Poor water management, urban encroachment and biological epidemics are threatening the sustainability of Tunisia’s oases.
The oases are a source of one of the country’s main agricultural exports – dates. But more than this, they are complex and fragile ecosystems that sustain the towns and cities that have grown around them.
Tunisia’s southern oases not only provide food for people and wildlife that rely on them, they play a key role in the social, cultural and economic life of local communities. People make date paste and filter date juice or what is commonly known as the native beer - Legmi, with which they make vinegar as well. Palm leaves have been commonly used for making beach huts and sun shelters in tourist areas. Mature leaves are made into mats, baskets, crates and fans. Dried, stripped fruit clusters are used as brooms in some rural areas.
Oases also offer shelter for both locals and travelers from the harsh summer sun in the often inhospitable climate. From the ancient camel trains that used to ply the desert sands to modern international tourists who come to admire the culture and beauty of the region, oases draw people together and offer them the chance to relax, recharge, communicate and exchange.
Three types of oases can be found in Tunisia: continental oases, including Tozeur and Kbilli, littoral oases such as Gabes, and mountain oases in towns like Tamaghza. Palm trees grow mainly around naturally watered or irrigated lands in groves of up to several hundred thousand trees in places such as Tozeur, in south-western Tunisia. Intensive agriculture is supported by wells which draw water from the desert aquifers.
Although the main production of oases is dates, the ecosystems support a wide range of agriculture. While date palms form a canopy crop, fruit and citrus trees are cultivated at a secondary level with vegetables and other plants grown at ground-level.
This managed natural system is often irrigated using a technique first developed by Ibnu Al Shabbat (also known as Mohamed Ben Ali) in the 13th century. Ibnu Al Shabbat was a writer and an engineer who contributed to the creation of open surface canals to help distribute water equitably. Farmers in Tozeur and other oases in the south have conserved this method whilst improving efficiency with new techniques and materials, such as plastic irrigation piping and electric pumps.
Despite centuries of human activity in Tunisian oases, intensive agricultural production, combined with increased demands from industry, tourism and urban populations are threatening the sustainability of these ecosystems, leading to potential environmental, economic and social problems.
According to Muhammad Sadok Bel Kadi, a senior researcher who specializes in the arid region protection in the governorate of Kibili, the government has worked to improve water management, as water-use has reached unsustainable levels.
“The Government is very collaborative as far as water economy is concerned. It is providing sixty percent of the expenses of these water management projects,” Bel Kadi said.
However, BelKadi argued that the problem of illegal wells is disrupting the government project. There is an excessive pumping of aquifers by local farmers, hotel owners and industrial factories.
Ali Zuba, the director of the Regional Research Center of Oases Agriculture of Tozeur, also said that the sustainability of Tozeur’s water resources is being threatened by hotels that are making their own illegal wells to pump water. These hotels are not economical in their usage – the consumed water per night in Tozeur hotels may reach 400 liters compared to Kibili families’ consumption, which amounts to approximately 200 liters per night.
However, Zuba remains very supportive of touristic activities in the area.
“Tourism is a complementary sector sustaining hundreds of families,” he said.
The Gabes oases is under particular threat due to industrial factories that are pumping from the water table and going beyond the capacities of the oasis to supply the ecosystem it supports with sufficient water. Fadhel Bakkar, an expert in coastal ecosystems in Tunisia, said that another important problem facing the oasis of Gabes is the arbitrary dumping of waste from households. In addition, anarchic urban planning and a growing population has led to the encroachment of the city into the oasis, he said.
Intensive and unsustainable management of natural resources and increased urbanization is therefore threatening viability of the oases by placing the ecosystems under stress. In particular, the important industry of date farming is at risk.
Among the threats to date palms is the Alvarae worm. Zuba says that while the worm is naturally occurring, their presence should not exceed five percent of the total crop, according to production norms. However today, the percentage of dates affected by the worms is around 15 to 20 percent.
“Cleanliness is very instrumental for the protection against date worms. Experts are striving to eliminate the falling dates in the autumn as well as the rotten pomegranates’ leftovers which may create a contaminating platform for the worms,” said Ali Zuba.
The Oriktex insect, an invasive species originally from Asia, poses another threat to the oases. According to Bel Kadi, the insect was discovered in the Tunisian oases in 1995. Frequently found in the Rjim Maatoug oasis of Kibili, the insect has forced growers to adopt new ways to protect dates from attack, for instance by using netting around the clusters of dates.
Bel Kadi also spoke of the Bayoud threat to Tunisian date production. It is an epidemic caused by the fungal pathogen fusarium albedinis. It started in Morocco and severely disrupted the country’s date production – in the past the top producer in North Africa and has now started to attack the Algerian oases.
“Bayoud has destroyed two thirds of Morocco’s date production. Nowadays Morocco is importing dates from Tunisia. Before, the country was ranked as the biggest producer of dates,” said Bel Kadi.
Since the 2011 revolution, experts have complained that the government has not payed much attention to protecting dates from the Bayoud viruses that reach the Tunisian South when date seedlings (cuttings) are smuggled in from Algeria and Morocco through the Tunisian-Algerian border.
Over centuries local communities have developed their own lifestyle in the oases built around the harvesting of date palms. Their challenge today is to develop equitable and sustainable practices for resource management to preserve the rich heritage of their way of life.