N.Z. tips for Bhutan forestry

Press, 17 December 1988, Page 22

N.Z. tips for Bhutan forestry

New Zealand forestry scientists have a lot to teach the Bhutanese — and in return there is much that we can learn from Bhutan’s experiences, according to a Christchurch scientist who recently visited this mountainous country in the northern highlands of the Indian subcontinent.

Mr Alan Nordmeyer, of the Forest Research Centre at Ham, went to Bhutan as part of a scientific exchange between the two countries. He described some of his experiences and impressions of the country last week, at a seminar at Ham. Mr Nordmeyer and his colleagues are advising Bhutan on several aspects of forestry and pasture improvement. The Ministry of Forestry is cooperating on agroforestry developments and advising on revegetation, using expertise developed largely through its long-term research projects at Craigieburn, in central Canterbury. Several pasture plants familiar in New Zealand — including white clover, Maku lotus, and Italian ryegrass — have been introduced in Bhutan, and white clover is thriving there at altitudes up to 3500 metres.

Bhutan is a small mountainous country which, like New Zealand, has a range of climates from rainforest to Canterburytype vegetations, in the drier areas behind the rain shadow of the high Himalayas. In the latter region, says Mr Nordmeyer, there is a prospect of growing seed crops, particularly legumes. “Lotus,” he said, “has huge potential.” At present the major

grain crop in Bhutan is buckwheat, a member of the dock family which is little known in New Zealand. Most farms in Bhutan are very small — about one hectare on average. But they are intensively cropped, and agriculture continues right up above the tree line, to the limits of vegetation, with people ekeing out a living where they can, according to Mr Nordmeyer. Originally the country, 350 km across, was forested to high altitudes, but most of the original forests have been cut over for timber, firewood, or animal fodder or to clear space for crops and, as in New Zealand,

there have been major changes in the nature and composition of the dominant vegetation in the last 150 years. The construction of several major hydro-electricity schemes since the 1960 s has taken much of the pressure off the firewood supply, and as a consequence there are many stands of trees about 15 years old. But these “new forests” differ in their composition and in the dominant species from the old forests. At higher altitudes and in the colder and drier region the blue pine, Pinus wallichiana, is a particularly aggressive coloniser and is invading many areas where it was not dominant originally. On the warmer hills at lower altitudes, another conifer, the Chir pine, Pinus roxburghii, is becoming dominant over large areas. These “indigenous invaders” are changing the face of Bhutan. Bhutan, says Mr Nordmeyer, is a colourful country; most buildings are gaily decorated with bright colours and people wear brightly coloured garments, woven in traditional patterns. Weaving is a major cottage industry. By and large, the country has a cottage-industry economy, based on the intensive cultivation of small blocks of land.

A mountainous country, Bhutan consists of a series of successively higher ranges, rising to the “Roof of the World,” and separated by deep valleys, through which flow substantial rivers flanked by tropical forest. There is virtually no flat ground. Large parts of the country are, according to Mr Nordmeyer, not unlike North Island hill country and the likeness is accentuated by similarities in vegetation — mixed conifer-broadleafed forests, open areas of scrub containing species of coriaria very similar to those of New Zealand (where they are known as “tutu”), and species of sophora similar to their relatives in New Zealand, the kowhai. Forestry is a major industry and New Zealand is committed to a programme of development and assistance. Major agroforestry developments are under way, and there is a chance also for New Zealand to assist the Bhutanese in grappling with a problem similar to one occurring in New Zealand’s high-altitude protection forests: canopy dieback. In New Zealand it is the rata, a broadleafed species, that is dying. In Bhutan an important conifer is being lost — the tall fir that dominates huge areas of forest. Bhutan’s fir forests, says Mr

Nordmeyer, are suffering massive and widespread dieback. A big replanting and revegetation programmes is under way and a network of tree nurseries has been established at high altitudes. Thanks to the research done at Craigieburn and other sites over the last quarter-century, New Zealand has a huge resource of knowledge about the revegetation of depleted and eroded mountain areas. Thanks to the long-term studies of rata-kamahi dieback, it also has good information about the problems of dying forests. The opportunity exists for that knowledge to be put to practical use in the regreening of Bhutan. On that question of expertise: New Zealand’s forest industry is largely based on a single species, radiata pine, and this country has probably more expertise than any other in the growing of radiata — expertise gathered over a long time from both practical experience and intensive research into all aspects of pine forestry, from harvesting the seed to cutting up the tree and treating the timber. Are we right to devote so much attention to one species, almost to the exclusion of everything else? Radiata pine now comprises about 90 per cent of

New Zealand’s exotic forest resource.

Many foresters are not at all happy about this situation and farm foresters are particularly unhappy about it. They are likely, when they hold their annual conference in Gisborne next March, to press strongly for diversification. Members of the Central Canterbury branch of the Farm Forestry Association have already launched a campaign for a big boost in research into “alternative” timber species, and at their annual meeting this month they instructed their committee to prepare a remit on the subject. An alternative species, in forestry terms, is just about any tree other than radiata pine or Douglas fir. The term embraces evergreen and deciduous broadleafed trees (“hardwoods” in forestry parlance), as well as some of the lesser known softwoods (conifers) such as cypresses. Much of New Zealand’s limited resource of this type of timber are to be found in small, private woodlots, and, as was pointed out in an article in the last issue of the association’s journal, “Tree Grower,” there is a looming world shortage of hardwood timber but no likelihood in the

foreseeable future of a softwood shortage.

The association has begun a survey of its own members in an attempt to quantify this resource, and has also set up, in conjunction with the Forest Research Centre, d “Macrocarpa Action Group” to investigate the possible development of cypress timber trees.

The group has already planted trial areas with different provenances of macrocarpa, raised from seeds and cuttings. Some effort has been made to identify good seed trees that will throw progeny with good form and growth rates, and quite a lot has already been learned about the management of macrocarpa for timber production.

However, much more needs to be known about potential growth rates and-timber qualities of the whole cypress family, several species in which yield timber of excellent quality. Macrocarpa itself is highly regarded for boatbuilding and joinery and is durable in outside construction work, so long as it is not in contact with the ground. Leyland cypress timber is of comparable quality. Close attention to breeding, selection, and management may

well enable the cypresses of the future to compete successfully with pines — provided the research continues and expands. Under the present regime the amount of Government funding for this type of long-term research is limited, and the association’s own resources are also limited. So a sponsor is being sought to expand the cypress research — or maybe just to enable it to continue. If you think you can help, get in touch.

Gisborne, the venue of the conference at which these matters will be discussed, was chosen five years ago but has proved to be a very timely selection, after the devastation of the east coast by Cyclone Bola. The theme of the conference will be “Planting plus protection equals production plus prosperity.”

The programme includes visits to Mangatu, a 7000 ha soilconservation forest planted since the 1960 s to major agroforestry developments, to a long-estab-lished family farm where woodlots were planted before World War I, and to arboreta, including the famous Eastwoodhill, perhaps the nearest thing New Zealand has to a national arboretum.

“The sun,” someone said to me the other day, "must be mighty hot in your part of Canterbury if it bleaches the macrocarpas.” Not at all, I told him. Just gremlins at work on last week’s column. Bleached macrocarpas indeed! What I wrote was “pleached macrocarpas.”