This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain.

Role of Riparian Vegetation in 1

Bashir H. Shah 2and John L. Thames 3

Abstract.--Pakistan is poor in resources, and exploits all possible sources of to fulfill its needs for fuel, timber and other wood products. Riparian species are a major source of wood in many parts of the country, par­ ticularly in the province of Sind. The important riparian species in the country are Acacia arabica, sissoo, spp., Salix sp., alba, euphratica and other Populus species.

INTRODUCTION classified as protective forest lands. Some of this area is in steep topography in the more At the time of independence from British rule humid, northern part of the country, but the and the separation from India in 1947, Pakistan greater portion is in the arid, semi arid prov­ was apportioned only a small area of productive inces in the central and southern parts of the forest land. Whatever was available, was over­ country. These dryland are primarily com­ exploited to meet the immediate and heavy demands posed of Prosopis, Acacia, Ziziphus, and Capparis created by the influx of refugees and the growing species and various shrubs. These and needs of development. The forest lands which fell shrubs have no commercial value but are exploited to Pakistan were mostly confined to the northern for fuelwood and fodder by local people (Sheikh hilly portion of the country with some irrigated 1977). and riverine forests in the south. Of the total national forest area, about 7 The total area of the country classified as percent is in the inundation plain of the Indus forest land and administered by the Forest Depart­ river (Amjad 1982). Most of these riverine forests ment has now been increased to the extent of about are located in Sind province in the south and are 4.3 million hectares, almost 5 percent of the total the major source of wood products for the province. land area of the country. The increase is partly In a country poor in forest resources all possible due to avenue plantings along roads, canals, and sources of wood are exploited. Riparian vegetation railway lines and to the establishment of irri­ is an important source of wood not only in ful­ gated plantations in barrage zones. Major addi­ filling national needs but also in fulfilling the tions were made by the appropriation of unclassi­ needs of local populations. The purpose of this fied and privately owned lands. However, less is to review the role played by riparian than one half of the national forest area is vegetation, primarily that along the , classified as productive. in meeting these needs.

The present forest lands are not sufficient to meet national and local demands for wood and THE INDUS other fonest products. The deficiency must be fulfilled from private farm forests and by imports. The Indus is the principal river in Pakistan. The remainder of the national forest area is It originates in the Himalayan Ranges within India and enters Pakistan from the northeast. Passing through the Himalayans it receives the Kabul river 1 Paper presented at the North American at , and after passing through the Salt Riparian Conference [Universjty of Arizona, Tucson, Ranges to the south of the Himalayans it enters April 17-18, 1985]. the arid Indus plain at Kalabagh. The major 2 tributary rivers, Jehlum, Chenab, Ravi and Sutlej, Bashir H. Shah is Research Assistant, Uni­ also originate in the Himalayans and join at versity of Arizona, Tucson, Arizona. Punjnud near Multan. In addition to small tribu­ 3 John L. Thames is Professor of Watershed taries, the Indus also receives the Kurrum and Management, University of Arizona, Tucson, Arizona. Gomal rivers from the west from Kalabagh. The

482 The river flows 1250 km southward through the Indus succession in the plain begins with plain and enters and near . the pioneer species, elephant grass (~ ele.­ phantina). This is an aquatic plant that invades In the northern part of the Indus plain be­ newly deposited but permanently submerged alluvium. tween Kalabagh aud Punjnad the river has incised It commonly grows in the water near the banks of a narrow flood plain 24 km wide and 450 km long. shallow streambeds. As sediment from successive The western edge of the flood plain is adjacent is trapped by the grass, the alluvium is to a high, alluvial plateau and the eastern edge raised to a level where flooding only occurs during is bounded by the sandy . Within these the monsoon season. At this stage, elephant grass confines, the river continuously changes its path is replaced by Saccharum spontaneum, a tall grass and divides and subdivides into branches, which which reaches a height of 2 m. If deposition reunite to form a braided system. The new alluvial continues the site is invaded by dense thickets plains so developed are invaded by pioneer plant of Tamarix dioica. This shrub species has single species followed by several stages of plant suc­ stems, which are seldom greater than 3 em in dia­ cession which reaches a typical climax riverine meter, and grows to a uniform height of abo.ut 2 m. forest with the passage of time. Eventually these Successive sediment deposits may build the alluvium forest areas are eroded and engulfed by the river. to a level where internal drainage will allow tree Sediment is deposited on the opposite side forming growth. The site may then be occupied by the climax huge side bars which result in the formation of species Acacia arabica, euphratica new fluvial plains. The formation of fluvial and Tamarix articulata. Prosopis spicigera and the plains by erosion and deposition is a regular shrub like tree, Salvadora sp, may occupy the feature of the Indus. Because the river is con­ margins between the riverine forest and the sub­ fined by the high lands on both sides of the flood­ tropical thorn forest. If tree species do not plain, the area is inundated annually during the invade the site, or are removed, the tall grass, monsoon season of July and August. Saccharum munja, will dominate the site.

Below Punjnad, the river enters the southern The riparian vegetation of the northern flood flood plain in Sind Province where the topography plain has a composition similar to that of the is flat. Due to the annual deposition of large southern plain but with the absence of Acacia sediment loads, the level of the riverbed and the arabica. This tree is not frost hardy and is areas immediately adjacent have been slowly raised supplanted by , an introduced above the surrounding plain. The results in the species that withstands cold temperatures. This past were annual floods which caused heavy loss tree is valued for fuel and timber and is planted of life, property and agricultural crops. in irrigated plantations.

About 100 years ago levies were constructed on both sides of the river roughly 24 km apart for USES AND MANAGEMENT OF RIVERINE SPECIES a distance of 800 km to contain the river during the flood season. This has created a condition The riparian vegetation of the Indus and its in the southern flood plain very similar to that tributaries helps in stabilizing river banks and of the northern portion and with similar plant providing habitat for . However, nearly communities. every component of the community has value in fulfilling some human need, and ingenious uses This 24 km by 1250 km flood plain was the main of the materials provided by each of the riparian source of food, fodder and wood for local popula­ species have developed over the centuries. tions for many years. The moisture retained by the clayee alluvial soil from the receding flood Principal Species water was sufficient to mature winter crops of wheat, grain, lentils, peas and oil seeds. The Acacia arabica is the principal commercial same agricultural practices continue today. How­ tree and the dominant species in the southern ever, the greater portion of food production is riverine forest. The management system used with from irrigated . Extensive irrigation the species involves clear cutting on a 20 year works of reservoirs, diversions, and canals have cycle followed by broadcast seeding toward the end now been constructed along the river. Rainfall of the monsoon season when the river is receding. varies from about 250 mm in the northern portion This is a fast growing multipurpose tree used for of the plain to 150 mm in the southern portion. the production of timber, fuel and other wood pro­ ducts and is the main source of mine props for the country. The bark is used for tannin and the gum THE RIVERINE FORESTS OF THE INDUS is collected for a variety of uses. It is a very good browse species and the foliage is also used The principal species of the southern flood during the dry season as fodder for camels and plain are Acacia arabica, Prosopis spicigera, goats. The animals, particularly goats, prefer Populus euphratica, Tamarix articulata, Tamarix the pods and help both in the disemination of dioica and Salvadora sp. In many areas these trees seeds and in their germination. La~ge herds of may form a fairly complete canopy 12-15 m high in goats are encouraged in the area partly for this which Acacia arabica usually predominates with purpose. The seeds have hard coats that otherwise varying amounts of Prosopis spicigera. Populu~ must be treated with acid or boiling water if used euphratica is usually present in the drier areas. in artificial regeneration.

483 Dalbergia sissoo is the principal commercial Typha elephantina is prized for its soft, species in the northern riverine forests. The tree fluffy which are 2 to 3 em broad and more reseeds naturally but is also planted extensively. than a meter long. Because of their softness, Seedlings are grown in the nursery for one year the leaves are used throughout Pakistan on sleep­ where they attain a height of about one meter. The ing cot beds. The fibers are also used for mats, stem is then pruned off about 2 em above the root baskets and strings for cots. crown, and the root-shoot is used for outplanting. Plantings are made on the edges of excavated, boot shaped pits at spacings nf 4.6 m. The pits are Riparian Vegetation of the Indus Tributary System about 10 meters long, a foot or so wide and one foot deep. Their purpose is to retain water and In addition to these typical Indus riverine to assist in natural regeneration by root suckers. forests, grow on the banks of tributary The plant sites are irrigated by hand at the time rivers and stream channels in the northern hill of outplanting. Once the species has been estab­ tract and western mountain ranges. The riparian lished on an area, regeneration by root suckers vegetation of the tributaries plays an important and sustains the stand. Thinnings for role equal to that of the Indu& in providing wood fuelwood are made at intervals of 6 years up to and other products for local populations. The 30 years and at 10 year intervals thereafter up to main species are Dalbergia sissoo, Morus alba, 60 years. The final cut is made at age 60 to , Populas ciliata, Populus euroamericana produce fine cabinet wood and wood for ornamental in addition to Tamarix and grasses. objects. The wood from mulberry and willow support the sporting goods industry, and Populus Minor Species euroamaricana is used in the match industry. The branches of both mulberry and willow are also used Populus euphratica is a fast growing species in basket making. The sericulture cottage industry which provides fuelwood and supplies the wood used depends upon the leaves of mulberry. in lac work, turneries and for handicraft cottage industries. CONCLUSION Tamarix articulata is also fast growing and occupies moist sites. It is a good browse species Riparian vegetation is the main source of wood and supplies wood for fuel, agricultural implements and wood products in one of the four provinces of and also for handicraft cottage industries. the country. It produces wood for furniture, timber, mining props, cottage industry, sporting Prosopis spicigera is slow growing and occupies goods and the match and pulp industry. In addition dry sites in the transition zone between the river­ to wood and wood products riparian plant communities ine and thorn forests. It is a preferred source of provide forage for livestock, fiber for ropes, cor­ fuelwood and timber and is a good source of fodder dages, strings, material for baskets and mats, for camels, goats and sheep. tanning material and gum. In addition, riparian vegetation helps in stabilizing river banks and Tamarix dioica is a scrub species favored for provides habitat for many wild birds and animals. basket making. It is also a good browse species and is used for fuel. In a country poor in wood resources where the people collect leaves, straw and cow dung for fuel, riparian vegetation proves God's gift in fulfilling Grass Species their needs for fuel, timber to construct their shelters, material for their beddings, fodder to Saccharum munja is a good grass for cattle feed their animals and a source of earnings. when in the early growing stage. When mature it produces stems 3-4 meters long which are used as thatching material for roofs of houses and sheds LITERATURE CITED in the villages. The stems are also used for making baskets, woven stools and chairs, and were Amjad, M. and I. Mohammad. 1982. State of the main material used for making writing pens in Pakistan. Special Publi. which are still used by primary school children Forest Economics Branch, Pakistan Institute, in villages. .

Saccharum spontaneum provides good forage Sheikh, M. I. and M. Hafeez. 1977. Forest and both in the early growing stages and at maturity . Pakistan Forest when the grass is about 2 meters tall, it is har­ Institute, Special Publication. vested and stored for livestock fodder for the winter. The grass is also used as short fiber material in the paper pulp industry. About 4,852,000 kg are harvested annually for this industry.

484