Tuesday, June 30, 2009

Rating of forest canopy walkways: 4 stars for Sepilok

I visited the canopy walkway in the Sepilok Forest Discovery Centre in Sandakan last week. The experience is so different from my first walkway, in the 1960’s, that I am moved to attempt a rating of the canopy walkways I have seen in Malaysia.

My first walkway was constructed by local jungle people, the Orang Asli, in Bukit Lanjan forest at the edge of Kuala Lumpur, under the supervision of US Army medical officers. The US team was based at Malaysia’s Institute for Medical Research during the duration of the Vietnam War to study animal-borne diseases that could affect troops in tropical rain forests. While the medical personnel screened the animals of the canopy, I worked on the trees. The walkway was improvised with aluminium ladders for walking upon, suspended by a system of ropes anchored to big trees. The walkway swayed and bounced with every step and one had to keep a firm hand on the ropes to avoid falling out. Whenever an anchor tree died, the walkway had to be realigned through a different set of trees. This interfered with long-term observations on canopy trees. I give the Bukit Lanjan walkway a one-star rating. It no longer exists.

The Bukit Lanjan canopy walkway may have been the first in the tropics. Subsequent walkways have been built with tourists in mind, and the sides are netted so that people cannot fall out by accident.

The Sepilok walkway merits a 4-star rating. It is absolutely steady, on permanent supports of steel and concrete. The work has been done very carefully, with no noticeable damage to the trees and forest. This walkway will not require shifting and is ideal for long-term studies of the forest from permanent vantage points. The walkways are steady enough to ride a motorbike on, and to support camera tripods for time-lapse photography. The forest is truly magnificent for its big trees and diversity of species. At present, users walk to the end and have to come back the same way, but when the last lap is completed, users will do a full circuit. When that happens, the walkway will deserve a 5-star rating.

The walkway at the Belian Camp in the Maliau Basin in Sabah merits a 3-star rating. The walkway is anchored on big trees, but the construction could have been better. The barks of the anchor trees show some signs of damage. Users reaching the end have to come back the same way and there are no plans for a one-way circuit.

The walkway at the Forest Research Institute Malaysia in Kepong also merits a 3-star rating. It is anchored on big trees. The anchoring has been done carefully, with no damage to the trees. Traffic flow proceeds in a single direction. The walkway gets a 3-star rating because although the forest is great, it is not as magnificent as in Sepilok or Maliau.

The walkway on Penang Hill merits 2-stars. It is anchored on trees, and users proceed in a single direction. The forest is a unique coastal hill forest of Shorea curtisii. It gets two stars because the species diversity is low compared to the other sites.

Friday, June 05, 2009

Horticulture in Myanmar

I have just returned from a 5 day tour of Myanmar, during which we visited Yangon (Rangoon), Mandalay and Bagan (Pagan). It was a sightseeing tour, and the sights were worth it. Some of the temples are, in their own way, as impressive as St Peter's in Rome. The roads and hotels are excellent; the people are friendly; street crime is virtually unknown; and the towns, villages and markets are free of rubbish. The vendors do not try to cheat foreigners. We did not see any armed military or police personnel anywhere.

The extent of poverty is high. On our flight back to Malaysia, the plane was filled with young men and women coming to Malaysia to work. They were shabbily dressed, did not know how to use the toilets, and had not bathed for several days. Curiously, on our way there, the plane had been full of returning workers but we had hardly noticed them. They had obviously been changed by their stay in Malaysia.

Horticulturally, the country is still in the 1950s. Almost all the garden plants are old varieties from the colonial period and the diversity is small. For example the most common variety of hibiscus is the variety that Malaysia chose as its national flower in 1957. This variety is now uncommon in Malaysia because of replacement by new imported hybrids. Still, it was nice to see some old garden plants that I have not seen for years.

The countryside in Pagon is semi-arid savannah, with trees spaced out instead of forming a closed forest. Here most of the trees belong to just a few species, notably neem, tamarind, Acacia leucophloea and Borassus flabellifer (commonly known in Thailand and Malaysia as 'sea coconut' though it has nothing to do with the sea and is not a coconut). In Myanmar, the fan-shaped leaves of Borassus are used as thatch for roofing, the inflorescences are tapped for its sugary juice to make a fermented drink, and the fruits are harvested for food. In olden times, Myanmar was part of the 'palm culture' of South and Southeast Asia, in which written records were made on the leaves of Borassus cut into strips and inscribed using a sharp stylus. The strips were sewn into books for safe keeping.

The women in the villages and countryside are in the habit of painting their faces with a yellowish powder made by grinding the bark of Limonia accidissima on a stone surface.

Those wishing to visit Myanmar should be aware that credit cards are useless because of the US and European trade embargo. You need to carry cash in US dollars. One USD can be changed in hotels for 1000 Kyats (pronouced 'Jets' because K is silent and y is pronounced as j). The banks offer only 450 Kyats for 1 USD. Only clean USD notes are accepted. Soiled or torn or faded notes are not accepted.

Monday, May 25, 2009

Horticultural carbon, terra preta and high performance horticulture in the humid tropics

I have received many enquiries about the horticultural carbon that I use to create the rooftop 'Secret Garden of 1 Utama'. To make it easier to deal with queries, I have prepared the following account, to be published in a journal. Please bear with the stiff format and language, which is a journal requirement.

Introduction
Soils in the humid tropics tend to be highly clayey. Clay particles stick together to impede passage of water and air, and this is detrimental to root growth. Without sustained effort keep clay soils open and porous, tropical soils rapidly become unproductive. Growers resort to many different methods of farming on clayey soils. For example, vegetable growers till the soil after each harvest and pile up the loosened soil to form raised beds. During each watering session, water soaks in and drains out easily, thereby simultaneously renewing the supply of water and air in the soil. A good soil is analogous to lung tissue in that both have large internal surfaces to hold moisture and air. Unfortunately the effect of tilling lasts only for a few months.

Clay soil may be burnt over a hot fire, in the process of which it becomes crumbly (Holttum 1953). Burnt soil maintains its crumbly structure for up to one year, and such soil is often used for container gardening.

However, the most favoured soil for horticulture is garden black soil, which goes by the Malay name of tanah hitam (black soil). Black soil originated in household backyards where domestic waste was dumped and periodically burnt. The black colour was due to the accumulation of charcoal and soot in the soil over time.

Tanah hitam in Malaysia seems to be very similar the soil in the Amazon known in Portuguese as terra preta (black earth). Terra preta soils are very fertile and contain a high content of carbon (about 10%). They occur on sites that appear to have been permanent native settlements for centuries before their populations were wiped out by diseases brought in by the Europeans. It would have taken centuries of firewood burning on the same sites to have produced black soil in the vast quantities, to 2 m deep in some sites. The discovery of terra preta sites has created a lot of discussion in the Internet about its origin.

The development of horticultural carbon
Open burning has been prohibited for many years in Malaysia, hence black soil is no longer available. Needing a large volume of good soil to establish a rain forest in the ‘1 Utama’ shopping mall in Kuala Lumpur, I decided to make such a soil by mixing charcoal particles with soil. We made this soil by mixing normal clayey soil (mostly subsoil) with charcoal and coconut fibre in equal proportions by volume. The charcoal was conventional charcoal produced by the kilning of mangrove wood. This came in large hard pieces that had to be broken up mechanically. The resulting particles were irregular in size and difficult to mix with the clay and fibre. I then found a much better source of charcoal in the factory of a charcoal briquette manufacturer. Charcoal briquettes are made by compressing sawdust into standard-size briquettes for kilning. The briquettes, meant for the barbecue market, can be easily broken into particles, sieved to remove dust and graded into the desired sizes. We refer to the product as horticultural carbon (Ng, 2006). We use two sizes: 1 – 4 mm particles for potting mixtures and 5 – 12 mm for garden beds.

We have found that a mixture of equal parts horticultural carbon and clay soil is good for general purpose horticulture. A mixture of three parts carbon to one part soil is better for cacti and succulents that need exceptionally well-drained soil.

Horticultural carbon is half the weight of soil, so the mixtures we make are lighter and more porous than ordinary garden soil. The reduction in weight was an important factor in my next project, a garden on the roof of the same shopping mall, seven floors above the ground. This garden, known as the Secret Garden of 1 Utama is now open to the public at weekends.

The porosity of soil mixed with horticultural carbon greatly reduces the labour of weeding because the weeds can be pulled out easily. However horticultural carbon only holds half the amount of water that an equivalent mass of clay soil will hold. Its lower water-holding capacity, together with its porosity, means that horticultural carbon dries out much faster than clay soils. The drying of the soil medium can be very damaging to the roots of plants, hence we find it necessary to keep our medium kept moist all the time. This can be arranged in various ways, for example, by watering twice a day. In pots, we would recommend placing the pots on shallow trays to hold water.

Horticultural carbon does not contain nutrients, hence fertilizers have to be applied regularly.

Initially the carbon and clay particles remain separate though mixed. Gradually the carbon wears down and becomes integrated with the clay, with consequent settling of the soil mixture. The soil level drops and is topped up with pure carbon.

The performance of plants on horticultural carbon
Our most extreme experiment was to grow rice on 100% horticultural carbon in plastic basins. The basins, about 20 cm deep, were three-quarters filled with carbon particles and topped up with water. Rice seeds were sown direct on the surface. Our Indonesian workers, rice-growers in their former lives, all had a good laugh because “everybody knows that rice only grows on tanah liat (sticky clay soil)”. Well, our rice grew and produced a heavy crop of grains. We have now grown three successive crops. The roots form very dense mats. After each crop, the roots have to be dried out before the carbon particles can be shaken out and recovered..

For cacti and succulents, we use a mix of 75% carbon to 25% burnt soil in elevated beds. Some species thrive, but some still find it too wet, and rot when it rains daily. Nevertheless ours is the only decent-looking cactus bed exposed to tropical rain in Kuala Lumpur.

Begonias, calatheas, and aglaonemas grow well in 50:50 mixes on raised beds provided 50 - 75% of the sunlight is cut off using shade-nets.

Of temperate plants and montane plants, we have managed to grow apple, peach, plum, Magnolia grandiflora, Magnolia liliiflora, arabica coffee, azalea, camellia, day lilies and Platanus. It has been hypothesized that in the tropics, the high night-time temperatures raise the night-time respiration rate to a level that temperate plants cannot adapt to. We think a high carbon mix allows air (oxygen) to get to the roots more easily, making it easier for temperate plants to adapt. However the flowering patterns of temperate plants are disrupted by the lack of seasons. Some species do not flower at all (e.g. day lilies), some flower infrequently and sparingly (e.g. apple and plum), and some flower all through the year (e.g. Magnolia liliiflora and arabica coffee).

Where to see horticultural carbon in use
In Malaysia, the Secret Garden of 1 Utama in Petaling Jaya, occupying 0.25 ha of flat roof top 7 floors above the ground, is the largest display open to public view. Here are grown over 500 species of plants, including palms, orchids, temperate plants, flowers, spices, rice, cacti, climbers and grasses. Also in 1 Utama but on the lower ground floor, is a rainforest with some 50 species of timber trees growing on a horticultural carbon mixture. In Sarawak, the Laila Taib Ethno Garden of the Sarawak Biodiversity Centre at Semengok, Kuching, displays a good range of native herbs grown on horticultural carbon, most of them larger and healthier than in their original rain forest habitats.

Horticultural carbon in carbon sequestration
Since the Industrial Revolution, the amount of carbon dioxide in the atmosphere has increased significantly, to bring about global warming. The increase in carbon dioxide in the atmosphere is due partly to the extraction and burning of coal and petroleum and partly to the clearing of forests, which reduces the amount of organic carbon stored in forests.

Proposed measures to control global warming include reduction in consumption of coal and petroleum and the planting of trees and forest to convert atmospheric carbon dioxide into organic carbon. However, reduction in consumption has proven to be difficult, and trees and forests fix carbon efficiently only when they are in active growth, i.e. during their juvenile phase. When trees die, organic carbon is converted back to carbon dioxide through the normal processes of decay.

The conversion of wood to charcoal fixes carbon more permanently and the use of such carbon as a horticultural medium kills two birds with one stone. Horticultural carbon acts as a carbon store but instead of being just a passive store, its use as a high performance horticultural medium helps to solve the other global problem, of increasing food production in the world. On our roof top garden the average use of horticultural carbon is 1 tonne (equivalent to a volume of 2 m3 ) to cover 6m2 of floor area. Our manufacturer of horticultural carbon is yoltan@tm.net.my

References
Holttum, R.E. 1053. Gardening in the Lowlands of Malaya. Staits Times Press, Singapore.
Ng, F.S.P. 2006. Tropical Horticulture and Gardening. Clearwater Publications, Kuala Lumpur.

Thursday, April 30, 2009

Tropical rooftop garden reviewed

The Secret Garden of One Utama, situated on the roof of a seven-floor shopping mall in Kuala Lumpur and occupying one quarter of a hectare, has received rave reviews in the Malaysian press. It got one full page in the Star, one full page in Sin Chew News, and a half page in Guang Ming News. The New Straits Times feature will appear shortly and a video will also be made available in the New Straits Times website.

We found that different visitors had different interests, so our strategy of providing a variety of themes turned out to be correct. The themes are (1)temperate plants (2)desert plant (3)tropical climbers (4)food plants (5)flowers (6)colourful foliage and (7)iconic plants.

The garden is different from Eden in Cornwall in that it is not covered. The whole garden is exposed to tropical temperature and rain.

With this experience and our experience in growing a tropical rain forest within a shopping mall, we are now ready to design a roofed structure that will house an integrated combination of forest, garden, shopping and dining. The vegetation can be fully tropical but the temperature and light can be maintained at more comfortable levels.

Saturday, April 25, 2009

High-tech tropical garden in Malaysia now open to public

The Secret Garden of One Utama was opened to the public today at a special launching ceremony by Dato C.K. Teo. This garden is on the rooftop of the 'One Utama' shopping mall in Petaling Jaya and is the largest rooftop garden in SE Asia. It uses novel technologies like granulated carbon as the soil medium and a chilled water delivery system at night. Over 500 species are grown here including many that one would not expect to see in the tropical lowlands, like apple, plum, magnolia and arabica coffee. Also cacti, olives and other dry climate plants. Also staples like rice and sorghum, and spices like pepper, ginger, clove and nutmeg. And lots of flowers in bloom. The garden took over three years to develop. Situated on top of a 7 floor building, its development has been a well-kept secret.

Entrance is free. The garden is open on Saturdays and Sundays at 10 am to 6 pm. Visitors have to obtain a free pass from the reception counter. Only 100 passes are issued per hour.

The press was present in force at the launching and I have never seen reporters and press photographers in such a state of excitement. The Patron and the President of the Selangor Gardening Society and senior members of the landscape profession were amazed by what they saw. I have to stop here so as not to give any more secrets away.

Sunday, March 15, 2009

Gobal recession affects garbage disposal

The old newpapers in my house have been piling up during the past few weeks. Then it hit me that the people who come around collecting old newspapers have stopped making their rounds. This must be because the recycling factories have been hit by the recession.

At the peak of the economic bubble last year, thieves went on a rampage, stealing metal signboards, manhole covers and electric cables. When the bubble burst, the thievery stopped, and that was a good thing. Now, the recession is likely to become environmentally ominous, with old newsprint, plastic, glass and other recyclable things uncollected and filling up the dumpsites.

Governments have announced plans to boost the economy. Most of the money will go to the glamour industries. How about supporting the recyclers and garbage collectors to stay in business? They are perhaps as important as banks and motocar manufacturers.

Friday, February 20, 2009

David Fairchild and the UN Convention on Biodiversity

Earlier this month I traveled to Miami to receive the David Fairchild Medal for plant exploration. On the long trip, I had time to think about the legacy of David Fairchild and other plant explorers.

Plant explorers have been responsible for the internationalization of many of the plants that we use for food, flowers, medicines and other natural products. Just think what life would be like if, in the year 1492, international law had made it impossible to take plants from one place to another without first agreeing with local authorities to pay royalties in perpetuity for plants taken out of their lands. Perhaps eighty percent of all the food that city people eat, and most of the plants that farmers and gardeners grow, would be deleted, for such is our dependence worldwide on the sharing of plant genetic resources. Almost nobody is free from such dependence. There would be total legal gridlock over who to pay, how much, and to whom.

Before the UN Convention on Biodiversity, genetic resources were considered the common resource of humankind. This principle was rejected at the Convention, and biodiversity became the property of nations. In Malaysia, the nation is a federation of component states, so the individual states have laid claim to ‘their biodiversity’. Within the state of Sarawak, the tribal communities of the interior now have the idea that they own the germplasm on their tribal lands. Within the tribal communities, adjacent villages are now concerned about which plants in the forest belong to which community.

All this began with US Court decisions allowing the patenting (in effect, grants of ownership) of biological materials. Since then, we have been sliding down a slippery slope. In the US, they say patents are necessary to promote investment in research and development. In the developing countries, they think money will be made in royalties or rents from the sale of rights to access their biodiversity.

Before boarding my flight to the US I bought a copy of Newsweek. In it was an article on how the development of new medicines has been stymied by the dense thicket of patents in the way. The big pharmaceutical companies have found it impossible to negotiate though such thickets. Goodbye to major advances in drug discovery!

This reminded me of a conference in Kuching that I attended recently, at which a representative of Bioversity (the international organization that promotes the conservation of agricultural biodiversity), said that international plant breeding work has come almost to a standstill. Plant breeding requires the use of breeding stocks of diverse origins, and nobody wants the hassle of negotiating with multiple claimants for the right to use breeding materials. The Green Revolution of the 1950s to 1980s, based on high-yielding cereals and other food crops bred from germplasm made freely available to plant breeders, has kept the world free of famine since World War II. This era of plant-breeding in the service of humanity has ended. Nobody in their right minds would want to get entangled in a legal gridlock. There will not be another green revolution!

I was carrying with me a scientific presentation to deliver in conjunction with the Award. In that presentation, I had to cite from the work many other scientists—very few scientific papers can be written without reference to previous works. If it had been obligatory to obtain permission from each of the scientists I had to cite, I would never have written my paper. But science is based on the principle that knowledge is the universal property of all humankind as soon as it is published. Those who do not share, do not publish, do not get cited, and do not get recognized. If all scientists withdraw from sharing of knowledge, it would be goodbye to science!

But universities and research institutions have been diverting money from research into patent application, counting their patents as a measure of research productivity. Patent offices, swamped by patent applications, are approving patents with lower and lower standards of examination. They have decided leave it to the patent holders to sort themselves out in court. Eventually, nobody will be able to afford the legal costs, not even the commercial organizations that lobbied for patent protection in the first place.