TRAVEL / How to be an eco-tourist: Martin Wright on organisations that ensure your holiday does more good than harm

'ECO-TOURISM' is a somewhat overused term, covering anything from a weekend dry-stone walling in the Yorkshire Dales to six months roughing it in a truck through the heart of Africa.

The working holiday has to be the most eco-friendly, through such organisations as Earthwatch, where the holidaymakers help out on a range of practical environmental projects. This is one of the fastest growing areas of 'green' tourism, not least because it offers the chance to show off a virtuous halo and a lean, healthy look along with the tan. The better ones back up the work with training in basic conservation skills.

You don't have to don your jungle boots to take part. The British Trust for Conservation Volunteers (0491 39766) is the largest organisation of its kind in the country, with extensive experience of matching the enthusiastic amateur to the job worth doing. It offers a range of 'Natural Break' holidays in Britain and Europe, restoring degraded landscapes and teaching traditional skills such as hedge-laying and coppice-making. The Royal Society for the Protection of Birds (0767 680551) gives enthusiastic twitchers the chance to act as volunteer wardens on its reserves: you could find yourself surveying seabirds or helping mount a 24-hour guard on an osprey's nest. Alternatives include the Acorn Projects run by the National Trust (071-222 9251). At pounds 25- pounds 30 a week including food, such breaks must be among the cheapest holidays on offer, but those seeking a lie-in should be warned that eight-hour days are common.

A more personal touch, perhaps, is available via Working Weekends on Organic Farms (0273 476286), which links hard-pressed growers with frustrated urban fans of the Good Life who are willing to get their hands dirty in return for bed and board. Again, some serious toil is expected.

Further afield, an easier ride is guaranteed by the Sunseed Trust (0223 462244), which asks for just four hours' work a day on its desert reclamation research project in southern Spain, at a cost of pounds 50 per week.

For the more adventurous, there's Trekforce Expeditions (071-498 0855), which packs volunteers off for six weeks' field work in the rainforests of Indonesia, supporting three projects run by the International Scientific Support Trust. No experience is necessary, but a willingness to 'rough it' is essential. 'Trekkers' are mostly young, many of them students. The organisation's publicity sums up the appeal of this type of holiday, claiming that 'others offer exploration holidays, but Trekforce gives you the satisfaction of travelling for a worthwhile purpose as well as for adventure'. It also provides the sort of jungle training you'd otherwise have to join the Marines for. Others in the same vein include World Challenge Expeditions (081-964 1331) and the Survival Club (0931 714444) which, among other activities, stages clean-ups of the world's highest rubbish tip - Base Camp on Everest.

If you don't fancy getting your own hands dirty, you could do worse than see the beneficial impact of those who do. A growing number of tours combine holidays with visits to projects run by major charities. Discover the World (0737 373789) has joined up with the World Wide Fund for Nature to take tourists round WWF projects, in the company of its field workers. Prices, which include a contribution to WWF, range from pounds 250 for a weekend among the wild flowers of Ireland's Burren, to pounds 2,140 for a panda- tracking expedition through the bamboo forests of China. Ecotrails (081-846 9963) operates on the same principle with Oxfam projects in India. One World Tours (081-946 6295) has the added ingredient of home stays with local families as a background to round off visits to development projects in Asia, Africa, and Latin America (prices from pounds 700 for two weeks). Insight Travel (0995 606095) arranges stays with Ashanti villagers in Ghana.

For those in search of a more conventional holiday, there are a number of companies which go out of their way to support local environmental initiatives. In Britain, Countrywide Holidays (061-225 1000) specialises in walking holidays, particularly in the Lake District, with a proportion of proceeds going to local conservation work. Abroad, two of the most established operators are Cox & Kings (071-931 9106) and Abercrombie & Kent (071-730 9600). The former, established in 1758, offers encounters with the 'Gorillas in the Mist' in the mountains of Rwanda, as well as tours in the rainforests of Zaire and the Amazon; A & K specialises in East African safaris, bringing an all-too-rare level of environmental responsibility to an area which has suffered heavily from uncontrolled tourism.

Both companies give practical and financial support to local environmental programmes. Similar commitments are made by Grassroots Travel (081-941 5753), with a range of African holidays, and Worldwide Journeys and Expeditions (071-370 5032), which even runs its own wildlife park in Zambia. Holidays such as these don't come cheap - many cost more than pounds 2,000 - but they do offer some peace of mind to tourists concerned lest their holiday should contribute to the destruction of the very environment they have come to see.

An excellent survey of 'eco-tourism' options and the issues involved can be found in The Good Tourist by Katie Wood (Mandarin Books pounds 5.99). The main campaigning organisation on these issues is Tourism Concern (081-878 9053).-

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