Casuarinas can protect our coasts fron tsunamis

Suhardi, Yogyakarta

Sukristijono Sukardjo was correct when he wrote in his article published in The Jakarta Post of April 28, that planting mangroves and casuarinas (Casuarinas equisetifolia) can prevent damage to coastal areas and help absorb the power and damage of a tsunami.

Research that this writer and a team from Gadjah Mada University (UGM) once conducted in the southern coastal area of Yogyakarta showed that casuarinas, locally known as cemara udang were more suitable, particularly for open and sandy coastal areas, than mangroves. Sand areas are the most predominant land type in the country's close to 110,000 kilometers of coastlines.

One example of how casuarinas are essential is Lhok Nga beach. The writer recently visited this area and found that mangroves alone were not suitable for planting because they needed special requirements to grow, most importantly that the coastal area is muddy. The best combination of plants for this area would be mangroves and casuarinas.

For many years, the writer and the UGM team conducted research and planting experiments with casuarinas from Madura, East Java, on the beaches of Samas and Pandan Simo in southern Yogyakarta with impressive results. This was particularly so after planting this particular species was later undertaken in cooperation with the Indokor Indonesia Group, a company engaged in developing an integrated shrimp-farming industry in cooperation with local farmers in areas around these beaches.

In 1995, sand areas extending from Samas to Pandan Simo were largely barren. Sand dunes were always changing and rolling over themselves, hot gusty winds blew through the area and little or no vegetation grew in a large territory that extended about a kilometer inland from the beach. The power of the strong sea breeze could be felt up to five kilometers away.

It was very difficult to grow anything on these sandy spots, which were increasing in size, because of their high salt content; salt blown up from the sea by the winds. Many attempts had been made to cultivate the land but to no avail. Agricultural areas continued to be pushed back farther and farther away from the beach.

Research and experiments coordinated by Prof. Sutikno of the UGM School of Geography and by this writer discovered that an organic wind-barrier was necessary and that the casuarina from Madura, East Java, were the most suitable species to create such a barrier.

We began, with the villagers and the help of the Indokor Indonesia Group, to plant the species.

About five years ago, the shape of the coast underwent a dramatic change and the sand began to stop moving. The wind no longer blew in such a way that it caused the sand to move.

Cattle began to come closer to the beach and people began to use the beach areas to expand their agricultural areas.

Locals began grow shrimp casuarina, which can now be found in the yards of almost every home bordering Samas Beach. Trees are now able to grow along the coast making the area less dry and hot.

While before, the shrimp farms of PT Indokor Bangung Desa and the farmers' shrimp ponds were often troubled by dusty and sandy winds and sea water contamination, they are now in much better shape. Vegetables and fruit trees can be grown in the areas around the shrimp farms and better ponds are being developed.

Earlier Indokor's shrimp farms and those of local farmers that Indokor helps--involving investments worth tens of billions of rupiah-- were near collapse because all the vegetation in this area had died.

It is important that efforts to prevent sea water contamination and damage to ecosystems and the environment are carried out not only by UGM, by regional administrations and such private companies as Indokor but also by the environment ministry.

Damage to the environment is a problem not only on a regional scale but also on a national and sometimes an international level. An obvious example is the tsunami disaster that hit Aceh, North Sumatra and Nias.

Casuarinas can now be found stretching continuously from Samas Beach to Pandan Simo Beach, continuing nine kilometers to the west from the Oya River estuary to that of the Opak River. As a result, about 200 ha of land, previously underdeveloped and useless, has now become productive.

Cattle breeding has developed rapidly; an important source of nutrients to sandy areas that are poor in organic substances. Those who raise cattle in coastal areas also have the advantage of having to spend less money on chemical fertilizers.

The increasingly fertile southern coast ends up providing employment opportunities. Indonesia has a total length of 81,000 km of sandy coastal areas which could be developed.

Obviously Indonesia's coastal areas have also faced tsunami and storm threats.

If lines of casuarinas are planted, they can serve as natural "citadels" that protect coastal people by acting as buffer zones that absorb some of the impact of the waves. As well as being an important source of food and income, the many animals that begin to flourish in these areas can also act as important warning systems for possible earthquake and tsunami threats.

Unusual animal behavior was witnessed before the earthquake and tsunamis that hit Aceh, Sri Lanka and Thailand. Planting casuarinas and other suitable trees in coastal areas, also means these animals are protected too.

Casuarinas and other coastal vegetation can grow alongside mangroves in river estuaries and in calm areas behind islands. Shrimp casuarinas can protect previously open beach spaces, spots most vulnerable to tsunamis.

Indonesia has a total of 20 million ha of coastal areas and if these areas are properly managed they could be developed in many ways; into agriculture, shrimp farming, fish farming and tourism.

Once casuarinas become established in coastal areas, other species of vegetation, which were earlier unable to grow can flourish.

Planting casuarinas on coasts would also allow agricultural areas to be expanded without the need for large-scale forest destruction.

There are other possibilities. Vegetables and fruit can be grown, fertilizers can be created from animal dung and shrimps can be grown in a more efficient and environmentally friendly manner.

In this way, the introduction of a combination of coastal species in a planned manner can empower local communities and increase the general welfare of Indonesians.

The writer, a professor at the UGM School of Forestry, is a former director-general of soil rehabilitation and social forestry and an expert adviser at the National Food Security Council.