Disappearing Dalbergia sissoo from the Indo-Gangetic Plain of India
-Dr. Arvind Singh
What is the Indo-Gangetic Plain?
The orogeny of Himalayas in a tertiary period of the Cenozoic era had led to the formation of a large depression which was filled by the fine sediments brought by the Himalayan Rivers resulting in the formation of alluvial plain in the quaternary period of Cenozoic era, known as Indo-Gangetic Plain. The Indo-Gangetic Plain of India is most recent in origin constituting about 15 percent of the land area of the country lying between Extra-Peninsular (Himalayas) and Peninsular India (Precambrian in origin).
Characteristics:
Distribution and Ecology:
The Dalbergia sissoo is native to India, Pakistan, and Nepal. It is found throughout the sub-Himalayan tract up to 1,500 m altitude and in Indo-Gangetic Plain. It is found growing gregariously on freshly exposed soil along roads, streams, and landslips. The Dalbergia sissoo is a typical tree of alluvial soils along river banks and islands. It prefers well-drained, alluvial sandy or gravelly soil with adequate moisture supply. The tree species avoids the ill-drained clayey soils and swamp. It is drought hardy and frost resistant and is also a strong light demander. It has the ability to tolerate a temperature range of 4-49ºC.
The Indo-Gangetic Plain of India has traditionally been the most favorable habitat for the growth and yield of Dalbergia sissoo. In fact, this Physiographic zone represents the best belt of Dalbergia sissoo in the world. Earlier the Dalbergia sissoo was extensively cultivated in the state of Uttar Pradesh, Bihar, Jharkhand, Punjab, Haryana and West Bengal for its multiple uses.
The Dalbergia sissoo was the most favorite tree species of the Forest Department in past for the afforestation along roadsides, canal banks and railway tracks in the Indo-Gangetic Plain of India.
Economic Importance:
Dalbergia sissoo is a tree species of immense economic importance. The heartwood is brown with darker streaks, very hard, strong and durable. The heartwood of Dalbergia sissoo is classified as one of the four primary timbers of India, the others being Tectona grandis (Sagwan), Shorea robusta (Sal) and Cedrus deodara (Deodar). On account of its great strength, elasticity and durability it is highly valued as constructional and general utility timber. The timber is used for furniture, cabinet works, buildings, agricultural implements, carriages and wheel works. The timber is also used for railway sleepers, musical instruments, hammer handles, shoe heels and tobacco pipes.
The leaves and shoots are used as a fodder for sheep, goats, and camels. The wood and the dried fallen leaves are used as fuel. The wood of Dalbergia sissoo is classed as an excellent fuel. Calorific values of the sapwood and heartwood are 4,900 and 5,200 kcal./kg., respectively. The wood is also suitable for making charcoal.
Dalbergia sissoo is also known for its medicinal value. The decoction of the leaves is used in gonorrhea, and the leaf mucilage mixed with sweet oil is applied in excoriation. The timber yields oleoresins and essential oil. The roots possess astringent property.
Due to its hardy nature the Dalbergia sissoo is a potential tree species for the afforestation of wastelands like saline and alkaline lands, mine spoils and eroded lands (gullies and ravines). It is also used in the rehabilitation of degraded woodlands.
Reasons behind Declining Population of Dalbergia sissoo:
There are several reasons behind the declining population of Dalbergia sissoo in the Indo-Gangetic Plain of India. The first and foremost is the sudden attack of a fungal disease known as 'dieback' of sissoo caused by Deuteromycetous fungus Fusarium solani f. sp. Dalbergia. This threatening disease has caused large scale mortality of sissoo trees in the last two decades in the region, growing on private and public lands. The F. solani f. sp. dalbergiae often in conjunction with soil-borne Basidiomycetous fungus Ganoderma lucidum parasitizes the roots of Dalbergia sissoo tree as a result of which the roots die ultimately leading to the death of the whole tree.
In addition to this, the persistence of the ‘powdery mildew’ disease of sissoo in the region caused by an Ascomycetous fungus Phyllactinia corylea weakens the trees making them susceptible to other diseases and pests ultimately resulting into their death.
The indiscriminate harvesting of Dalbergia sissoo trees (planted on public and private lands) to meet the need for timber has also been a reason behind the dwindling population of Dalbergia sissoo in the Indo-Gangetic Plain region of India.
The trees of Dalbergia sissoo have reduced to a serious extent on the verdant protected main campus of Banaras Hindu University spreading over 1,350 acres of land area in Varanasi District of eastern Uttar Pradesh. However, in the decades of the eighties and nineties of the 20th century, there were large numbers of Dalbergia sissoo trees on the university campus found along roadsides, in gardens, residential compounds and in the department compounds.
However, the onslaught of ‘dieback’ disease in the last decade of previous century has caused large scale mortality of Dalbergia sissoo trees on the Banaras Hindu University campus consequently most of the older trees have died. Today Dalbergia sissoo is neglected tree species in the plantation programs of the university campus. Since 1997 special priority has been given to the plantation of Terminalia arjuna on the campus.
In addition to this, other tree species included in the plantations program of the university campus are Tectona grandis, Mangifera indica, Azadirachta indica, Millettia pinnata, Melia azedarach, Tamarindus indicus, Senna siamea, Bauhinia racemosa, Bauhinia purpurea, Bauhinia variegata, Sterculia alata, Grevillea robusta, Alstonia scholaris, Jatropha curcus, Madhuca longifolia, Terminalia bellerica. Acacia auriculiformis, Cassia fistula, Delonix regia, Syzygium cuminii and Calliandra haematocephala.
However, the onslaught of ‘dieback’ disease in the last decade of previous century has caused large scale mortality of Dalbergia sissoo trees on the Banaras Hindu University campus consequently most of the older trees have died. Today Dalbergia sissoo is neglected tree species in the plantation programs of the university campus. Since 1997 special priority has been given to the plantation of Terminalia arjuna on the campus.
In addition to this, other tree species included in the plantations program of the university campus are Tectona grandis, Mangifera indica, Azadirachta indica, Millettia pinnata, Melia azedarach, Tamarindus indicus, Senna siamea, Bauhinia racemosa, Bauhinia purpurea, Bauhinia variegata, Sterculia alata, Grevillea robusta, Alstonia scholaris, Jatropha curcus, Madhuca longifolia, Terminalia bellerica. Acacia auriculiformis, Cassia fistula, Delonix regia, Syzygium cuminii and Calliandra haematocephala.
Conservation:
The conservation of Dalbergia sissoo can be achieved by effective control of the diseases like 'dieback' and 'powdery mildew', and also by putting a strict ban on tree harvesting in Indo-Gangetic Plain region of the country. Besides these, Dalbergia sissoo must be given top priority under the Social Forestry Programmes of the region.
The deep rooting habit and nitrogen-fixing attribute of Dalbergia sissoo makes it a potential tree species for agroforestry. Therefore, the inclusion of Dalbergia sissoo in the agroforestry system will be helpful in increasing its population.
Conclusion:
The fast-declining population of Dalbergia sissoo in the Indo-Gangetic Plain of India is a matter of serious concern and needs immediate attention to conserve this valuable tree species for the fulfillment of the needs of timber, fuel, fodder, and medicines and also for the maintenance of ecological balance.
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Dr. Arvind Singh is M. Sc. and Ph. D. in Botany with an area of specialization in Ecology. He is a dedicated Researcher having more than four dozen of published Research Papers in the Journals of National and International repute. His main area of Research is Restoration of Mined Lands. However, he has also conducted Research on the Vascular Flora of Banaras Hindu University-Main Campus, India.keywords: sissoo tree, sissoo wood, sissoo tree information, sissoo wood price in india, sissoo tree picture, dalbergia sissoo tree information, dalbergia sissoo medicinal uses, sheesham wood, rosewood tree, indian rosewood, indian rosewood tree, what is sheesham wood, state tree of west bengal