Forest Fire Causing Poor Stocking of Santalum Albumand Terminalia Chebula in Southern India
(IFFN No. 22 -April 2000, p. 28-30)
Forest fires whether natural or unnatural have a significant role in the Eco-system dynamics. The unnatural fire in Indian Sub-Continent is at the maximum due to various causes. Amongst them the main culprits are graziers, encroachers, M.F.P collectors etc. who put fire in the forest just to fetch their basic needs and they are totally unaware of the biodiversity and its importance. In the process of repeated fires not only it is withdrawing soil support system but also leads to innumerable loss of various flora, fauna, insects, arthropods etc. each of which plays a vital role in the growth of forest. Any disturbance to one of them leads to imbalance the ecosystem. Recurrent fire decreases the green cover through prevention of regeneration and leads to the slow death of the forest (Ranganathan 1934). It also increases erosion and alters the physical and chemical properties of the soil converting organic ground cover to soluble ash and modifying the microclimate through the removal of overhead foliage. The soluble ash is washed away in the next rain. Fires can also make trees more susceptible to insect attack. For the sustainable development of the forests repeated forest fires has to be checked. Otherwise the loss of biodiversity will be on the increase every year at the cruel hands of few human beings and many of the species will disappear even before they are documneted.
The biological resources – genes, species and ecosystem which have actual and potential values to the people – are the physical manifestation of the globes biological diversity i.e. Biodiversity which is simply stated as the variety and variability among the living organisms and the ecological complexes in which they occur. Species are the building, blocks of ecosystems, which provide the life support systems for humans. Biodiversity is an umbrella term covering the totality of species, genes and ecosystems but biological resources can actually be managed. (Srivastava 1998) They can be consumed or replenished and they can be the subjects of directed conservation action. The loss of the world’s biodiversity, mainly from habitat destruction, forest fires, over harvesting, pollution and inappropriate introduction of foreign plants and animals is continuing. Natural plant cover being the important natural resources of the earth has been steadily depleted in the recent past. It is estimated that upto half the world’s woodlands and forested areas might have vanished since 1950 and yearly losses are not between 1-22 percent i.e. 20-50 million acres on global basis. Therefore the importance of conserving the valuable natural resources is very much felt.
The ancient civilization leads to the modern civilization and the latter leads to industrialization. In the process of which the human beings have evolved, no doubt, modern techniques at the cost of destruction of own habitats. Indiscriminate cutting, and forest fire have attributed to poor stocking to the composition of various flora and fauna. In this paper two very important species which have been severely affected in southern India by way of human interference and recurrent fire is highlighted. One is Santalum album, the costliest scented wood in the world while the other one is Terminalia chebula, a highly medicinal valued species.
Sandalwood is the fragrant heartwood species of genus Santalum (family Santalacceae). In India, the genus is represented by Santalum albumLinn. Its wood, known commercially as “East Indian Sandal wood” and essential oil from it as “East Indian Sandalwood oil” are among the oldest known perfumery materials. The word Sandal has been derived from Chandana (Sanskrit) and Chandan (Persian). Itis called Safed Chandan in Hindi, Srigandha, Gandha in Kannada. Sandanam in Tamil, Chandanamu in Telegu. Histo rical review reveals that sandalwood has been referred to in Indian mythology ,folklore and ancient scriptures. It is generally accepted that sandal is indigenous to peninsular India as its history of recorded occurrence dates back to at least 2500 years. The sandal family is distributed between 30° North and 40° South from Indonesia in the West to Juan Fernandez Island in the North, to New Zealand in the South. (ICFRE).
In India Santalum album is found all over the country, with over 90% of the area in Karnataka and Tamil Nadu covering 8300 Sq.Kms. In Karnataka it naturally in the southern as well as Western parts over an area of 5000 Sq.kms. In Tamil Vadu, it is distributed over an area of 3000 Sq.kms. and dense population exists in North Arcot (Javadis and Yelagiri hills) and Chitteri hills. The other states where sandal trees are found are Andhra Pradesh, Kerala, Maharashtra, Madhya Pradesh, Orissa, Rajasthan, Uttar Pradesh, Bihar and Manipur.
The tree flourishes well from sea level upto 1800m altitude in different types of soil like sandy, clayey red soils, lateritic loamy and even in black cotton soils. Trees growing on. stony or gravelly soils are known to have more highly scented wood. Generally this species is located in the undulating terrains and survives well in the moderate rainfall of 600 to 1600mm and temperature varying between 20°C and 45°C. It grows well in early stages under partial shade but at the middle and later stages shows intolerance to heavy overhead shade.
Approximately a century back the habitat was not under severe pressure and was thriving well. Slowly and slowly with increase in population, greed indiscriminate felling and recurrent fires have depleted the stocking, Generally Santalum album fruits in two seasons in April-May and subsequently in October-November. But these new recruits which come up well in the South west monsoon and North east monsoon get affected with severe blows of forest fire in the month of January – April leaving behind poor stocking of species leading to mosaic pattern of its distribution.
Even some time the fire is so severe that it affects the cortex of the tree thereby the tree develops crack and is easily attacked by insects and in the process of which the tree dies. It. has been noticed that the areas more prone to the fire are subject to the attack of spike diseases in the tree. McCarthy has first noticed it as early as 1899 in Frazerpet (Coorg, Karnataka). The disease is caused by mycoplasma like organism. It occurs at any stage of development of the tree. As the disease progresses, the new leaves become smaller, narrower or more pointed and fewer in number with each successive year until the new shoots give an appearance of fine spike. At the advanced stage of disease, the inter-nodal distance on twigs becomes small, haustorial connection between the host and sandal breaks and the plant dies in about 2 to 3 years. Apart from this, due to recurrent fire, invasion of exotic weed Lantana camara in this type of forests does not allow the species to grow in its composition in any way and influence of spike disease in Santalum album in other way. in one way forest fire affects the matured trees by giving continuous heat effect to the trunk which subsequently leads to suppression of growth and in other way the natural regeneration which already existed in the previous years gets washed away with the flame of forest fire. This vicious process of destruction of this particular species has lead to the poor stocking in Southern India on the one hand by way of forest fire and on the other by indiscriminate cutting by sandalwood smuggling.
Terminalia chebula, moderate sized, large deciduous tree with round crown, spreading branches and usually short trunk throughout in Burma it often grows tall and straight with dark brown colour bark often longitudinally cracked, exfoliating in woody scales. It is widely distributed in the greater part of India and Burma in mixed deciduous forests of comparatively dry types. It extends to considerable elevation upto 5000′ in outer Himalayas. In Burma it occurs in dry deciduous forests both in upper and lower mixed types along with Teak, Terminalia tomentosa and their associates. It feels comfortable to laterite, clayey as well as sandy soils. In the peninsular India it is found in mixed deciduous forests to dry deciduous forests and extends upto high elevation of 3000′. In Tamil Nadu it is one of the pride tree in the Eastern Ghats. Specifically Kalrayan hills is rich in best base population of Terminalia chebula. (Anon 1996). It survives well with the temperature between minimum 30° – 60° F. and 100° – 180° F and rainfall from 30″ to 130″. It is fairly hardy against frost as well as drought. It withstands fire well and has good powers of recovery from burning. It Coppices fairly well. The fruit is drupe, and ellipsoid to obviate in shape with yellowish orange brown.
Terminalia chebula is widely distributed from Himalayas to Southern India. The best stocking, is confined to lower Himalayas as well as Southern India particularly in Kalrayans and Pachayamalai hills of Eastern Ghats. But these hills, which in the past had very good stocking were badly affected due to fragmentation of these hillocks due to human pressure by way of illicit lopping and chopping and annual burning of the area in the process of collecting fruits, which subsequently has given a severe blow on the soil texture. The type of forest where it has found place gets frequently burnt and in the process of which seeds and new recruits get wiped away with the sweep of flame in the forest fire and in the next rain, it takes away the top fertile soil. This vicious process attributes to sterility and poor stocking of species annually. The humus formation process is stopped. Microorganism’s population gets reduced subsequently leaving behind sterile soil, which is insufficient for the germination of seed of Terminalia chebula. As Terminalia chebula is a drupe and hard-coated seed it requires longer period for its decay, which is only possible with. the help of moisture and sufficient humus. The soil certainly lacks these contents in this area the result of which is at present the different age plants are not available in this forests. Only old trees are standing in the hills. Once felled down, these trees will be facing extinction the next century. Since this particular species is found only in the slopes, in summer due to heavy wind they fall down. Unless it is checked, the stocking of this particular species cannot be improved.
The two important species Santalum album and Terminalia chebula, which is having highly commercial value and medicinal value respectively is facing severe problem due to forest fire leaving behind poor stocking. In the form. of fire, new recruits get. eloped away. Unless sincere efforts is not being made this species will be at the verge of extinction which can be done by way of creating awareness so that intentional fire can be avoided to facilitate germination of these species for better stocking. It also requires creation of germplasm bank of’ these by identification of best phenotypes and genotypes and multiplication for planting stock improvement.
Rajiv K. Srivastava Deputy Conservator of Forests Dhamapuri Division Dharmapuri-636 705 Tamilnadu INDIA
Anon, 1996; Wealth of India Raw material C.S.I.R., New Delhi No. 10 pp 177-179
Indian Council of Forestry Research and Education; Dehra Dun; Brochure Sandal; 1997
Ranganathan C.R ; 1934; Working plan for the North Coimbatore forest division, Chennai
Srivastava. K. Rajiv, K. Chidambaram and G. Kumaravelu 1998; Impact of forest fire and biotic interference on the biodiversity of Eastern ghats; Indian Forester, May, 1999.