Skip Navigation

Forestry 2003 76(5):491-507; doi:10.1093/forestry/76.5.491
© 2003 by Institute of Chartered Foresters
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Fontes, L.
Right arrow Articles by Savill, P.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Modelling the Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) site index from site factors in Portugal

Luis Fontes1, Margarida Tomé2, Frank Thompson1, Alistair Yeomans1, Jaime Sales Luis3 and Peter Savill1

1 Oxford Forestry Institute, University of Oxford, South Parks Road, Oxford OX1 3RB, England 2 Instituto Superior de Agronomia, Universidade Técnica de Lisboa, Tapada da Ajuda, 1399 Lisboa Codex, Portugal 3 Secção Florestal, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, Apartado 1013-5000-911, Vila Real Codex, Portugal

Although the speed of growth and adaptability of the north-west American conifer Douglas-fir has been recognized in Portugal, it represents only ~0.1 per cent of the total forest cover. This small area is spread across the mountainous areas of the north and centre of the country. This study models Douglas-fir productivity based on site factors and estimates the potential area for Douglas-fir in Portugal. Soil, climate and topographic data were collected on 39 plots across the range of sites where Douglas-fir grows in Portugal. The analysis of the data followed three steps: (1) selection of site factors related to the variation in the site index; (2) choice of candidate models; and (3) consideration of the best model to explain and predict the site index from site factor variables. The best multiple linear regression model explained 90 per cent of site index variation but included variables not readily available in the field. A model using digitized site data explained 54 per cent of the variation in the site index and mapped the areas with potential for Douglas-fir growth in Portugal. It is estimated that a potential Douglas-fir planting area of 250 000 ha exists where trees will exceed 17 m dominant height at age 30 years. This would correspond to 8 per cent of the existing Portuguese forest area. The best sites for Douglas-fir growth are located along north coastal to central regions at altitudes between 500 m and 1000 m with moisture deficit (precipitation minus evapotranspiration) above 1000 mm. Areas with acceptable sites for Douglas-fir growth are located in the north and centre of Portugal at 700–1000 m elevation and have a moisture deficit above 400 mm.

Received 5 February 2003.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.