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SYNOPSISTree volume and biomass equations developed for Kitulangalo area in Morogoro, Tanzania ignored small branches and small trees. Consequently, this study was carried out to develop new individual tree volume and biomass equations, and assess current regeneration status, biodiversity and yield ofmiombo woodlands of the area. Volume and biomass equations based on stump diameter for the estimation of volume and biomass of felled trees were also developed. A total of 30 trees were measured for stump diameter (StD), diameter at breast height (dbh) and total height and felled for the determination of volume and biomass. Different tree stem, branch and total volume and biomass models were then fitted.For the determination of current regeneration status, biodiversity and yield, data were collected from three strata: (a) Forest Reserve managed by the Central Government, (b) Forest Reserve under Sokoine University of Agriculture (SUA) and (c) General land (free access by the public). In each stratum, temporary concentric circular sample plots were laid out on transects at 150 m intervals for a 1% sampling intensity. Stand variables such as number of stems per ha, basal area, biomass, volume and plant diversity, were computed for each stratum. The study has revealed the presence of average volumes (m 3 ha· 1 ) and basal areas (m 2 ha· 1 ) of: 76.02 ± 9.14 and 9.13 ± 0.78 for the Government forest reserve, 76.03 ± 9.34 and 8.95 ± 0.73 for SUA forest reserve, and 43.9 ± 7.75 and 7.78 ± 1.1 for general land forest. The respective biomass values were 43.56 ± 7.06, 41.40 ± 4.90 and 29.31 ± 6.56 t ha· 1 • Tree species composition and regeneration status revealed that though disturbed, the public land species composition is not different from the other two strata. More studies should be done on the nursing ofthe abundant regeneration in the disturbed general land. The developed volume and biomass models are recommended to be used for the miombo woodlands at Kitulangalo area especially where small trees ( < 8 em dbh) are involved.

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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 household 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.

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This study examined the effects of planting spacing on growth, yield, and wood properties of teak planted at square spacing regimes of 2 m, 3 m, and 4 m at Longuza Forest Plantation, Tanzania. To achieve this, tree, stand, and wood properties were studied at age of 14 years. Results showed that diameter at breast height and total height increased with increasing spacing. Mean annual increment increased significantly with increasing spacing while spacing did not have significant effect on total volume production and basal area. Basic density is also not affected by spacing while heartwood proportion increases as planting spacing increases. All studied wood properties (modulus of rupture, modulus of elasticity, compression strength tangential to grain, and shear tangential to the grain) except cleavage tangential to grain were not significantly affected by increasing spacing. It is recommended to use the spacing of 3 × 3 m, but if thinning can be done before onset of competition at 5 years, the currently used spacing of 2.5 × 2.5 m can still be used. However, the use of a spacing of 4 × 4 m can give at least 50% heartwood at shorter rotation age of 30 years.

Frequent nutrient removals accompanying wood and crop harvests from rotational woodlot systems may contribute to declining site productivity and sustainability because of soil nutrient depletion. However, selecting for nutrient-efficient tree species may well sustain productivity under this system. To test this hypothesis, a randomized complete block experiment was adopted to assess effects of five tree species on soil nutrients status, nutrient use efficiency and wood yield in semi-arid Tanzania. After 5 years rotation, top soils under Gliricidia sepium (Jaqua), Acacia polyacantha Willd. and Acacia mangium Willd. were the most fertile with soil organic carbon and exchangeable cation status raised close to those in natural Miombo systems. Soil inorganic N and extractable P levels reached sufficiency levels for subsequent maize culture. Wood productivity in tree fallows averaged three times higher than that of Miombo woodlands indicating the high potential of the woodlot system to supply fuelwood, and consequently relieve harvesting pressures on the natural forests. Acacia crassicarpa A. Cunn. ex Benth. produced the most wood (51 Mg ha À1 ) at low nutrient ''costs'' presumably due to high nutrient use efficiency. Wood yield of this species was 42 and 120% greater than that of A. polyacantha and A. nilotica, respectively, but contained comparatively less nutrients (42-60% less for P, K, and Ca). Gliricidia sepium and A. polyacantha returned the largest amount of nutrients through slash at harvests. Of all test species, A. crassicarpa exhibited the most promise to sustain wood production under rotational woodlot systems due to relatively high productivity and low nutrient export at harvest.