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Height-diameter allometry for tree species in Tanzania mainland / Wilson Ancelm Mugasha in International journal of forestry research, vol 2019 ([01/03/2019])  

Public [article]  inInternational journal of forestry research > vol 2019 [01/03/2019] Titre : Height-diameter allometry for tree species in Tanzania mainland Type de document : Article/Communication Auteurs : Wilson Ancelm Mugasha, Auteur ; E.W. Mauya, Auteur ; et al., Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] allométrie [Termes IGN] diamètre des arbres [Termes IGN] Eucalyptus (genre) [Termes IGN] hauteur des arbres [Termes IGN] inventaire forestier étranger (données) [Termes IGN] modèle mathématique [Termes IGN] Pinus (genre) [Termes IGN] Tanzanie [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) 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. Numéro de notice : A2019-371 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1155/2019/4832849 Date de publication en ligne : 21/04/2019 En ligne : https://doi.org/10.1155/2019/4832849 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93397 [article]

Allometric models for estimating tree volume and aboveground biomass in lowland forests of Tanzania / Wilson Ancelm Mugasha in International journal of forestry research, vol 2016 ([01/08/2016])  

Public [article]  inInternational journal of forestry research > vol 2016 [01/08/2016] . - 13 p. Titre : Allometric models for estimating tree volume and aboveground biomass in lowland forests of Tanzania Type de document : Article/Communication Auteurs : Wilson Ancelm Mugasha, Auteur ; Ezekiel Edward Mwakalukwa, Auteur ; Emannuel Luoga, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : 13 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes IGN] allométrie [Termes IGN] biomasse aérienne [Termes IGN] densité du bois [Termes IGN] modèle numérique [Termes IGN] Tanzanie [Termes IGN] volume en bois Résumé : (auteur) Models to assist management of lowland forests in Tanzania are in most cases lacking. Using a sample of 60 trees which were destructively harvested from both dry and wet lowland forests of Dindili in Morogoro Region (30 trees) and Rondo in Lindi Region (30 trees), respectively, this study developed site specific and general models for estimating total tree volume and aboveground biomass. Specifically the study developed (i) height-diameter (ht-dbh) models for trees found in the two sites, (ii) total, merchantable, and branches volume models, and (iii) total and sectional aboveground biomass models of trees found in the two study sites. The findings show that site specific ht-dbh model appears to be suitable in estimating tree height since the tree allometry was found to differ significantly between studied forests. The developed general volume models yielded unbiased mean prediction error and hence can adequately be applied to estimate tree volume in dry and wet lowland forests in Tanzania. General aboveground biomass model appears to yield biased estimates; hence, it is not suitable when accurate results are required. In this case, site specific biomass allometric models are recommended. Biomass allometric models which include basic wood density are highly recommended for improved estimates accuracy when such information is available. Numéro de notice : A2016--110 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1155/2016/8076271 En ligne : http://dx.doi.org/10.1155/2016/8076271 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84741 [article]