Browsing by Author "Iddi, S."
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Item Comparison of volume production, basic density and stem quality between acacia mangium and acacia Aubicuuformis grown in Zanzibar(Forest Research Institute Malaysia, 1997) Ali, M.S.; Malimbwi, R. E.; Iddi, S.Comparison of volume production, basic density and stem quality between Acacia mangium and Acacia auriculiformis grown in Zanzibar. Volume production, basic density and stem quality of 6-y-old Acacia mangium and A. auriculiformis grown in Zanzibar were compared. Twenty-one plots (11 plots for Acacia mangium and 10 for A. auriculiformis ) were established and used for data collection. From each plot one to two trees free from obvious defects were selected for basic density determination. Cores were then extracted from the selected trees using an increment borer. Basic density of the cores was determined by the water displacement method. Height and diameter data were used for volume estimation. Stem quality was assessed using the scoring method, 4 being the best and 1 the worst. At age 6 y, diameter and height growth did not vary significantly (p = 0.05) between the two species. More than 50 m3 ha"1 volume production was achieved in both species. The average volume weighted basic density values for A. mangium and A. auriculiformis were 570 kgm"3 and 617 kgm"3 respectively. The basic density values for the two species differed significantly (p = 0.05). Stem quality was better in A. mangium than in A. auriculiformis. Based on density, A. auriculiformis can be recommended for fuelwood production whereas A. mangium should be recommended for transmission and building poles due to its good stem form.Item Does participatory forest management promote sustain- able forest utilisation in Tanzania(BioOne, 2014) Treue, T.; Ngaga, Yonika M.; Meilby, H.; Lund, J.F.; Kajembe, George C.; Iddi, S.; Blomley, T.; Theilade, I.; Chamshama, S.A.O.; Skeie, K.; Njana, M.A.; Ngowi, S.E.; Isango, J.A.K.; Burgess, N.D.Over the past 20 years, Participatory Forest Management (PFM) has become a dominant forest management strategy in Tanzania, covering more than 4.1 million hectares. Sustainable forest use and supply of wood products to local people are major aims of PFM. This paper assesses the sustainability of forest utilisation under PFM, using estimates of forest condition and extraction rates based on forest inventories and 480 house- hold surveys from 12 forests; seven under Community Based Forest Management (CBFM), three under Joint Forest Management (JFM) and two under government management (non-PFM). Extraction of products is intense in forests close to Dar es Salaam, regardless of management regime. Further from Dar es Salaam, harvesting levels in forests under PFM are, with one prominent exception, broadly sustainable. Using GIS data from 116 wards, it is shown that half of the PFM forests in Tanzania are likely to be too small to satisfy current local wood demand.Item Effect of spacing on performance of teak at Longuza, Tanga, Tanzania(Journal of Tropical Forest Science, 1994) Sibomana, G.; Makonda, F. B. S.; Malimbwi, R. E; Chamshama, S. A. O.; Iddi, S.The performance of teak ( Tectona grandis ) planted at four square spacings ( 1 .5, 2.0, 2.5 and 3.0 m) at Longuza, Tanga, in Tanzania was assessed. The variables studied were diameter at breast height (dbh) , total height and height to the first live branch, survival, number of branches, basal area and volume production at ages 1, 3, 7 and 9 y, and basic density and some strength properties at the age of 1 4 y. Results showed that dbh, number of branches, total height, basal area, basic density and some strength properties were significantly affected by spacing (p = 0.05). The diameter at breast height and number of branches increased with increasing spacing, while basal area decreased. All other variables were not significantly affected by spacing. A spacing of 3.0 m resulted in large diameter trees and later thinnings, with less total volume per hectare. The current spacing of 2 m resulted in higher volume per hectare of small sized trees which could be improved by thinning. It is recommended to continue with this spacing and the current thinning schedule until information on the economic implications of alternative regimes is available.Item Infestation Density of Eucalyptus Gall Wasp, Leptocybe invasa Fisher and La Salle (Hymenoptera: Eulophidae) on Five Commercially Grown Eucalyptus Species in Tanzania(Taylor & Franci, 2014) Petro, R.; Madoffe, S.S.; Iddi, S.This study explores infestation density of Leptocybe invasa on five commercially grown Eucalyptus species in Coastal, Plateaux, and Southern Highlands agroecological zones of Tanzania. Infestation density between agroecological zones, Eucalyptus species, age classes and tree crown parts, relationship between stand altitudes and the magnitude of infestation, damage index, species age, and abundance of L. invasa on different Eucalyptus species were examined. There were significant differences in infestation between zones and Eucalyptus species. Eucalyptus tereticornis was more affected, followed by E. camaldulensis, andE. saligna was the least while E. grandis and E. citriodora were not affected. No significant differences in damage between different crown parts were observed.Treeswithageof1–3yrweredamagedmorethanthoseof age 4–6 yr. Pest infestation increased with an increase of L. invasa abundance but decreased with an increase of altitudes. Control efforts needs to focus on controlling the spread of the pest, using silvicultural methods and planting resistant Eucalyptus species.Item Survival, growth and wood density of Pinus Kesiya provenances at Buhindi, Mwanza, Tanzania(Forest Research Institute Malaysia, 1999) Chamshama, S. A. O.; Chingonikaya, E. E.; Iddi, S.; Mugasha, A. G.; Nshubemukiand, L.; Malimbwi, R. E.he objective of this study was to evaluate the performance of 13 Pinus hesiya provenances at Buhindi, Mwanza, Tanzania. Periodic data were collected on survival, breast height diameter and height. A final assessment was carried out at 18.3 y for survival, breast height diameter, height, stem form and basic density. Except for wood basic density, all other variables differed significantly (p<0.05) between provenances. The following provenances with satisfactory performance are recommended for small-scale planting at Buhindi: Benguet Kabayan and ZambalesItem Survival, growth, stem form and wood basic density of five Pinus Merkusii provenances at Buhindi, Mwanza, Tanzania(1998) Mugasha, A. G.; Mgalla, H.A.; Iddi, S.; Nshubemuki, L.; Chamshama, S.A.O.; Malimbwi, R. E.The performance of 16 Pinus oocarpa (including 5 now reclassified as Pinus patula spp. tecunumanii) provenances at Buhindi Mwanza, Tanzania: is evaluated in terms of survival, height growth, breast height diameter, basal area per ha, wood basic density and stem form. The final assessment was carried out at the age of 22 years. The main results of the study were: – Before angular transformation, survival varied from 77% (Rafael, Nicaragua) to 56% (Conacaste, Guatemala). However no significant difference (P >0.05) in survival was detected after such transformation. – Height growth showed significant differences (P< 0.05) at all ages. At 22 years the outstanding provenances were Siguatepeque (Honduras), Rafael (Nicaragua), and Zamorano (Honduras). Least height growth was shown by Bonete (Nicaragua) provenance. – Significant differences (P< 0.05) were detected in breast height diameter. Outstanding provenances were Yucul, Camelias (Nicaragua) and Mt. Pine Ridge-K49 (Belize). Least performers were Zamorano (Honduras) and Lagulnilla (Guatemala) provenances. – Significant differences (P< 0.05) were detected in basal area per ha development. The Bucaral (Guatemala) provenance was outstanding while least basal area development was recorded in the Conacaste, Lagunilla (Guatemala) and Siguatepeque (Honduras) provenances. – The Bucaral (Guatemala) provenance was significantly superior (P< 0.05) in wood basic density. Least wood basic density values were recorded from Camelias, Yucul, Rafael, Junquillo (Nicaragua), Angeles (Honduras) and the Lagumilla (Guatemala) provenances. – No significant differences (P >0.05) in stem form were observed. It is suggested that the 5 Pinus patula SCHIEDE and DEPPE ssp. tecunumanii (EQUILUZ and PERRY) provenances are likely candidates for species diversification in the Lake Victoria zone where the main plantation species is Pinus caribaea. However, noting that more than half of the natural distribution of P. oocarpa occurs outside central America, more provenances need to be tested to cover that extended range. Similarly, the sparse sampling of P. patula ssp. tecunumanii also needs additional representation. Restricting the results of this study to Pinus oocarpa, provenance ranking in diminishing order of performance gives: Bucaral (Guatemala), Zapotillo, Zamorano (Honduras), Chuacus (Guatemala), Siguatepeque (Honduras), Bonete, Junquillo (Nicaragua), Conacaste (Guatemala), Angeles (Honduras) and San Jose (Guatemala); and Lagunilla (Guatemala). In descending order of performance, suitable Pinus patula ssp. tecunumanii provenances are Mt. Pine Ridge (K49), Mt. Pine Ridge (K29), Rafael, Yucul and Camelias (Nicaragua).