Chanfuta (Afzelia quanzensis Welw.), Jambire (Millettia stuhlmannii Taub.) and Umbila (Pterocarpus angolensis D.C.) are, among others, three of the main tropical tree species producing commercial timber in Mozambique. The present study employed destructive biomass estimation methods at three localities in Mozambique (Inhaminga, Mavume, and Tome) to acquire data on the mean diameter at breast height (DBH), and height of trees sampled in 21 stands each of Chanfuta and Jambire, and 15 stands of Umbila. Mean diameter at breast height (DBH) (ob) for Chanfuta, Jambire, and Umbila was: 33.8 ± 12.6 (range 13.5–61.1), 33.4 ± 7.4 (range 21.0–52.2), and 27.0 ± 9.5 (range 14.0–46.5) cm. The mean total values for biomass (kg) of trees of Chanfuta, Jambire, and Umbila trees were 864, 1016, and 321 respectively. The mean percentages of total tree biomass as stem, branch and leaf respectively were 54, 43, and 3 for Chanfuta; 77, 22, and 1 for Jambire; and 46, 51, and 3 for Umbila. The best fit species-specific equation for estimating total above ground biomass (AGB) was the power equation with only DBH considered as independent variable yielding coefficient of determination (R²) ranging from 0.89 to 0.97. At stand level, a total mean of 27.3 tons ha⁻¹ biomass was determined of which studied species represented 94.6%. At plot level, total mean biomass for Jambire was 11.8 tons ha⁻¹, Chanfuta and Umbila 9.9 and 4.1 tons ha⁻¹ respectively. The developed power equation fitted total and stem biomass data well and could be used for biomass prediction of the studied species in Mozambique.

Today there is an increasing demand for biomass for use in energy production. In this study we investigated stumps and roots from six poplar (Populus sp.) stands growing on former farmland in Sweden, situated between latitudes 55 and 60°N. The mean age of the poplar was 20 years (range 16–23), the mean stand density 1151 stems ha⁻¹ (range 361–3279), and the mean diameter at breast height (over bark) 288 mm (range 81–574). All poplar stands were on clay soils (light and medium clay and light clay tills).The mean dry mass weight of the 72 excavated stumps was 45 ± 39 kg (range 1–185), with the roots ≥ 50 mm weighing 14 ± 16 kg (range 0.2–87). Dry mean stump weight represented 21% (by dry weight) of the stem. The mean total dry weight per hectare for stumps amounted to 34.9 ± 21.8 (range 12.9–66.9) tons and the equivalent value for roots was 12.0 ± 9.6 (range 4.7–10.9) tons. The excavation of below-ground biomass can either focus on the stump or the stump and parts of the root system. Depending on the combination of soil type and soil moisture the weight of soil adhering to stumps and the cleaning requirements will vary.

An equation was constructed to estimate the stem volume of Norway spruce (Picea abies (L.) Karst.) in 145 stands growing on former farmland in Sweden (Latitude 56–63° N). The mean total age was 40 ± 13 (range 17–91) years, the mean diameter at breast height (ob) was 15 ± 4 (range 5–27) cm and the mean density was 1621 ± 902 (range 100–7600) stems ha⁻¹. The equation which fits the data best used the diameter at breast height and total stem height as predictive variables. Merchantable volume equations for the estimation of commercial volume for any top diameter and bole length were developed. Soil types in the stands were sediments (coarse sand, fine sand and silt and heavy, medium and light clay), tills (sandy, fine sandy and silty) and peat. The standing volume was calculated; the mean was 253 ± 103 (range 26–507) m³ ha⁻¹ with a MAI (mean annual increment) of 6.9±3.5 (range 1.3–16.7) m³ ha⁻¹ year⁻¹. There were statistically significant differences between MAI and coarse sand, sand and silt, light clay, peat and silty till soils. Spruce stands growing on silty tills had the lowest MAI (4.94 ± 2.27 m³ ha⁻¹ year⁻¹) and light clay, fine sand and silt and peat the highest (7.62 ± 4.24, 7.46 ± 3.33 and 8.67 ± 2.83 m³ ha⁻¹ year⁻¹).

Swedish owners of poplar stands are interested in both the wood quality and the use of poplars that are soon to be harvested. An important concern is the frequency of false heartwood (FHW) in the stems. We have presented an overview of the factors causing discolored wood as well as the industrial use and quality of the end products. We have studied poplar stems growing at 22 sites in Sweden between latitudes 55° N and 60° N. The mean age of the poplar was 23 years (range 14–41), the mean stand density 1011 stems ha⁻¹ (range 155–3493) and the diameter at breast height (DBH) (over bark) 246 mm (range 121–447). All stands were growing on clay soils (light and medium clay and light clay tills). All of the sampled stems (42) contained false heartwood. At 0%–50% of stem height, all sampled trees were discolored and at 90% of stem height, 33% were discolored. The percentage of false heartwood area by stem area was highest at 1% and 10% of stem height (26.6% and 24.7% respectively). The “FHW” part of the stem had a radius of 47 mm (range 9–93) at 30% of stem height, which corresponds to 50% of the total stem radius. A log of six meters represents about 30% of stem height. Equations describing the correlation between DBH and the diameter of FHW at different stem heights (1%, 10%, 30%, 50%, 70% and 90%) and table describing FHW volume % by total stem volume at the first 50% of stem height were constructed. These might be helpful for estimating the percentage of fresh wood in a stem. However, most of the fast-growing poplars will be harvested as biofuel.