During the spring of 1998 a case study was executed in the natural forests of the Himalayan Mountains in Bhutan. The Third Forestry Development Project in Eastern Bhutan was selected to demonstrate that environmentally sensitive forest engineering can significantly reduce the damaging effects of forest road construction. The study, by Norbert Winkler, documents each phase of road construction, both by excavator and by bulldozer and compares the impacts. Data were collected on both construction techniques under similar site conditions.
Observed Construction Production Rates | ||
Construction type |
Metres per hour of workplace time | |
Bulldozer construction |
13.6 | |
Excavator construction |
5.6 | |
These production rates refer to the establishment of the road cross section excluding the hillside ditch. | ||
Data were also gathered on a long-distance cable crane yarding system operated both in a traditional and a modified, more environmentally sensitive group selection clear-felling operation.
Observed Yarding Production Rates | ||
does not look good (empty |
Cubic metres per workplace hour | |
Traditional clear-felling |
3.9 | |
Group selection felling |
5.0 | |
These production rates were observed for the extraction of logs by long-distance cable crane | ||
Excavator built road in Bhutan Bhutan cable-crane harvesting
The results of this case study show that environmentally friendly excavator road construction as applied in the Kharungla road project is superior, from an environmental point of view, to road construction in the traditional way by bulldozers as applied in the Korila project. The short-term economic benefits from use of bulldozers in forest road construction in mountainous terrain are likely in the longer run to create environmental damage on a substantial scale.
The observed potential for improvement should encourage introduction of advanced techniques throughout Bhutan.
The long distance cable-crane solution makes use of the available skills and equipment in the country, contributes to the livelihood of the local people and improves the overall development in rural areas.
For the complete report see FAO Forest Harvesting Case Study 12, Environmentally Sound Forest Infrastructure Development And Harvesting By Long Distance Cable Systems In The Himalayan Region of Bhutan, 1999.
Several reference sources are available in both published and electronic form. The dictionary of forestry, produced jointly by CAB International, and Society of American Foresters was published this year. An interesting four language glossary was published by the Italian National Institute of Research. Glossario multilingue dei termini usati in tecnologia del legno, CNR/IRL, Florence, Italy. Term definitions are in Italian and the cross-referenced terms are sorted alphabetically in English, French and German. See page eight for complete citations.
In this age of internet access there are several good on-line glossaries. Two English language glossaries are:
The compilation of general terms used in reports by the Ministry of Forests, British Columbia, Canada. The entire glossary is available for downloading as a self-extracting zip file from the web site in Canada. The address is: www.for.gov.bc.ca/pab/publctns/glossary/glossary.htm
Timber Glossary, by Bryce Stokes, Colin Ashmore, Cynthia Rawlins, and Donald Sirois. A glossary of terms used in timber harvesting and forest engineering. Gen. Tech. Rep. S0-73. New Orleans, LA: USDA Forest Service. Available online by the Renewable Resource Data Center at http://rredc.nrel.gov/biomass/forest/tim_glossary/
