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The Balinese Landscape

The island of Bali emerged from the seas in a series of cataclysmic volcanic explosions two to three million years ago-just the blink of an eye in geological time-and has been in the process of growing and changing ever since. A relatively minor eruption of Mount Agung in 1963, for example, blew out one billion cubic metres of matter, blasting away the top 130 metres of the volcano in the process, and depositing lava and ash over many parts of the island. Periodic explosions such as this one can literally change Bali's landscapes almost overnight.

Thanks largely to its turbulent origins and relative youth, Bali manages to cram an astonishing range of landforms into a fairly tiny area of just 5,500 square kilometres. The most obvious feature of the landscape is the sinuous backbone of volcanoes which runs the length of the island from east to west. Two other major regions, the lowland plains and limestone fringes, each play a vital role in Bali's unique topography.

Young Mountains and Ancient Reefs

Bali's volcanoes are dominated by Gunung (Mount) Agung in the east, which at 3,014 metres is still by far the tallest peak on the island, despite its recent dramatic shortening. West of this, the adjacent peaks of Mount Batur and Mount Abang are 1,000 metres shorter than Agung.

Along the northeastern flanks of Agung, around the diving spot of Tulamben, spectacular lava flows from the 1963 eruption spill into the ocean, forming the most recent addition to Bali's landscape. The stark scrub vegetation found growing over the dark lava here give an indication of what the entire island may have looked like when it first emerged from the sea.

Mount Batur, at the centre of the island, nestles dramatically in the midst of one of the world's largest calderas beside a huge crater lake. Tongues of lava fan out from the central cone of the volcano, many of them resulting from different eruptions at very different times. The more recent flows are still black and unvegetated even after several decades of exposure to the elements, while the earlier ones are already brown and overgrown.

The outer slopes of the massive Batur caldera, which form much of central Bali, are scored by deep ravines with precipitous sides that have been cut by rivers running through the soft tuff rock, a common feature throughout the island. Continuing to the west, the mountains separating Lovina from Negara are also of volcanic origin, but date from a much earlier era, so their craters have long since disappeared; the only sign of their volcanic origins is a few sulfurous springs which dot the region.

North and south of Bali's volcanic backbone lie the coastal plains which form Bali's rice bowl. Most of Bali's lowlands, and certainly all the fertile parts, have been formed by deposits from numerous volcanic eruptions. Along the coasts fringing the lowlands are black sand beaches consisting of fine volcanic particles. By contrast, other beaches such as the one at Sanur, are lighter in colour and composed of rough volcanic and coral particles mixed with the shells of countless billions of marine organisms.

Several parts of Bali meanwhile are non-volcanic and stand in sharp contrast to the rest of the island. These are the limestone (fossil coral reef) areas of the southern fringe, chiefly at Negara in the west and on the Bukit Peninsula south of the airport, where the luxury hotels of Nusa Dua are located. Like many limestone regions, these areas have poor soils and are difficult to cultivate.

The Human Side of Bali's Landscape

For all the rugged natural beauty of many of the wilder parts of Bali-the volcanoes and lakes, lava fields, forests and seashore cliffs-the overwhelming impression is of a profoundly humanised landscape. People probably first arrived on Bali between three and four thousand years ago and have been moulding the island to meet their needs ever since.

The most striking manifestation of this is the intricate patchwork of innumerable rice fields which covers many parts of the lowlands and climbs the hills and lower slopes of the mountains in tier after tier, creating one of the most harmonious and beautiful meldings of the natural and the man-made on earth. Bali's rice fields represent one of the most sophisticated and stable examples anywhere of a traditional agricultural system, a system which has been in place for nigh on a thousand years and which has much to teach modern-day farmers elsewhere.

Nestling part way down a ravine, a farmer's house is surrounded by fruit trees.

The Ayung River, Bali's largest, cuts through soft volanic rock to form a ravine so typical of the terrain around Balis central volcanoes.

Rice is more than just a staple food for the Balinese; it is a cultural and spiritual lynchpin whose cultivation has had a profound influence on the structure of Balinese society. It is even personified as a deity, the goddess Bhatari Sri. The commonest form of rice cultivation on Bali is the wetland or sawah system of flooded fields, where the water is retained by low banks or bunds. Most sawah fields may be watered by irrigation; the seasonal nature of the rainfall on Bali, especially at lower altitudes where the rice is grown, means that a scant one per cent of the 100,000 hectares or so of sawah is rain fed.

Almost 20 per cent of Bali's land is devoted to another traditional form of cultivation-the kebun or home garden. These are an intricate, mixed-cultivation system in which as many as 50 different crops of all shapes and sizes may be grown. The tallest trees are generally durians or coconuts, below which grow other fruit trees such as rambutan, jackfruit and mango, providing a lush, dark-green canopy. Also important are the nutritious papaya and the ubiquitous banana, grown not only for its fruit and edible stem but for its leaves, which have a thousand and one uses. Interplanted with these are tall ground crops such as maize and cassava, while nearer the soil are other vegetables such as taro, various spices and scrambling sweet potatoes. There are also climbers such as yam, passionfruit and melons, which can reach up into the tops of the tallest trees.

The kebun helps to ensure that Balinese families can enjoy a varied and nutritious diet, for at any given time of year, a wide range of crops will be ready for harvest. It is not, however, just a kitchen garden, for the system is increasingly used to provide crops for sale within Bali and for export. Notable amongst these are coffee, cloves, vanilla and even the Hydrangea flowers which are used in Balinese votive offerings, all of which flourish in the shade of the larger trees in the kebun.

The fertile and well-watered volcanic areas of Bali support luxuriant foliage and excellent conditions for agriculture. Balinese cows here plough a flooded rice field in preparation for the young seedlings.

Water is considered to he sacred in Bali. A bamboo conduit carries water here from a sacred spring; it is then collected to be used as holy water in temple ceremonies.

The emerald-coloured grass growing up the walls of the rice terraces contrasts with the ripening heads of rice.

Variations in colour from green to gold reflect the different stages of plantings of the all-important rice; a surprising 99 per cent of Bali's rice crop is grown in irrigated fields.

The sawah and kebun apart, one of the most distinctive features of the Balinese landscape are the enormous fig or Waringin trees which grow along the roads, close to or in temples. These magnificent trees are extremely important to fruit-eating birds and insects since they bear numerous small sweetish fruits.

Wild Rivers and Mountain Lakes

With its mountainous topography and heavy seasonal rainfall, it is not surprising that Bali has more than its fair share of rivers and streams. What is surprising, for such an apparently lush island, is that only about half of Bali's 162 named rivers and streams flow year round; the rest hold water only during the rainy season, normally from November to April.

The heavy monsoon rains create a powerful flow of water which cuts easily through the soft volcanic rocks; thus, most of Bali's rivers and streams flow in the bottom of deep, steep-sided valleys or ravines until they reach the coastal lowlands. Most rivers are short, flowing for less than 30 kilometres.

Bali's lowlands are singularly devoid of natural lakes. However, several are found in the central part of the highlands. By far the largest, most spectacular and most important to the Balinese is Lake Batur, covering just over 1,700 hectares in the ancient caldera surrounding Mount Batur. Some 30 kilometres to the west of Lake Batur are three much smaller but still impressive crater lakes at similar altitude: Lake Bratan, Lake Buyan and Lake Tamblingan. These were probably once a single lake before lava flowed across it, isolating one body of water from the next. Tamblingan is the least disturbed, most beautiful and most remote lake, while Bratan and Buyan have extensive areas of market gardens around their shores.

Lying within a vast caldera at the island's centre, Batur is Balis biggest lake and the source of an underground network of water channels which feed into sacred springs all up and down the slopes of Mount Batur.

Lake Tamblingan and Lake Buyan, seen to the far left, are thought to have once been a single lake which was later split in two by a lava flow.

The landmark temple, Pura Ulun Danu Bratan, dedicated to the goddess of Lake Bratan, lies within another volcanic crater to the west of Batur.

Fertile Bounty of Bali's Volcanoes

The soft volcanic rock and ash of the mountains are easily weathered and broken down to make a thick layer of finely textured topsoil which is generally rich in minerals and extremely fertile. In addition, the topsoil is very well drained, ensuring that there is little risk of flooding; yet it is also highly prone to leaching, as the rain easily washes out minerals. The soils at higher altitudes are particularly susceptible to this, as their only source of water is from the atmosphere. Soils lower down benefit from the loss of those further up, as they are enriched by minerals carried down in streams and irrigation water. Counterbalancing this, the soils at higher altitudes tend to be younger and thereby intrinsically more mineral-rich and fertile than those lower down. The older, low-lying soils have gradually lost their minerals over the years, resulting in an acid, kaolin-rich clay.

Leaching is most marked in wetter areas. In seasonally dry regions, evaporation from the soil tends to pull dissolved minerals up through the soil, thereby maintaining fertility. However, clay soils are sticky and hard to work when wet, as hard as concrete and cracked when dry. Thus, plants and farmers in different parts of Bali are faced with opposing problems: either there is adequate rainfall and a constant battle to maintain fertility, or reasonable fertility but highly seasonal rainfall and difficult soils. However, the clayey quality of much of the soil allows the construction of stable terraces on precipitous slopes which, in many other parts of the world, would pose a severe threat of erosion. The terraced bunds made of Bali's sunbaked clay can be almost as hard and stable as brickwork although they nevertheless require a good deal of maintenance.

The white sand beach at Nusa Dua, with the towering cone of Gunung Agung visible in the background.

The spectacular cliffs on the west side of the Bukit Peninsula, near the famous Ulu Watu temple; the shoreline in the distance is East Java.

The dramatic black sand beach at Kusamba, like many around the island, is composed of volcanic particles spewed out from Mount Agung, a still-active volcano. In the background is the island of Nusa Penida.

Bali's rice fields, watered by a thousand-year-old irrigation system, occupy fertile lowlands and volcanic hillsides alike.

The relatively dry land along the northeast coast near Tulamben, was covered in lava flows by the eruption of Mount Agung in 1963, and thus exhibits a very different vegetation from the rest of the island.

Seasons in the Sun

Bali's volcanoes provide the raw material of which the island is composed. However, climate determines to a large extent which plants can grow on these soils. Lying within the moist tropics, Bali seems to visitors to be almost unfairly blessed, with abundant but not excessive rainfall and warm but not overly hot temperatures year round. The true picture is more complex. Despite its equatorial position, Bali's climate is markedly seasonal and shows notable variations from year to year. Moreover, the island's varied topography leads to great regional variations, some areas being much cooler and others more arid than one might expect.

From November to March, Bali has hot and wet weather. The rest of the year is cooler and drier, as the island is influenced by the dry southeast monsoon winds which blow in from the Australian continent during the middle of the year.

Bali thus has three major climate zones: the wet mountains, which receive over 300 centimetres of rain a year and where mosses and lichens adorn the stone of temples and shrines and the vegetation is lush; the lowlands and hills, where the average annual rainfall is about 200 centimetres, most of it falling in the four or five months around Christmas, and the very dry fringe areas at the northern, southern and western edges of the island. Temperatures change with altitude much more than with the seasons, and ground frosts may occur under clear night skies in hollows above 1,500 metres. Lowland daytime temperatures vary little between the dry and rainy seasons, from 28°-29°C to 30°-31°C respectively.

A Thousand-Year-Old System

The farmers of Bali organise their sawah irrigation through subaks, which are autonomous cooperatives of rice farmers who are all dependent on the same water supply. Subaks are socio-religious groupings which are organised through a hierarchical system of water temples, linked ultimately to the great temple of Ulun Lake Batur, the temple of the lake below Mount Batur, traditionally regarded as the source of all irrigation water on Bali. The arrangement of subaks is determined by local drainage and water-flow patterns, so that one village may have members of several different subaks within it. They are responsible for the maintenance of the system of irrigation channels, tunnels and weirs, as well as the instigation of fallow periods and the determination of rice-planting times.

The influence and importance of the subak system was greatly underestimated by the Dutch colonial authorities, an attitude which persisted in the post-colonial era, until a few years ago. For example, the role that coordination of rice-planting times over a wide area plays in the control of certain pests was not appreciated by outsiders until very recently, although it was obviously well understood by the local people for centuries.

Even under optimum conditions, only two rice crops a year are practicable in any one field. To maximise the use of arable land on this densely populated island, dryland crops such as maize, cassava, sweet potatoes, groundnuts and soya beans are grown as part of the rotation under non-flooded conditions after the rice has been harvested.

On Bali, practically every square metre of arable land within reach of a source of irrigation water is under sawah cultivation. Rather surprisingly, this accounts for only around 20 per cent of the island, concentrated in the southern lowlands and in the region of the north around Singaraja. Rather more than this-just under one-third of the island-is given over to non-irrigated or dryland fields which produce just one rain-fed crop each year.

The distribution of arable land and access to irrigation water have had a profound effect on human settlement patterns in Bali. This is perhaps best illustrated by looking at the arrangement of the traditional nine kingdoms into which Bali was divided. Seven of these are concentrated in the fertile region to the south or southwest of Mount Agung and Mount Batur. The drier, narrower north coast and the west, with its extensive areas of infertile limestone, could only support one kingdom apiece.

In modern times, particularly the last two or three decades, there have been profound and far-reaching changes in the distribution of population. The growth of tourism and the beginnings of industrialisation have drawn increasing numbers of people to certain areas, especially along the coast, which formerly supported much lower populations. Land, some of it once productive, is continually being lost to urbanisation. This, along with the ever-growing population, is placing increasing pressure on Bali's fertile soils and traditional agricultural systems.

The procession just seen wending its way through the rice fields is on the way to collect holy water from a spring on Mount Agung.

Vegetation scales right up the flanks of Bali's sacred mountain, Gunung Agung, a volcano that erupted with devastating results in 1963. The outpouring of ash helps fertilise rice fields such as these, which seem to resemble an amphitheatre.

The cooler climate of the highlands above Lake Bratan encourages the growth of Dicksonia sp, although the showy Spathodea campanulata (in the background) more commonly seen in the lowlands still flourishes here.