Height-Diameter Allometry for Tree Species in Tanzania Mainland
Total tree height (H) and diameter at beast height (D) are important independent variables in predicting volume, biomass, and other forest stand attributes. However, unlike D measurement, which is easy to measure with high accuracy, H measurement is laborious. This study, therefore, developed H-D re...
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| Format: | Article |
| Language: | English |
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Wiley
2019-01-01
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| Series: | International Journal of Forestry Research |
| Online Access: | http://dx.doi.org/10.1155/2019/4832849 |
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| author | W. A. Mugasha E. W. Mauya A. M. Njana K. Karlsson R. E. Malimbwi S. Ernest |
| author_facet | W. A. Mugasha E. W. Mauya A. M. Njana K. Karlsson R. E. Malimbwi S. Ernest |
| author_sort | W. A. Mugasha |
| collection | DOAJ |
| description | Total tree height (H) and diameter at beast height (D) are important independent variables in predicting volume, biomass, and other forest stand attributes. However, unlike D measurement, which is easy to measure with high accuracy, H measurement is laborious. This study, therefore, developed H-D relationships for ten different forest types in Tanzania Mainland. Extents in which climate and forest stand variables explain the variation in H-D allometry were also assessed. A total of 31782 sample trees covering miombo woodlands, humid montane, lowland forests, bushlands, grasslands, mangroves, cultivated land, wetlands forests, and pines and Eucalyptus species plantations were used for model development. The H estimating model without climate and forest stand variables referred herein as “base model” was first developed followed by “generalized model” which included climate and stand variables. All the data were fitted using nonlinear mixed effect modelling approach. Results indicated that generalized H estimating models had better fit than the base models. We therefore confirm a significant contribution of climate and forest structure variables in improving H-D allometry. Among the forest structure variables, basal area (BA) was far more important explanatory variable than other variables. In addition, it was found that the mean tree H tends to increase with the increase of mean precipitation (PRA). We therefore conclude that forest specific generalized H model is to be applied when predicting H. When forest type information is not available, generalized regional model may be applied. Base model may be applied when forest stand or climate information are missing. |
| format | Article |
| id | doaj-art-265d916ba3814a12a7fdcf6204ef7ea3 |
| institution | OA Journals |
| issn | 1687-9368 1687-9376 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
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| series | International Journal of Forestry Research |
| spelling | doaj-art-265d916ba3814a12a7fdcf6204ef7ea32025-08-20T02:04:26ZengWileyInternational Journal of Forestry Research1687-93681687-93762019-01-01201910.1155/2019/48328494832849Height-Diameter Allometry for Tree Species in Tanzania MainlandW. A. Mugasha0E. W. Mauya1A. M. Njana2K. Karlsson3R. E. Malimbwi4S. Ernest5Department of Forest Resources Assessment and Management, College of Forestry, Wildlife and Tourism, Sokoine University of Agriculture, Box 3013, Morogoro, TanzaniaDepartment of Forest Engineering and Wood Sciences, College of Forestry, Wildlife and Tourism, Sokoine University of Agriculture, Box 3012, Morogoro, TanzaniaNational Carbon Monitoring Centre, Box 3013, Morogoro, TanzaniaNatural Resource Institute of Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, FinlandDepartment of Forest Resources Assessment and Management, College of Forestry, Wildlife and Tourism, Sokoine University of Agriculture, Box 3013, Morogoro, TanzaniaTanzania Forest Research Institute, Box 1854, Morogoro, TanzaniaTotal tree height (H) and diameter at beast height (D) are important independent variables in predicting volume, biomass, and other forest stand attributes. However, unlike D measurement, which is easy to measure with high accuracy, H measurement is laborious. This study, therefore, developed H-D relationships for ten different forest types in Tanzania Mainland. Extents in which climate and forest stand variables explain the variation in H-D allometry were also assessed. A total of 31782 sample trees covering miombo woodlands, humid montane, lowland forests, bushlands, grasslands, mangroves, cultivated land, wetlands forests, and pines and Eucalyptus species plantations were used for model development. The H estimating model without climate and forest stand variables referred herein as “base model” was first developed followed by “generalized model” which included climate and stand variables. All the data were fitted using nonlinear mixed effect modelling approach. Results indicated that generalized H estimating models had better fit than the base models. We therefore confirm a significant contribution of climate and forest structure variables in improving H-D allometry. Among the forest structure variables, basal area (BA) was far more important explanatory variable than other variables. In addition, it was found that the mean tree H tends to increase with the increase of mean precipitation (PRA). We therefore conclude that forest specific generalized H model is to be applied when predicting H. When forest type information is not available, generalized regional model may be applied. Base model may be applied when forest stand or climate information are missing.http://dx.doi.org/10.1155/2019/4832849 |
| spellingShingle | W. A. Mugasha E. W. Mauya A. M. Njana K. Karlsson R. E. Malimbwi S. Ernest Height-Diameter Allometry for Tree Species in Tanzania Mainland International Journal of Forestry Research |
| title | Height-Diameter Allometry for Tree Species in Tanzania Mainland |
| title_full | Height-Diameter Allometry for Tree Species in Tanzania Mainland |
| title_fullStr | Height-Diameter Allometry for Tree Species in Tanzania Mainland |
| title_full_unstemmed | Height-Diameter Allometry for Tree Species in Tanzania Mainland |
| title_short | Height-Diameter Allometry for Tree Species in Tanzania Mainland |
| title_sort | height diameter allometry for tree species in tanzania mainland |
| url | http://dx.doi.org/10.1155/2019/4832849 |
| work_keys_str_mv | AT wamugasha heightdiameterallometryfortreespeciesintanzaniamainland AT ewmauya heightdiameterallometryfortreespeciesintanzaniamainland AT amnjana heightdiameterallometryfortreespeciesintanzaniamainland AT kkarlsson heightdiameterallometryfortreespeciesintanzaniamainland AT remalimbwi heightdiameterallometryfortreespeciesintanzaniamainland AT sernest heightdiameterallometryfortreespeciesintanzaniamainland |