Introduction

AI Ain takes its name from the historic oasis at the heart of the city. This is appropriate for a city now considered to be the cultural and educational centre for Abu Dhabi Emirate. AI Ain oasis is the largest of the five oases which form the UAE portion of the complex of oases. The oasis is defined by Wadi Sarooj and Wadi AI Ain which form a natural boundary to the south and the modern city which crowds the oasis on the other edges. On the western margin is a palace where Sheikh Zayed resided and which has recently been restored. The suq was the city's main market and is still active on the northern edge of the oasis. The Eastern and Murabba Forts guard the eastern fringe and are more than 80 and 50 years old respectively. The accompanying map indicates the main features of the oasis and its immediate surroundings.

The continued existence of the oasis is due to the key role it played in the past for the people of Abu Dhabi Emirate. It is an important focal point in the national psyche having strong associations with national identity and culture, the country's president and ruler of Abu Dhabi, Sheikh Zayed, and the people's welfare and survival.

The oasis has probably been in cultivation for at least four thousand years. Evidence from Hili 8 archaeological excavations confirm that all the elements of date palm oasis culture were in place in the third millennium BC. There are substantial occupation mounds within the AI Ain oasis but none seems to have been explored by archaeologists, probably the only way of establishing the age of the oasis. However the size and strategic position of the AI Ain oasis would indicate that it was in cultivation at the same time as the Hili centre of civilisation.

Steel gate with hasp and padlock

The water supply is ground water primarily brought to the oasis by aflaj, underground water tunnels that tap aquifers many kilometers away towards the mountains. They are of great antiquity and are the life-blood of the oasis. Aflaj are like trunk water mains, bringing water great distances, preventing loss by evaporation and relying on gravity to make the water flow.

There are two main falaj, the AI Aini and Dawoodi. These approach the oasis from the southeast, respectively passing over (by means of an aqueduct) and under Wadi Sarooj. These supplies are distributed through an intricate network of channels, now mostly of cement or concrete for durability. The rota for water distribution is strictly enforced and is achieved by blocking channels to direct the water to the required area.

The nature and quality of the soil is the reason for the presence of the oasis at this particular location. Elsewhere in AI Ain the ground is composed of sand and gravel. This type of ground was suitable for annual crops such as wheat, barley and vegetables which relied on the winter rains or well water for a limited period of the year. At this location Wadi Sarooj flows around the natural barrier of an outlying rock ridge from Jebel Hafit. Over the millennia, the wadi has brought fine silts and clays to the oasis area, the products of weathering of the mountain rocks to the east and south. The clay ensures good water retention. It is a good base for continuous cultivation and also makes a good building material as can be seen in the original mud brick walls. Excavation for brick making and to level plots, combined with the natural ground contours, has lowered gardens levels well below the paths in places. The paths probably started as raised bunds separating the plots for irrigation purposes and these would naturally be used for access as the ground is very soft when saturated. Over a period of time, the bunds were walled as plot security was established.

There are few dwellings within the oasis. People lived on the fringe as the land was too valuable for cultivation to be used for village space. Living conditions were probably also better outside the oasis with less humidity although the shade would have been welcome. There are a number of mosques spread at regular intervals so that workers could perform their regular prayers.

Female flower spray of date palm (Phoenix dactylifera)

Man's exploitation of the date palm started in the Chalcolithic period. The date palm, Phoenix dactylifera, is indigenous to the hot and dry areas of the Middle East. The date fruit was a mainstay of local nutrition, providing a dependable supply of high energy food with excellent keeping properties. Together with cereal grains, various milks, dried fish and a little meat it formed the basis of the local diet.

The date palm is dioecious, that is there are separate male and female plants. One male palm is sufficient for the natural fertilization of 25-50 female palms. This is the ratio usually planted in date gardens. If you plant a date stone you have a 50/50 chance of getting a female plant and a one in ten chance of getting good fruit. Not very good odds when you may have to wait for five years before the palm bears fruit. Traditionally, propagation has therefore been by means of offshoots which grow at the base of the palm and which are genetically identical to the parent. Wild date palms rarely produce a tall trunk as the offshoots crowd the base of the palm and grow into a thicket, stunting growth. The serried ranks of palms in the oasis are therefore very much a man-made vista. Offshoots are cut from the base of the palm as they develop into miniature palms. For the first 5-20 years of the palm's life the offshoots are removed but a single growth is left at the base of the trunk to encourage more offshoots to grow. If all the shoots are removed, the palm is inhibited from producing any more. In traditional cultivation all the offshoots were removed after about 20 years so that fruit production could be maximized. There are palms of all ages in the oasis and some may be as old as 90 or 100 years. Old palms are regularly removed as they become unstable, bear less fruit and are difficult to maintain as all work has to be done at the head of the palm, up to 24 meters above ground level.

Worker climbing a palm to pollinate it

The sequence of seasonal cultivation starts in the spring, (February/March) with the palms coming into flower and requiring pollination. An average of ten flower buds, called spathes, develop on each palm annually. They are individually pollinated by placing a few spikes from the male spathe into the female flower and loosely binding it to ensure pollen

distribution. As the fruit bunches develop, the supporting stalk elongates so that the fruit bunch will be pendant. They are often tied to leaf stalks to brace them and prevent wind damage. Date production varies from 20 to 100 kilograms per palm per year depending on variety, water supply, crowding and organization of cultivation. By the very end of May the dates are at the khalal stage and are fully developed in size. As they change color to yellow or red, the bisr stage, they become edible with a crunchy texture and rather astringent taste. The dates continue to ripen to the rutab stage, turning brown and softening. Tannins in the fruit are turning to sucrose which will in turn invert to glucose and fructose. As a result there is a balance between the astringent and sweet taste which varies between the different date varieties. The dates are picked for marketing fresh. Premium varieties like khalas have a delicious balance of sweetness and astringency at the rutab stage. Subsequent development is largely drying of the fruit to the tamr stage when the sugar content acts as a preservative which allows the date to be kept in excess of one year. This may take place on the palm or after picking by drying in the sun. Most dates are for human consumption with any poor quality dates being used for animal feed.

Other cultivation requirements during the year include the trimming of old dead leaves and leaf bases which is usually done in two stages and results in the very characteristic appearance of the trunk of the palm, removal of the maturing offshoots and cultivation of the ground around the palms. At the appropriate time of year all these operations can be observed in the oasis.

At the tamr stage a typical date is 15-20% water, 73-80% sugars, 2-6% fiber, 1-3% proteins and less than 0.4% fats.

Dates contain reasonable amounts of vitamins A, 81, 82 and niacin and are a good source of potassium, calcium and iron. There are traces of other nutrients but no significant amount of vitamin C.

Some of the named varieties of date grown in the AI Ain oasis are naghal, khunaizi, khalas, jaberi fardh and hilali. These palms provide a long fruiting season giving an extended availability of fresh fruit and also spreading the work of cultivation, harvesting and processing of the date crop. There are many more varieties in cultivation in AI Ain, perhaps as many as 100 named varieties in AI Ain oasis.

As well as fruit, the date palm yields a number of other useful products. The trunks of felled palms were used as construction timber. The growing point of a felled palm yields a delicious vegetable but as it involves destruction of the palm, is a rare treat. The fronds of the leaves were plaited into bags, mats, food covers, baskets, fans and many other household craft items. The leaf midribs were made into chicken coops and furniture. Whole leaves were bound together into flexible matting called da'an which was used in house construction and which is still popular as a fencing material. The dried fibrous leaf sheath called leef which is recovered as the leaf bases are trimmed, was used to make cordage and for packaging material. The long fruit stalks yield a superior fiber with better strength than leef; this was used to make the climbing straps, called habool, used by the workers to ascend the palm trees. Date stones were used as animal feed. Finally, practically all parts could be used as fuel and the ash used as fertilizer.

Taxes

In the past local rulers created revenue by imposing date taxes and also falaj water rates. Falaj dues were used for the maintenance work required to keep the water flowing. This tax was called naub. The system was rationalized in the early

1950s in AI Ain. Everyone paid a flat rate of one rupee for every three hours of water. The maintenance of the falaj is now the responsibility of AI Ain Municipality who also control the distribution of water through a dedicated aflaj section of their administration.

The date tax was generally one tenth of the crop for falaj watered crops and one twentieth for gardens with water from wells. The crop was measured in various shapes and sizes of container such as jirabs, ghosa and gal'a. In AI Ain the jirab was 70-80 Ibs, whilst in the Liwa oasis to the west of AI Ain on the edge of the Rub al Khali it was 180 Ibs. There was a threshold level called nisab below which tax was not collected from a date garden owner. The nisab was set at 20 jirabs in Liwa in the 1950s. The threshold was therefore nearly two tons in Liwa. Possibly this gives an idea of the subsistence level for annual date supply to a large extended family. In the first decade of the last century the Ruler of Abu Dhabi collected 5,000 jirabs of dates as tax from the Dhawahir tribe in the whole of AI Ain and each jirab was valued at one Maria Theresa dollar. This amounted to 190 tons of dates. Taking into account production from small gardens below the tax threshold and also gardens owned by the ruling family which were exempt, an annual production of 2,000 to 3,000 tons of dates is estimated for AI Ain oasis. The Dhawahir were also obliged to supply 3,000 Maria Theresa dollars worth of lucerne to feed the ruler's horses kept in AI Ain. By the middle of the 1950s the tax on dates in AI Ain was only yielding 1,200 jirabs per annum. Although other factors were involved, this reflects the low point in the general economy of the area at that time.

A Tour Through The Oasis

Oxalis corniculata plant

The points can be combined into a walk commencing at the AI Ain Museum carpark. They are described in the order encountered on this walk which is about 5 kilometers long.

Immediately after entering the oasis through the new gate, there are several sidr trees on the north side of the path (1). The sidr is a native tree with edible fruit called nabaj or sho'ab, rounded leaves and many spines. The fruit is a medium sized berry with a substantial stone in the centre. They are edible when green but can be sour and astringent and are more palatable when they turn yellow or red. The Latin name is Ziziphus spina-christi. It was thought that this tree provided the crown of thorns worn by Jesus as the tree is native in Palestine.

Near the parking area on the north side just inside the entrance (2), the landscaping includes several large ceramic storage jars known locally as kars. The jars were used allover this region to store dates, grain and water.

A short side passage (3) on the north side of the main path shows one of the options which was considered for the recent redevelopment. It leads to three old steel double leaf gates which crowd round one of the main water channel junctions. The walls are finished in a adobe colored cement render to match the mud brick wall finish and the traditional steel gates were retained. Traditions develop quickly in this country! Now take the first side path to your left.

At the T-junction turn left and at the next corner there is a small mosque which has not yet been redeveloped. At the time of writing there was a gourd plant festooned over the wall. Where there was enough light penetrating the palm canopy cultivation of vegetable crops was possible within the oasis. At the next junction turn right to keep heading in a southerly direction.

The first garden on the east side of the path (4) has an old iron- studded wooden gate; a little rickety but still functional. These wooden gates would not have lasted long, as termite infestation would have been the main problem. The gate has a postern door in the left hand leaf. There is one more old wooden gate in a side passage just south of this gate and one has been recorded in use as a channel bridge. Only a few of these old gates remain in the whole oasis. The route reaches one of the redeveloped pathways. Turn right to join this and then immediately left back onto an undeveloped path.

The path widens at this point (5) which has enabled a number of weeds to become established. Lantana is the most vigorous as a low ground cover plant with pink flowers and black berries. It is potentially a serious weed pest. There is a young sesban tree (Sesbania sesban) with attractive pea-type yellow flowers which have a dark red mottling on the reverse of the petals. It has long thin cylindrical pods which persist on the plant. It is usually grown as a fodder plant and was probably introduced for this purpose. It is now naturalized in Arabia. Another common weed here and in the date gardens is prickly chaff flower (Achyranthes aspera). It is low growing with a prominent terminal flower spike of small purple flowers and beneath them the remaining spiny bracts which give the spike a very rough feel. The Arabic name is mahowat and it has several medicinal uses, including use of the whole spike as an expectorant!

Mango tree flower against date palm trunk

Reaching the next junction where you will need to turn left and then right, there are extensive remains of mud brick walling (6). The form of construction with open joints within the wall and an external mud plaster coat is evident.

The path soon joins the developed area and you need to turn left at the next junction and carry straight on where a path joins from the right. The path now turns several times. At the point where the path turns east through ninety degrees (8), there is an open gate into a plot. Propped against the wall on the left just inside the plot is a steel gate with the Emirati flag depicted on it, indicating that it was made after 1971 when the Emirates were founded. Next you reach the limit of current redevelopment and the path widens out as it leaves the palm plantations.

On the north side of the path is a magnificent ghaf tree (9), one of a small number of mature specimens in the oasis. Ghaf, Prosopis cineraria, rarely gets the opportunity to grow without man's interference, most frequently in the lopping of branches to provide fodder and the grazing of lower branches by livestock to produce a very uniform trim. The tree has light foliage which is usually pendant on thin branches. This specimen looks as though it has been left to grow naturally.

At this point (10) we are at the edge of the oasis proper and the route turns right to pass between a farm on the left and date gardens to the right. The farm has been developed to grow field crops, as would have been the custom in the past on the oasis fringes. In the past fodder, wheat, barley, sorghum and vegetables were grown seasonally. If the winter rains were good or there was a good supply of well water, these additional crops boosted the family's resources and potentially gave a surplus for trade or barter.

The path drops down to Wadi Sarooj. At this point (11) there are many specimens of Prosopisjuliflora, an introduced member of the mesquite family of the Americas. I n many places it is considered to be a weed pest and is blamed for hay fever and asthma attacks as it has copious pollen. The pods are however browsed by livestock as they are highly nutritious.

Soon after the point where steps lead down in to the wadi bed (12), on the right hand side the Dawoodi falaj can be observed at a location where access has been provided to the strong water flow. The walk now follows the wadi as it narrows and deepens at a pinch point with high banks on each side. There are many trees established in the wadi bed. Their taproots may be up to 20 meters deep to reach groundwater supplies.

The wadi turns to run northwest and on the right bank (13) there is a magnificent specimen of Acacia nilotica, thorny acacia. It has attractive globular yellow flowers in the winter which are followed by very characteristic pods with constrictions between the seed chambers. The tree is not particularly common in the UAE. Apart from fodder for animals it yields a high quality timber. There is a smaller specimen downstream and another mature specimen near the mosque inside the western gate to the oasis.

After a group of samr trees (Acacia tortilis) on the right side of the wadi, a steep path leads out of the wadi back into the date plantations. At the T-junction turn left; the path wanders round the edge of gardens where you are actually looking down on to the palms due to the level differences.

Fig fruit that has dried on the tree

At a sharp left hand turn in the path (14) there is an extensive thicket of the "toothbrush shrub", Salvadora persica, or rak in Arabic. The mature stems or roots are cut and after peeling off a centimeter of bark at the end, are worked into a fibrous brush which was used to clean the teeth. Bundles of the cut stalks, called meswaq, can still be bought in the market. The chemical constituents help to remove tartar, stimulate the gums, provide an abrasive action and a protective coating. Many parts of the plant were used in medicine and veterinary work and the leaves were used as fodder. The flowers have a smell like coffee and the ripe dark red fruits are edible with a very peppery taste.