Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah.
Growth models can contribute to the forest management decision making process by providing stand development forecasts. Mahogany plantation in Gum-Gum Forest Reserve Sabah was planted in 1968 with spacing 2.74×2.74 m within an area of 0.52 hectare. Diameter at breast height (dbh) and tree height dat...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English English |
| Published: |
2009
|
| Online Access: | http://psasir.upm.edu.my/id/eprint/15671/ http://psasir.upm.edu.my/id/eprint/15671/1/Modelling%20growth%20of%20swietenia%20macrophylla.pdf |
| _version_ | 1848842743120396288 |
|---|---|
| author | Ng, Y. M. Abd Kudus, Kamziah Chia, F. R. Lapongan, Jaffirin Pang, K. N. K. |
| author_facet | Ng, Y. M. Abd Kudus, Kamziah Chia, F. R. Lapongan, Jaffirin Pang, K. N. K. |
| author_sort | Ng, Y. M. |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Growth models can contribute to the forest management decision making process by providing stand development forecasts. Mahogany plantation in Gum-Gum Forest Reserve Sabah was planted in 1968 with spacing 2.74×2.74 m within an area of 0.52 hectare. Diameter at breast height (dbh) and tree height data were collected from year 1969 to 2006. This study aimed to determine the efficient regression equations for growth prediction of the mahogany plantation. Regression models were developed by search from literature as a basis references. Four diameter prediction models and six height prediction models were developed. Proc Reg in SAS was used to evaluate the regression equations. Performance of the model was measured by using root mean square error (RMSE), bias and coefficient of determination (R2). The chosen diameter prediction model is lnH=3.07-10.42D-1+0.1lnA with RMSE (0.31), bias (1.76) and R2 (0.68). The recommended prediction model slightly underestimated the actual diameter. The chosen height prediction model is lnD=354-3.98A-1 with RMSE (0.11), bias (0.01) and R2 (0.91). This recommended height prediction model gives very close height estimate to the actual height. |
| first_indexed | 2025-11-15T08:03:59Z |
| format | Article |
| id | upm-15671 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English English |
| last_indexed | 2025-11-15T08:03:59Z |
| publishDate | 2009 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-156712015-12-18T07:36:07Z http://psasir.upm.edu.my/id/eprint/15671/ Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. Ng, Y. M. Abd Kudus, Kamziah Chia, F. R. Lapongan, Jaffirin Pang, K. N. K. Growth models can contribute to the forest management decision making process by providing stand development forecasts. Mahogany plantation in Gum-Gum Forest Reserve Sabah was planted in 1968 with spacing 2.74×2.74 m within an area of 0.52 hectare. Diameter at breast height (dbh) and tree height data were collected from year 1969 to 2006. This study aimed to determine the efficient regression equations for growth prediction of the mahogany plantation. Regression models were developed by search from literature as a basis references. Four diameter prediction models and six height prediction models were developed. Proc Reg in SAS was used to evaluate the regression equations. Performance of the model was measured by using root mean square error (RMSE), bias and coefficient of determination (R2). The chosen diameter prediction model is lnH=3.07-10.42D-1+0.1lnA with RMSE (0.31), bias (1.76) and R2 (0.68). The recommended prediction model slightly underestimated the actual diameter. The chosen height prediction model is lnD=354-3.98A-1 with RMSE (0.11), bias (0.01) and R2 (0.91). This recommended height prediction model gives very close height estimate to the actual height. 2009 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/15671/1/Modelling%20growth%20of%20swietenia%20macrophylla.pdf Ng, Y. M. and Abd Kudus, Kamziah and Chia, F. R. and Lapongan, Jaffirin and Pang, K. N. K. (2009) Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. The Malaysian Forester, 72 (2). pp. 209-218. ISSN 0302-2935 http://www.cabi.org/cabdirect/FullTextPDF/2010/20103067508.pdf English |
| spellingShingle | Ng, Y. M. Abd Kudus, Kamziah Chia, F. R. Lapongan, Jaffirin Pang, K. N. K. Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. |
| title | Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. |
| title_full | Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. |
| title_fullStr | Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. |
| title_full_unstemmed | Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. |
| title_short | Modelling growth of swietenia macrophylla (mahogany) plantation in Gum-Gum Forest Reserve, Sabah. |
| title_sort | modelling growth of swietenia macrophylla (mahogany) plantation in gum-gum forest reserve, sabah. |
| url | http://psasir.upm.edu.my/id/eprint/15671/ http://psasir.upm.edu.my/id/eprint/15671/ http://psasir.upm.edu.my/id/eprint/15671/1/Modelling%20growth%20of%20swietenia%20macrophylla.pdf |