Understanding willingness to harvest (WTH) is essential to assessing the social availability of woody biomass from private land. Currently, the only economically feasible way to harvest woody biomass is in conjunction with sawlogs. We examined WTH sawlogs and woody biomass from owners of family forests using data from a survey of Missouri forest owners. While their WTH increased with revenue expected from woody biomass, revenue expected from sawlogs was a stronger influence. Incentive payments for woody biomass thus are unlikely to increase its supply, and the social availability of woody biomass will remain limited unless sawlog prices rise significantly.

An interspecific hybrid Jatropha curcas (Jc) × Jatropha integerrima (Ji) was developed between jatropha (Jc) from Mexico and Ji from Thailand. Jc is a large canopy plant with soft wood, while Ji is a tall plant with semi-hard wood. The F1 hybrid and their parents were grown under field conditions at a spacing of 1 m × 1.5 m. One-year-old plants were harvested and determined for biomass yield, calorific value and chemical composition of wood, as well as for heterosis (hybrid vigour) of these characters. The F1 plants gave an average fresh wood weight of 18.07 kg/plant, a moisture content of 46.56%, a dry wood weight of 9.56 kg/plant and a wood density of 0.62 g/cm3. The F1 hybrid had less ash (2.60%) than Jc (6.93%), but a higher heat value of wood (18.73 MJ/kg) than Jc (17.77 MJ/kg). Heterosis over mid-parent was very high and positive in dry wood weight, fresh wood weight and number of secondary branches at 542, 310 and 450%, respectively, while negative heterosis was found in moisture content ( − 24.86%). The desirable traits found in the F1 hybrid can be fixed by cutting propagation of the selected plants.

Although fire is occurring at greater frequencies and spatial scales in the moist tropics, few studies have examined the ecological impacts of fire in tropical montane cloud forest (TMCF). This study, conducted in the Chimalapas region of Oaxaca, Mexico, documents changes in live tree biomass, live fine-root biomass, and fallen and standing dead wood 4 y following deep ground fires occurring in TMCF during the 1997–98 El Niño Southern Oscillation event. Forests growing on two different substrates (metamorphic and sedimentary) and having three different statures (mean canopy heights: 20–30 m, 15–20 m and 4–6 m) were assessed within six paired plots established on adjacent burned and unburned forest sites. Total live tree biomass was 82% and 88% lower for burned TMCF growing on metamorphic and sedimentary substrates, respectively, compared with unburned TMCF. Nearly 100% of the living biomass was killed in elfin TMCF located on exposed sedimentary limestone at the highest elevations. Live fine-root biomass in the upper organic soil horizon of burned TMCF sites was 49% lower on metamorphic substrates and 77% lower on sedimentary substrates compared with unburned sites. The amount of total dead wood was 3- to 14-fold greater in burned forests compared with unburned forests. These results suggest that first-time fires in relatively undisturbed TMCF can cause dramatic changes in live above- and below-ground biomass at levels greatly exceeding values reported for most lowland tropical rain forests. These patterns may be attributed to the slower decomposition rates and thick organic soils typical of TMCF, combined with the relatively fast drainage associated with steep topography and, in some locations, sedimentary limestone-derived substrates.