fibre along the grain of standing or freshly felled timber is called shakes. This forms crack or fissures that is generally confined to the interior part of the timber but sometimes extends to one surface.
For example: If a tree is growing in high wind areas, different stresses are set up inside it. A tension occurs on the windward side whereas compression occurs on the leeward side. If the tree is not sufficiently elastic, then separation of tissues takes place inside the trunk.

3. Cross grain: This is general term depending the deviation of the wood fibres from a direction parallel to the longitudinal axis of the tree. This can be diagonal, spiral or interlocked types in nature.

4. Reaction wood: A distinctive anatomical characteristics form typically in parts of leaning trees and its branches is called reaction wood. In branches of trees, the under parts have compression wood denser and darker than upper part.

5. Compression failures: Minor fractures are running across the grain and the fibres show crinkles structures due to compression.

6. Resin pocket: Due to excessive accumulation of resin, resin patches are found in wood is called resin pocket.

7. Constriction due to climber: This defect occurs due to climbing plants. These climbing plants do considerable damage to the tree by binding round the stem.

(B) SEASONING DEFECTS: This is caused by faulty techniques of seasoning. The different types of permanent distortion of timber and ruptures of tissues constitute separately or together, they are referred as seasoning defects.

Types of seasoning defects:

(a) Warping: The distortion in converted timber caused departure from its original plane usually during seasoning period is called warping. Warping can be culping, bowing, twist, string.

(b) Check, Split and Shakes: These are the examples of separation or ruptures of the wood along the grain. These three forms differ in whether the crack is confined to the interior of the wood or extends to the surface.

• Check: In check, there is a separation of fibres, which crack or fissures do not extend through the piece from one face to face of wood. This term is applicable for the converted timber.

• Split: Crack extends from face to face of the wood. An end split is one that occurs at the end of log or a piece of timber.

• Shakes: Separation of wood fibre along the grain and occurs in different shapes such as star, ring, etc. Shakes may be Heart and Star shake, Radial shakes and Cup and ring shake.

(c) Case hardening: During the wood seasoning, surface layer of wood usually dry before the interior layers and tend to shrink but they are prevented from doing so by the wetness of the wood. This is situation is called Case hardening. The case harder timber is liable to cuping, warping and other forms of distortion during planning and resawing.

(d) Collapse: This is abnormal and irregular shrinkage of wood. This defect is seen when very wet heartwood is dried.

(C) DEFECTS DUE TO CONVERSION: Timbers may sometimes contain defects due to faulty conversion.
Some of them are:

(a) Boxed heart: This term is applied to the timber, which is sawn in a way that the pith or the centre heart falls entirely within the surface throughout its length.
(b) Machine burnt: Defect due to overheating.
(c) Machine notches: Due to bad holding and pulling.
(d) Miscut: Careless during sawing of wood.
(e) Imperfect grain: Not matching with grain alignment.

(D) FUNGAL DEFECTS:

(a) Stain: Fungi causing stain in wood, when it feeds only on food materials stored in the sapwood. In this case, fungi do not attack the heart wood which normally does not contain food material within the cell. Stain defect does not affect strength properties of wood. For example: Ceratocystis.

(b) Decay: This is observed due to wood destroying or wood rotting fungus of wood. These fungi nourish cell wall material and break down the cell structure and enzymatic activities. Decay fungi attack both sapwood and heartwood. This defect reduces the strength properties of wood.

(E) DEFECTS DUE TO INSECTS AND OTHER ANIMALS:

(a) Insects: Insects borers and termites together constitute one of the most destructive biological agencies causing defects in timber. Some insects infest standing trees others infest felled logs before conversion or converted timber. The damage is visible in the form of tunnels and wood dust packed galleries in timber.

(b) Other animals:

• Marine borer: Mostly these insects are found in costal regions and affects wood. For example: Crustaceans, Molluscs, etc

• Birds and mammals: In birds, only wood peakers do some damage to individual trees by excavating holes in stem. Similarly, some of the animals such as deer, boar, etc cause serious wounds by peeling of the bark and damaging the cambium part of the tree.

So, defects in the wood is necessary to identify so as to prevent the timber from being damaged by insect, fungi and other animals so as to obtain the desired quality of timber.










Soil structure and water logging

By kamal bhusal on Sunday, March 14, 2010 3:53 AM , 0 Comments

Soil structure and water loggingSoil structure is the way soil particles aggregate together into what are called peds. Peds come in a variety of shapes depending on the texture, composition, and environment.

1. Spheroidal: Granular structure consists of spheroidal peds or granules that are usually separated from each other in a loosely packed arrangement. When the spheroidal peds are especially porous, the term crumb is sometimes used. They typically range from less than to greater than 10mm in diameter.

Granular and crumb structures are characteristics of many surface soils (usually A horizons), particularly those high in organic matter. Consequently, they are the principal types of soil structure affected by management. They are especially prominent in grassland types of soils that have been worked by earthworms.

2. Platy: Platy structure, characterized by relatively thin horizontal peds or plates, may be found in both surface and subsurface horizons. In most instances, the plates have developed as a result of soil-forming processes. However, unlike other structure types, platy structure may also be inherited from soil parent materials, especially those laid down by water or ice. In some cases compaction of clayey soils by heavy machinery can create platy structure.

3.Blocky: Blocky peds are irregular, roughly cube like, and range from about 5 to 5omm across. The individual blocks are not shaped independently, but are moulded by the shapes of the surrounding blocks. When the edges of the blocks are sharp and the rectangular faces distinct, the subtype is designated angular blocky. When some rounding has occurred, the aggregates are referred as sub-angular blocky. These type are usually found in B horizon, where they promote good drainage, aeration, and root penetration.

4.Prismatic: Columnar or prismatic structure are characterized by vertically oriented prisms or pillar like peds that vary in height among different soils and may have a diameter of 15omm or more. Columnar structure, which has pillars with distinct, rounded tops, is especially common in subsoil high in sodium. When the tops of the prisms are relatively angular and flat horizontally, the structure is designated as prismatic. Both prisms like structures are often associated with swelling types of clay. They commonly occur in sub-surface horizons in arid and semiarid regions and, when well developed, is a very striking feature of the profile. In humid regions prismatic structure occurs in poorly drained soils and in frangipanes.


Water logging:
Water logging is when the soil surface area becomes saturated; soil pores are full of water. Excess water can’t drain away.
Reasons:
• Heavy rain
• Poor drainage
• Poor irrigation management
• Rising water table
• Undulated land form

Control measures:
• Drain out water
• Land filling
• Water tolerant
• Wetland management
• Good irrigation facilities


Man and animal conflict

By kamal bhusal on Saturday, March 13, 2010 1:48 AM , 0 Comments

Man and animal conflict The present situation appeared on the earth sometimes during years ago while animals occupied this earth earlier. As soon as the man came on the earth , conflicts between man and animals started as he started killing animals for food and other purposes. He started his life as a hunter. After some time, he found that fruits, seeds, leaves , and other parts of plants could be utilized as food so he starts collecting those seeds and fruits from the forest and thus he starts living as hunter and gatherer and lived in wilderness system. He lived like this for considerable period of time. In due course of time, he learnt that these plants could be cultivated. It is only about ten to fifteen thousand years ago that he started cultivation of food crops and raring animals for living. After tracts and killed large number of animals. He started domestication of several species of wild animals to meet his requirement.

Human population has been increasing all over the world but more rapidly in India. During 100 years, better health care, improved food availability and better living conditions led to rapid increase in human population in India. During the year 1900, population in India was less than 17 cores. In a period of 100 years, it reached to almost 6 times to more than 100 corers. The rise in population during recent years placed a great demand on earth’s natural resources. A large stretches of forests have been converted into agriculture. Some agriculture land has been diverted to industry and habitation. Increase in population continuously led to increased demand on land, water, food, energy, consumer goods etc. Wild animals which roamed in large numbers in forests were killed for food, sport, trophy and other purposes. Tiger population which was more than 40,000 during early part of twentieth century was reduced to less than three thousand during later part of twentieth century. These pressures are still continuing causing great demand on forest, wildlife and wilderness areas.

In nature, there is balance in the ecosystem. Most organisms are dependent on other organisms. The grasses, herbs, shrubs, trees etc. which take energy from sunlight to make their own food are known as producers. There are insects and herbivore animals which eat these grasses, herbs, shrubs, etc and keep these under check. There are birds which eat insects and keep their population under control. While certain species of birds may damage crop plants, but this damages is overwhelmingly offset by the benefits. Our crop plants, orchard, our food supplies etc would be destroyed by a large number of insect species without the protection afforded by the birds. Insects have a very high multiplication capacity and if they are unchecked, they can overwhelm all life forms on this earth. In order to keep a control over the population of herbivore animals, nature has created a number of carnivore or predator animals. The carnivore animals are used for different purpose, e.g. clothing, medicine, food, trophies, etc therefore these are killed by man. Some carnivore animals are killed by other carnivores. Most ecosystems are highly complex and extremely large number of species. It would thus appear that in nature every animal has a role which helps to keep a balance in nature.
Main kinds of conflicts

Whenever man and wild animals live in the same area; conflict is inevitable. Generally the victims are the wild animals. But wild animals also cause some injury and loss to human beings; such loss and injury is generally referred to as man-animals conflict. The main conflicts are the following:

1. Loss of crops
2. Loss of livestock
3. Loss of human life and property
4. Damage to property
5. Stealing, snatching
6. Loss of grains

1. Loss of crops
Several animals cause considerable damage to crops. Most deer species especially sambar and chital; antelopes like blackbuck and blue bull; wild boar, several rodents and most birds cause considerable damage to both kharif and rabi crops in the fields located on the boundary of forests. The damage is very serious along PA’s where these animals live in considerably large numbers. While the damages by birds and rodents are more than compensated by their positive contribution in pest control, the damages by deer, antelopes, wild boar, etc is locally significant and not compensated.

2. Loss of livestock
The loss of livestock damage are mostly concentrated in districts rich in wild population. It has been found that most killings of domestic animals take place when these animals are sent for grazing in forests or PA’s rich in predators. Cattle killing cases in three districts of Gujarat which adjoin Gir, WLS namely, Amreli, Junagarh and Bhavanagar range from 1300 to 1500 cases annually. Such cases are reported in other states also particularly in areas which are rich in predator population.

3. Injury to loss of human life:
There are some cases of injury of human beings due to wild animals. There are cases of human deaths due to attack of tiger, elephant, leopard, bear, bison, etc. About ten thousand persons die annually due to snake bites in the country. The number of deaths due to the attack by tiger, leopard, elephant, bear, etc. in the country is about five hundred annually. Tiger, leopard, bear, and other predators attack the men when they encounter men of all.

4. Damage to property:
Elephants cause damage to house and other property. Such damages are common in some pockets of west Bengal, Assam, Karnataka, Kerala, and Jharkhand. Serious damages to houses and other properties have been reported from Chhattisgarh and recently from Madhya Pradesh as numbers of elephant herds enter the state of Surguja and Raigarh in Chhattisgarh and Sidhi and Shahdol districts in Madhya Pradesh.

5. Stealing and snatching:
Stealing and snatching of goods, food stuffs, etc. are done by rhesus monkeys and other monkeys. These monkeys easily mingle with human elements on the crowded platform of railway station accepting food from passengers or stealing it when they can. Common languors are venerated by Hindus and they live around tanks, temples, and establish themselves in town and cities. Due to their increased population in town and cities, they are creating several problems in towns and cities, they are creating several problems to residents.

6. Loss of food grains:
Considerable food grains are destroyed by the rodents. It is estimated that more than 1o percent food grains are destroyed every year in the country. Their rate of breeding defeats any attempts to control them. Great loss id caused by rats, squirrel, mice and other rodents to food grains, more grave is the risk of diseases caused by their presence in the midst of humans and animals.

Indigenous Knowledge (I K) in Community Forestry of Nepal:

By kamal bhusal 1:42 AM , 0 Comments

Indigenous Knowledge (I K) in Community Forestry of Nepal: Indigenous Knowledge (I K) is the knowledge gained by the HIT AND TRAIL
methods with the Passing time by serial ‘hit and trail’ methods. It refers, also to the long standing trading and practices of certain regional, indigenous or local communities. It is thus, the outcome of wisdom and knowledge of the communities that has been handed over from generation or from person to person.

IK varies from place to place as it developed initiated and produced in a particular region or with in the local community. It should also be considered that IK may not always be come as a result of the age old traditions but may sometimes also as a result of the age old traditions but may sometimes also result as the solution to the problems, people faced in their day to day livelihoods.

Ours being a traditional society, we are very rich in I K, that has been as mentioned above, handed over to us, from our fore-fathers. Some of our practice based on I K has solid scientific base while several others do not really have scientific base, rather which need to be discarded in modern. For instance, ‘untouchability’ prevailing in the society.

Forest and its associated resources (grasslands, rivers streams, etc) have always hold special value in the lives of people and that also especially for rural people. People are largely dependent on forest for their daily livelihoods get fodder, fuel wood, forage
NTFPs etc from of the forest. Owing to the over dependency of the people, in forest and its resources and increasing population, people themselves created innovative idea for still being followed as and in the from of I K.

Community Forestry though is comparatively a newer terminology, but the relation between the forest and the people living around is rather an old concept and because of this, I K has largely been in practice for forest management.

Forest User Groups (FUGs) have been practicing various silvicultural operations, harvesting practices, rotation system, etc on the basis of the IK.

Some of the aspects of Community Forestry where IK has been used are.

1. The system of appointing watchers to protect the forest is based on IK.
In the past people practiced a rotation LAURO SYSTEM for appointing such watchers. In same areas, they even collected, paddy and other items for daily living, and appointed hired a person from poor group to watch forest this system is still prevalent in same of the Community Forest User Groups(CFUGs).

2. Rural villagers are traditional and have great faith on God. They respect water resources, different plants and other natural resources as different Gods and Goddesses. People do not fell/ cut Ficus religiosa (Peepal) and Ficus bengalensis ( Bar) considering then incarnation of Lord Bishnu and scientifically also, it has been proved that Ficus religiosa gives out more oxygen than others.

3. It’s a tradition that people do not fell the tree of ‘Swami’ plant near water resources. And we know scientifically that trees help in conserving water.

4. People do not burn wood having latex for they believe tat the smoke emitted from such woods damage their eyes. For example: Khirro

5. People have developed their own way of harvesting practices. They do not have any scientific knowledge about how to fell the trees, in which direction to fell the trees using what tools. But, through their IK they harvest in such a way that the least damage is caused to the felled tree and also to adjoining trees.

6. Stone string up/Tharo Bandhne system is also one of the traditional practices which is being practiced in community forestry of Nepal.

7. Sometimes they do not fell event the old trees exceeding the harvestable age. It is maintain granary, for feeding their cattle and for mulching purposes.

8. They do not fell the trees that are habitat of large number of birds. This is indirect and unknown effort for biodiversity conservation.










RELATION OF SILVICULTURE WITH OTHER BRANCHES OF FORESTRY:

By kamal bhusal 1:35 AM , 2 Comments

RELATION OF SILVICULTURE WITH OTHER BRANCHES OF FORESTRY:1. Silviculture & Forest Protection: Forest Protection is defined as that branch of forestry which is concerned with the activities directed towards the prevention and control of damage to forests by man, animal, fire, insects, diseases and other injuries and destructive agencies. Knowledge of the injuries caused to forests by the local human and animal population, both domestic and wild, insects, fungi and other adverse climatic factors and the preventive and remedial measures to counteract them, is essential for effective protection of forests, forest protection is concerned with its protection against various sources of damage.

2. Silviculture and Forest Mensuration: Forest mensuration is defined as the branch of forestry which deals with the determination of dimensions, form, volume, age and increment of logs single trees, stands or whole woods. Thus, while silviculture deals with raising of forest crop, forest mensuration deals with the measurement of diameter and heights of crop so produced, calculation of its volume, age, etc, for sale and research to decide the best treatment to be given to the crop while it is being raised.

3. Silviculture & Forest Utilization: Forest utilization is defined as the branch of forestry concerned with harvesting, converting, disposal and use of the forest corps, Forest Utilization is concerned with harvesting and disposal of crop so produced.

4. Silviculture & Forest Economics: Forest Economics is defined as those aspects of forestry that deal with the forest as a productive asset, subject to economic laws. Thus while silviculture is concerned with the cultivation of forest crop, forest economic works out the cost of production including rental of land and or compound interest on capital spent in raising the crop and compares it with the sale proceeds to decide whether raising of the crop is economically profitable or not. It is also the function of Forest Economist to compare the cost of production of a particular crop by different methods and then decide the most profitable method of raising that crop.

5. Silviculture and Forest Management: Forest Management is the practical application of the scientific, technical and economic principles of forestry. Thus while silviculture deals with the cultivation of crop, Forest Manager manages that crop according to the Forest Act and Forest Regulation of Nepal. Silviculture deals with the techniques and operations which result in the development of a forest. Forest Management prescribes the time and place where the silvicultural techniques and operations should be carried out so that the objects of management are achieved.

The various branches of forestry are so closely related that the consideration of one branch influence the techniques of other branches.

For example: Silvicultural techniques and operations are governed by the considerations of cost and modified to suit the requirement of protection. Similarly, even the most profitable method of exploitation.

So, Forestry has a wide scope and silviculture is only one of its branches. It has the same relation with forestry as agronomy has with agriculture. While agronomy and silviculture deals with cultivation of crops, agriculture and forestry deal not only with the cultivation of crops but also with their protection, management, mensuration, marketing, etc. In short, forestry is an applied science which has many branches. It may be compared to a wheel. Silviculture is the hub of the wheel. It is neither the whole wheel not is it the essential part. But just as a cart wheel composed of several sections is supported on its hub, similarly forestry and its other branches are supported on silviculture without which there would be neither forestry nor its branches.

Soil Microorganisms:

By kamal bhusal on Friday, March 12, 2010 3:28 AM , 2 Comments

Soil Microorganisms:Microorganisms constitute< 0.5 %( w/w) of the soil mass yet they have a major impact on soil properties and processes.60-80% of the soil metabolism is due to the micro flora. In numbers, soil microorganisms beat out all other organisms. One gram of topsoil my contain

  • as many as one billion bacteria
  • Up to 100 million actinomycetes
  • One million fungi
  • 100 nematodes.
Importance of Soil Organisms:

  • Responsible for cycling of C, N and other nutrients.
  • Enhances soil structure.
  • Relocate and decompose organic materials.
  • Maintain soil quality and health.
  • Increase soil aeration and penetrability.
  • Involved in disease transmission and control.

Plant Roots: the Rhizosphere:

The narrow region of soil directly around roots, teeming with bacteria that feed on sloughed-off plant cell and proteins and sugars released by roots. Protozoa and Nematodes graze on bacteria; also concentrated near roots.

Soil Fauna (or zoo):

  • Macro fauna :Mice, moles, etc, Earthworms and other worms, Ants, beetles Termites , spiders.
  • Mesofauna : Nemaodes, arthropods (mites, centipedes, and springtails ), molluscs
  • Microfauna: Protozoa
Soil macro fauna: Earthworm

1. Important in mixing and redistributing OM.
2. Enhances soil physical properties.
. Neutralize soil pH.
4. Increase the availability of many nutrients.
5. Stimulate microbial population.
6. May reduce levels of harmful nematodes.

Soil Mesofauna: Nematodes

1. Microscopic non-segmented roundworms.
2. Ecologically diverse.
3. Found in all habitats.
. Overall, 10-20 million/m-sq is found.
5. Major consumer group.
6. Both free-living and parasitic groups exists

Soil Microfauna: Protozoa

1 Important in mineralization and immobilization of N,P, and S
2. Most numerous soil fauna
3. Prey on microbes (especially bacteria)
4. Enhance nitrification rates
5. Suppress bacterial and fungal pathogens
6. Can be agents of plants disease

How can we see the organisms in the soil?

Pitfall tarp to catch large arthropods by sinking a pint-or quart-sized container is made. (Such as a yogurt cup) into the ground so the rim is level with the soil surface. If desired, fashion a roof over the cup to keep the rain out, add 1/2 of an inch of non-hazardous antifreeze to the cup to preserve the creatures and prevent them from eating one another Leave on place for week and wait for soil organisms to fall into the trop. To make a Burlese funnel to catch small arthropods, set a piece of ¼ inch rigid wire screen in the bottom of a funnel to support the soil. Half fill the funnel with soil, and suspend it over a cup with a bit of anti-freeze or ethyl alcohol in the bottom as preservatives.

Desertification

By kamal bhusal on Wednesday, March 10, 2010 5:15 AM , 1 Comment

DesertificationDesertification is the process which turns productive into non-productive desert as a result of poor land management. Desertification occurs mainly in semi-arid areas (average annual rainfall less than 600mm) bordering of deserts.

Causes of Desertification

• Overgrazing is the major cause of desertification worldwide. Plants of semi-arid areas are adapted to being eaten by sparsely scattered, large, grazing mammals which move in response to the patchy rainfall common to these regions. Early human pastoralists living in semi-arid areas copied this natural system. They moved their small groups of domestic animals in response to food and water availability. Such regular stock movement prevented overgrazing of the fragile plant cover.

• Cultivation of marginal lands, i.e. lands on which there is a high risk of crop failure and a very low economic return, for example, some parts of South Africa where maize is grown.

• Destruction of vegetation in arid regions, often for fuel wood.
• Poor grazing management after accidental burning of semi-arid vegetation.

• Incorrect irrigation practices in arid areas can cause salinization, (the build up of salts in the soil) which can prevent plant growth.

Increasing human population and poverty contribute to desertification as poor people may be forced to overuse their environment in the short term, without the ability to plan for the long term effects of their actions. Where livestock has a social importance beyond food, people might be reluctant to reduce their stock numbers.

Effects of Desertification:

Desertification reduces the ability of land to support life, affecting wild species, domestic animals, agricultural crops and people. The reduction in plant cover that accompanies desertification leads to accelerated soil erosion by wind and water. South Africa losing approximately 300-400 million tones of topsoil every year. As vegetation cover and layer are reduced, rain drop impact and run-off increases.

Water is lost off the land instead of soaking into the soil to provide moisture for plants. Even long-lived plants that would normally survive drought die. A reduction in plant cover also results in a reduction in the quantity of humus and plant nutrients in the soil, and plant production drops further. As protective plant cover disappears, floods become more frequent and more severe. Desertification is self-reinforcing, i.e. once the process has started, and conditions are set for continual deterioration.

How can desertification be halted?

To halt the desertification the number of animals on the land must be reduced, allowing plants to re-grow. Soil conditions must be made favorable for plant growth by, for example, mulching. Mulch( a layer of straw, leaves or sawdust covering the soil) reduces evaporation, suppress weed growth, enriches soil as it rots, and prevents runoff and hence erosion. Reseeding may be necessary in badly degraded areas. Mulching and reseeding are expensive practices.
However, the only realistic large-scale approach is to prevent desertification through good land management in semi-arid areas.

As a forester, what can we do?

Desertification often occurs over many generations on a very large scale and so it is difficult for individuals to take actions. Some ideas for combating this problem include:
• Participation in the activities of conservation groups is needed.
• Problems of overgrazing and land mismanagement are to be taken care into attention.


Forest Nursery

By kamal bhusal 5:03 AM , 9 Comments

Forest NurseryAs we all know that nursery is an area where plants are raised for eventual planting out. It consists of paths, nursery beds, irrigation channels etc. On the basis of the kind of plants growing in them, nursery beds are classified into seedlings bed and transplant beds. Seedling beds are those nursery beds in which seedlings are raised either for transplanting in other bed or for planting out.

A nursery which has only seedling beds i.e. in which seedlings only are raised, no transplanting being done is called seedlings nursery. Transplant beds are those nursery beds in which seedlings in which seedlings raised in seedling beds are transplanted before planting out in forest. A nursery which has only transplant beds i.e., in which seedlings are transplanted in preparation for forest planting is called transplant nursery.

• For artificial regeneration plants have first to be raised under protected condition and then transplanted out in the field to grow into a forest.

• Plants are produced for fodder, forest, fruit and bioengineering requirements.

Importance of Forest Nursery:

1. Some important species do not need seed every year. Plantation of these species can be raised annually only by collecting all available seed in years and sowing it in nursery to raise seedlings to be planted out in various years.

2. Some species grow very slowly and if the seed of these species is sown directly in plantation, the seedlings are most likely to be swamped by weeds and killed. Therefore, slow growing species are generally raised in nursery and planted only when the seedlings are not liable to be damaged by weeds.

3. Success of roadside avenue plantations depends largely on planting tall and study plants which can only be obtained from nursery.

4. Plantations of some species when raised by direct sowing are not so successful as when raised by planting. In such cases, nursery is an essential part of artificial regeneration of those species.

5. The best method of introduction of exotics, viz tropical pines, poplars, Eucalyptus, etc is only by planting and therefore nursery is very essential for them.

6. Planting of nursery-grown plants is surest method of artificially regenerating poor and barren sites.

7. Causalities in plantations have to be replaced either in the year of formation or in the next year. Sowing done in the gaps are liable to be unsuccessful as a result of suppression from weeds and cannot catch up the plants from original sowing. Therefore, replacement of causalities is always is done by planting nursery-grown plants or stumps and so nursery is very essential for causality replacement.

Nursery Site Selection:
The selection of an appropriate nursery site is the most important decision affecting the efficient production of good quality plants. The following are some of the technical factors which need to be considered while setting a nursery.

1. Water Supply: In order to have the good irrigation facilities, it should be situated near or slightly below the source of adequate water supply. Reliable (understanding with villagers) and adequate water supply is essential. Water source should be near and at the higher level than nursery site. Water should be available throughout the year.

2. Availability of suitable soil: For raising seedlings in polythene pot (tube) soil of the actual nursery itself is not important. There should be suitable source of soil preferably forest topsoil and sand within easy reach of the nursery. Clayey soils should not be selected as their aeration and drainage is poor and they are liable to crack during summer.
The symbiotic organism (Micorrhiza and Rhizobium) should be present in soil for following reasons.
• Most of the trees grow best if their roots are associated with certain symbionts, which help in their nutrition.
• Mostly these organisms are found naturally but in some cases artificial inoculation are needed.

3. Access: nursery should be situated as centrally as possible with reference to the area to be planted. It should preferably be near a Ranger’s or forester’s quarter for close and regular supervision i.e. nursery should be near to the plantation site to supply soil and other materials and other transportation of seedlings and access road should be usable at all seasons of year.

4. Aspect: Slope with Southey aspect is much warmer and chosen for hill nursery at high elevation while in low elevation north facing slope is chosen.

5. Slope: The ideal slope is about 5 degree which is steep enough to allow proper drainage.
Complete flat land should be avoided; it is likely to become water logged during monsoon rains.
Steeper slopes will have to be terraced and very steep slopes should be avoided as it, may be difficult to make a nursery bed and path on each side to allow access to the beds.

6. Exposure to frost, strong winds and flooding: at high altitudes, sites, which are particularly liable to frost damage, should be avoided. Sites exposed to strong winds and with danger of flooding or landslides should be avoided.

7. Labor availability: labor should be available without difficulty preferably near a village so that they don’t have to walk much for work.

8. Availability of land: There should be enough land to raise the numbers of seedlings needed and if possible room for expansion. Legal enquiries should be made about the legal ownership of the land.

Climate Change: A Burning Issue

By kamal bhusal on Sunday, March 7, 2010 9:50 PM , 0 Comments

Climate Change: A Burning Issue<br /> Climate Change: A Burning Issue
Introduction:

Climate Change can be defined as the fluctuation in regular pattern of rainfall season, air pressure and core temperature of the earth. Nowadays, environmental problems are being increasingly rapidly due to climate change and so it needs to be discussed. With the rapid growth in industrialization and production of green house gases (Carbon dioxide, Methane, Nitrous Oxide etc) natural pattern of climate change has largely been affected. This means that anthropogenic activities have increased the emission of green house gases (GHGs) in the atmosphere. The GHGs in the atmosphere trap the heat and raise air temperatures near the ground, acting like a green house on the surface of the planet. Rise in temperature has greatly impacted the planet. Earth- the life supports system. Besides these, climate change has resulted in the irregular growth and extinction of plant species and the wild animals especially the Snow Leopard living in the snowy area or in high mountain region are in a condition of threat. Birds have started laying eggs earlier than usual due to climate change.
Climate Change in Nepal:

Nepal participated in the climate change business right from the Convention preparation process in 1991. Nepal signed the Convention on 12 June, 1992 during the UN Conference on ENVIRONMENT AND DEVELOPMENT at Rio de Janeiro, Brazil. The instrument of ratification was submitted to the Convention Depository on 2 May, 1994 and the UNFCCC has entered into force in Nepal on 31 July 1994 as per the Convention provision. Similarly, Nepal submitted the instrument of accession to the Kyoto Protocol to its depository on 16 September, 2005. In order to expedite CDM projects, and get benefits from them, the Government of Nepal (GoN) has made the Ministry of Environment (MoE) responsible to function as the Designated National Authority(DNA) on 22 December 2005.

Nepal is very much susceptible to climate change. Although Nepal shares less than 0.025 percent of the global GHGs emission, it is already witnessing the visible effects of climate such as accelerated snow and glacier melting thereby increasing in the size of glacier lakes that might increase GLOF(Glacier Lake Outburst Floods). The ‘Tso Rolpa’ is an excellent example of increasing size in the Nepal Himalaya. Climate change induced impacts are also noticed in rainfall variation, and forests and biodiversity. Landslides, floods and unexpected droughts are increasing which might have a direct bearing on human health and food security. The number of cold days and cold nights are decreasing or number of hot days and hot nights are increasing. Impacts of climate change in the Himalayas would have multi-fold and unimaginable effects in the downstream thereby requiring additional efforts to lessen the impacts of climate change of both at the origin and the downstream. Nepal Himalayas are the major sources of fresh water not only for Nepal but also for South Asia. Global warming affected Himalayas resulting in retreat of glaciers of which over 20 are very vulnerable.
Predictions indicate that Nepal’s rivers will enjoy increased water flow by 2030 and suffer from reduced flow by the end of 21st century. It is considered that snow melting will increase water flow up to a certain period after which it might gradually decrease which might be attributed, ‘inter alia’, to snow formation process. In this context it is natural to think that international community should have additional understanding on natural linkages, interrelationship and interdependencies between the mountains and the lowlands.
Opportunities:

As the impacts of the climate changes are inevitable, adaptation would be the area of prime concerns for Nepal. Being the most vulnerable mountainous countries and greatly affected by the impacts of climate change, collaborative efforts are expected to provide ample opportunities for sustainable economic development and sustained management of natural resources in Nepal. The climate change regime, if implemented in “good faith” in accordance with the provision, inter alia would contribute a lot in building capacity, ensuring financial flows and technology transfer, and implementing a number of adaptation activities and promoting carbon sinks, and also promoting clean energy development path or expand low emission economy in the country. Nepal is affected and will continue to be affected by the poison although it has not taken it. Hence, Nepal leads to take them as opportunities and should make every effort to benefits from climate change regime. This might be one of the areas for financial flows for socio-economic development of the country.

Solar radiation and its effects on vegetation

By kamal bhusal on Saturday, March 6, 2010 5:15 AM , 1 Comment

Solar radiation and its effects on vegetation<br /><br />

Solar radiation and its effects on vegetation


The energy which is responsible for the growth of vegetation and all life depending on it, in this earth comes directly or indirectly from the sun. Thus the nature and amount of solar radiation received on the surface of the earth is a factor of great importance. The energy radiated by sun reaches the earth in the form of electromagnetic waves of varying length, ranging nearly from 290 millimicrons to 5300 millimicrons.
The maximum energy of solar radiation occurs in the green and yellow regions of the visible spectrum (400mµ to 720mµ). Since the heat produced by the radiation is independent, in its effect, of the wavelength, the intensity of radiation is generally measured by the heart generated by it. The solar radiation reaching the earth is further is affected by latitude, altitude, season of the year and time of the day. As latitude increases, the intensity of solar radiation decreases. With increase in altitude, the radiation increases. The most important effect of solar radiation is that it provides both light and heat (temperature).
Importance of Light


1. Chlorophyll formation: Light is one of the important and essential factors responsible for chlorophyll in plants. Without light plants become pale yellow and have long thin internodes, a condition known as 'etiolating.' Chlorophyll decomposes in bright sun light; thus formation and decomposition both go on simultaneously when the plant is exposed to light.
2. Functioning of stomata: Light is an important factor influencing the daily opening and closing of stomata, which in turn, affect respiration and photosynthesis.
3. Photosynthesis: Light is the most important factor of locality for photosynthesis as it can not take place in darkness. Out of the seven colors in visible part of the spectrum, only red and blue are effective in photosynthesis. It has been estimated that light used in photosynthesis is less than 2 percent of the light energy incident on well-illuminated leaves.
4. Growth: Light influence the growth of plants and trees through its effect on photosynthesis. The influence of light varies with its quality, duration and intensity. Quality of light refers to colors. Plant growth in blue light is small. Red light on other hand results in elongation of cells giving the appearance of etiolated plants. Violet and ultraviolet light bring about dwarfing effect.
5. Form and quality of trees: The elongation of the growing axes of tree in the forest occurs mainly between sunset and sunrise because the low intensities of light and infrared radiation tend to stimulate height growth. Even the form of trees growing in shade is very dissimilar to that of trees growing in the open.
6. Species stratification and size and structure of leaves: The intensity of light in the forest varies from place to place and from time to time between wide limits.
Light requirement:


1. Light demander is a species that requires abundant light for its best development.


2. Shade bearer is a species capable of persisting and developing under shade.


3. Shade demander is species requiring, at least in its early stages, some degree of shade for its normal development.

Soil Organic Matter

By kamal bhusal on Thursday, March 4, 2010 6:30 PM , 1 Comment

Soil Organic Matter<br /><br />

Soil Organic Matter

Soil Organic MatterOrganic matter is defined as the organic fraction of the soil. Organic matter in soil consists of the remains of plants and animals. When temperature and moisture conditions are favorable in the soil, earthworms, insects, bacteria, fungi, and other types of plants and animals use the organic matter as food, breaking it down into humus( the portion of organic matter that remains after most decomposition has taken place) and soluble nutrients. Through this process , materials are made available for use by growing plants. In addition, organic material has a very high cation exchange capacity, so nutrients are retained in plant available form. The digested and decomposing organic material also helps to develop good soil-air -water relationships. Organic matter is capable of absorbing large quantities of water and thus increases the water holding capacity of the soil.
In sandy soil organic matter occupies the space between the sand grains, thus binding these together and increasing water-holding capacities. In a finely textured or clay soil, organic material on and around soil particles creates aggregates of the fine soil particles, allowing water to move more rapidly around these larger particles. This grouping of the soil particles into aggregates makes soil mellow and easier to work.
Beneficial impacts of Soil Organic Matter on soil properties:


1. Physical : Stabilizes soil structure, improves water holding characteristics, lowers bulk density, dark color may alter thermal properties.


2.Chemical: Higher cation exchange capacity, acts as a PH buffer, ties up metals, interacts with xenobiotics.


3. Biological: Supplies energy and body-building constituents for soil organisms, increases microbial populations and their activities, source and sink for nutrients, ecosystem resilience, affects soil enzymes.
Each year , about 1 percent to 4 percent of nutrients in the soil organic matter are released through microbial transformation to become available to plants. Release is highest under warm, moist conditions and slowest in cool dry climates. Microorganisms are the driving force for nutrient release to plants.


By kamal bhusal

An introduction to Forest Soil

By kamal bhusal 12:11 AM , 2 Comments

An introduction to Forest Soil
An introduction to Forest Soil

Forest soil is characterized by the content of high organic matter (OM) due to accumulation and decomposition of leaf litter and other plant parts. It contains higher number of microorganisms than the cultivated soil. There is no disturbance in soil profile i.e. well defined soil profile can be seen. Forest soil contains high moisture level due to low evaporation. Acidic soil is found in are where Pinus roxburghii grow. Forest soil is dark black in color.

Effect of vegetation on soil:
Effect of vegetation on soil can be viewed into two groups i.e. advantageous effects and harmful effects.
Advantageous effect
1. Addition of organic matter.Justify Full
2. Protect soil from erosion.
3. Conserve soil moisture (prevents from evaporation)
4. If there are leguminous plants, it helps to fix nitrogen into the soil.
5. Works as mulching materials which help to control weed.
6. Recycling of nutrients.
7. Make microorganism more efficient.
8. Improves infiltration capacity of the soil.
9. Vegetation helps to reduce soil compaction due to root penetration in the soil and addition of organic matter.
10. Make soil more porous due to the presence of organic matter.

Harmful effects
1. Soils under pine trees have been found acidic.
2. Reduce soil moisture due to increased transpiration.
3. Deficiency in soil nutrient due to regular use by vegetation.
4. Habitats for insects, pests and diseases.
5. Reduction in microbial activity due to the shading effect of vegetation.
6.Vegetation dominated by pine trees increased surface runoff in sloppy site due to the compaction of soil or due to dryness in soil.

Wildlife Conservation

By kamal bhusal on Wednesday, March 3, 2010 1:05 AM , 0 Comments

Wildlife Conservation

Wildlife Conservation
Background: Conservation means protection as well as sustainable utilization of biome or other resources. They are meant for human beings and their volume should not be decreased. In conservation there should be balance between protection and utilization.

In other words, it can be defined as the planned management of natural resources to prevent exploitation, destruction or neglect. If some protective measures are not taken, it will lead to extinction or perish.
Nepal has always been very famous for big game hunting and in the past it was known as sportsman's paradise. However, hunting as it locally called, has never been organized on a commercial basis. Thrilling scenes of big game hunting made by using primitive means and methods are depicted in the contemporary paintings of the 19th century. Several methods of hunting were used in the past which are quite interesting to discover in the present context.

Recently, for conservation of the wildlife resources, to protect the unique ecosystem to provide recreational opportunities and scientific studies some National Parks and Wildlife reserves have been established. These Parks and Reserves are located in the Terai, mid-land and Himalayan region and they are very fascinating as they support the variety of flora and fauna as well as human inhabitation. Nature indeed has bestowed upon Nepal the glories and grandeurs of enchanting scenery presented by green forests, a panorama of high mountains, overflowing rivers and crystal clear lakes. Nepal still can boast of her rich and varied fauna and flora.
Now stress has been laid to a great extent on the conservation and management of wildlife together with other flora and fauna on a scientific basis both ecologically and economically.

Methods of wildlife Conservation
1. Establishment of protected areas: The establishment of national park and reserves, sanctuaries etc serves many purposed to conserve species wild state, to provide scientific, educational and recreational opportunities and to earn revenue by attracting tourists.

2. Habitat Management: It includes ecological study of habits and habitats of wildlife species, protection, preservation and improvement of habitats. It also includes census and statistical data about species to be conserved.

3. Breeding in captivity: Several species survived only in captivity. Animals like gorilla, tiger, etc survived only in park and reserves. Species are saved from extinction in captive breeding.

4. Mass education: For achieving the conservation programme there is a need of educating the people. Following are the important methods adopted publicity through media and film shows, holding conducted tours, essay competition, lectures, seminars etc., establishment of nature clubs in educational institutions, publication of wildlife books, magazines, journals, establishment of National Museum, celebration of wildlife week every year ,etc.

5.Protection by laws: All countries have promulgated laws for protection and conservation of wildlife. In Nepal, National Park and Wildlife Conservation Act was promulgated in 1973. In 1957 laws were introduced which provided protection of Great one-horned rhinoceros and its habitat. In 1964, a rhinoceros sanctuary was established which is now a part of Chitwan National Park(oldest park of Nepal). In Nepal, all wildlife protected areas are guarded by military. However more heavier and deterrent punishment for poachers is required by amendment of existing laws.

Fuel wood as a source of energy in Nepal

By kamal bhusal 1:01 AM , 1 Comment

Fuel wood as a source of energy in Nepal

Fuel wood as a source of energy in Nepal
In Nepal fuel wood is the main source of energy for heating and cooking purposes and forest remain the single most important source for firewood, particularly for rural people. Forest account for 78 percent of energy consumption.
The pattern of energy consumption is changing along with the economic growth and urbanization. The use of traditional sources of energy such as cow dung and agricultural residues declined from 22 percent to 9 percent while the consumption of energy from the commercial sources such as coal, petroleum products and electricity increased from 4 percent to 12 percent. However, the major percentage share is still fuel wood. ThJustify Fulle rural people still depends on firewood to meet their energy demand for cooking and heating purposes due to lack of alternative sources of energy at affordable prices. Firewood is still considered as the 'free gift' of nature and people are reluctant to pay for it. As many rural people Justify Fulldepend on firewood, its consumption has increased along with population growth. Fuel wood and fodder collection has adversely affected the growing stock of the natural forests and maturity of plantation forests.

Why rural people use fuel wood?
People living in the rural areas/ villagers mostly due to the following reasons.

o Wood is easily available
o No transportation is required
o Useful for both heating and cooking purposes.
o Obtain from waste woods
o High calorific value such as Shorea robusta(22.74MJ/kg), Alnus nepalensis(18.23 MJ/kg)

Methods for efficient use of fuel wood: To reduce consumption of the fuel wood quantity, there are some alternative methods that have been applied in the rural areas of Nepal.
1.Improved stove: It is a special structure made to reduce fuel wood consumption with mud and stone. This stove is good for health and environment as it controls the rate of smoke flow.

2.Charcoal: Charcoal is a from of wood consists in burning without contact with the air. If wood is burnt in the presence of air, it is converted into small quantity of ash. If air is largely excluded during the process of burning, combustion is retarded and wood is partially burnt and the residue left behind it is known is charcoal. In city areas of Nepal, blacksmith and metal workers mostly use charcoal for melting ores.

3.Bio-briquettee: It is also known as' Beehive-briquette'. It is an alternative source of energy made from herbs, shrubs and other waste materials derived from forest. It can be easily used in houses and offices. It is an effective source of energy which does not affect the health as it is smokeless. It can be alternatively used in place of fuel wood, kerosene, gas and electricity etc.


Conclusion: To sum up, it can be said that majority of the people living in rural areas are heavily dependent on forest in order to fulfill the demand of fuel wood. Since the rural people don't have any technical knowledge regarding management of forest , so it is necessary to provide education to make them aware so that forest can be sustain ably managed.

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