Simulation of harvester productivity in selective and boom-corridor thinning of young forests

Forest management practices may change in the future, due to increases in the extraction of forest fuel in first thinnings. Simulation models can be used to aid in developing new harvesting systems. We used such an approach to assess the productivity of innovative systems in various thinnings of young stands with wide ranges of mean breast height diameter (1.5–15.6 cm), stems per hectare (1000–19,100), and mean height (2.3–14.6 m). The results show that selective multiple-tree-handling increases productivity by 20–46% compared to single-tree-handling. If the trees are cut in boom-corridors (10×1 or 2 m strips between strip roads), productivity increases up to 41%, compared to selective multiple-tree-handling. Moreover, if the trees are felled using area-based felling systems, productivity increases by 33–199%, compared to selective multiple-tree-handling. For any given harvesting intensity, productivity increased the most in the densest stands with small trees. The results were used to derive time consumption functions. Comparisons with time study results suggest that our simulation model successfully mimicked productivity in real-life forest operations, hence the model and derived functions should be useful for cost calculations and evaluating forest management scenarios in diverse stands

Do Flood Mitigation and Natural Habitat Protection Employment Reduce Youth Offending?

The present study examines the association between employment and offending for a sample of young offenders who are paid to work in a pilot program known as the Skill Mill. First, we analyse a sample of 39 youths over a period of 10 years (40 quarters) to determine whether Skill Mill employed youth are more likely to desist from offending than a control group of youth who are not employed in the Skill Mill. Those youths employed by the Skill Mill committed 1.12 fewer offences per quarter than the control group (p<0.001). In addition, offending rates among the Skill Mill youths decreased by 0.99 offences per quarter after they began work (p<0.001). Next, we review results from semi-structured interviews with current Skill Mill employees and their supervisor that helps to unpack why the Skill Mill has been successful in promoting desistance. We conclude that programs like the Skill Mill can mark an important turning point, and more specifically, a hook for change in the lives of young offenders