REFORESTATION IN SARAWAK

RIOR TO THE INDUSTRIAL REVOLUTION in Europe, it is estimated that there were some 6 trillion trees on the planet. In a relative blink of an eye, we have reduced this to 3 trillion. Of most concern is the fact that net forest clearance globally is still running at 20 billion trees per annum and this does not include those areas destroyed by wildfires and other natural disasters. Virtually all climate scientists and the United Nations agree that, to combat global climate change, we must reduce carbon dioxide emissions and most vitally replant our indigenous forests as fast as possible, in addition to halting continued forest clearance for agriculture and other human activities.

It has been estimated that planting one trillion trees would, over time, eliminate two thirds of all of the emissions pumped into the atmosphere by humans since the industrial revolution began. With a planting cost of about $2 per tree, the total cost would be US$2 trillion (or about RM8 trillion). This sounds a lot of money but when taken in context it is not such a great amount when one realizes that the world spends this amount annually on defense! Is not the safeguarding of our planet for present and future generations more important than vast spending on military hardware? What value do we want to place on defending our planet for future generations? With determination, political and social will, and not that much money, this task could be achieved relatively easily.

It is in the wet tropics, supporting lush and highly diverse ecosystems, that the greatest opportunity lies for the carbon sequestration that is so desperately needed to reduce levels of atmospheric carbon dioxide. Indigenous trees in the wet and monsoonal tropics are key – the basic skeleton than can sequester carbon about three times faster than in temperate areas. The great wet tropical forests of Amazon, West Africa and Southeast Asia are carbon sinks which can mop up and render harmless the excessive emissions that human activities have created and restore the relative equilibrium that we have enjoyed since the last Ice Age. Borneo, the Indonesian Archipelago and New Guinea are vital habitats at the heart of the Southeast Asian system.

Historically, reforestation in Sarawak has been largely constrained by the lack of dependable quantities of suitable planting material. The primary skeleton of Borneo’s forests is species of Shorea. Aside from being one of the most important sources of hardwood timber, several species of Shorea produce the highly sought after ‘illipe nuts’ – locally called tengkawang and teglam – a source of valuable fat used in the manufacture of chocolate, and for cosmetics (lipsticks, etc.). As recently as the 1970s, the irregular but mass seeding of Shorea produced a great financial windfall for the rural people of Sarawak who sold the oil-rich nuts to companies like Unilever who sent over mobile processing plants to extract the butter, which was highly valued, most particularly in chocolates. That trade has now mostly vanished, at least partly because so many of the shores have been removed for timber.

We have been working for the past decade to try to solve the problems of planting material supply and we have now successfully developed two techniques which maybe hold the key to resolving these issues. Of course the collection of seed when available would also be vital but Shorea species do not seed annually and seldom in the vast quantities required to support major reforestation.

First, we have developed a method to produce rooted cuttings of several species of Shorea, including representatives of the Engkabangs (species for fat nut production), and the Merantis (the primary source of high quality timber). The method involves taking appropriate cuttings from mother plants and rooting them, after they are dipped in hormone gels, in mist houses that keep the cuttings stress-free over the several weeks/ months that it takes for them to start producing roots and shoots. Generally these cuttings seem to root most readily in perlite but we are looking at other substrates as well. Thereafter the rooted cuttings can be transferred to a more balanced and nutrient sufficient growing medium and then acclimatized in shaded, moist nursery sheds prior to being prepared for planting into their permanent positions.

Normally it would take up to a year to produce, from an initial cutting, saplings that were ready to be planted back out into reforestation projects. However, there is some considerable variation in the effectiveness of producing viable cutting material. While some species are rather slow, there are others that appear to be recalcitrant when it comes to producing rooted cuttings.

A second and very reliable method of producing planting material can be achieved from ‘harvesting’ the seedlings of appropriate trees that occur in the understory of remnant forest. These so called wildings are the offspring of previous flowering and fruiting of mature trees, often carpeting the forest floor beneath their parents. So often, these wildings go completely unnoticed and just form part of the green mass of plants that litter the forest. The vast majority of these seedlings will not survive anyway because their parents continue to shade out their offspring, which eventually wither and die. With special care, these wildings can be readily harvested and relocated to customized mist houses where they will recover and re-shoot to relatively rapidly produce very viable new planting material. In practice, over 80% of the wildings will survive this harvesting process and, within six months to a year, yield viable and robust new planting material. This method can be used, so far as we have been able to determine, for nearly all of the shoreas in Sarawak.

We have used this planting material for experimental plots to test growth rates and tolerance to various levels of shade/sunlight. What has become transparently clear from our trial plots is that several species of shoreas, which are also extremely valuable hardwood trees, are extremely fast growing and the popular myth that all Sarawak hardwoods are very slow growing is just that – a myth. Such indigenous trees conserve soils, reestablish local ecosystems, restore forest habitat for indigenous wildlife and by restoring native forests encourage ecotourism. They can easily match the growth rates of the potentially ecologically damaging foreign trees like Acacia and Eucalyptus which produce effectively sterile habitats and are potential fire risks, as has been so dramatically and tragically shown in the recent Australian bush fires.

An important and rather interesting initiative we are trying is to establish indigenous trees underneath existing oil palm to determine if it is possible to seamlessly convert oil palm plantation back to indigenous forest, or develop agroforestry systems in which oil palm is grown together with high value indigenous timber. Such systems would be more sustainable and provide the opportunity for another income via carbon credits, a system that enables money to flow from the developed and high carbon emission world to the tropics. Indeed it would appear that very soon a tidal wave of investment of this type is on the horizon and Sarawak will be very well placed to take advantage of this seismic shift in global investment that is more focused on carbon sequestration and hence climate stability.

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Dr Timothy Hatch came to Sarawak in 1977 and has really never left. His background is in Agriculture but he now devotes all his time to reforestation issues and projects and administers a Facebook page called Rescuing Borneo.