Search Results (7)

Recently, the use of powerful and heavy vehicles for timber harvesting on flat or slightly sloping terrains has been widely expanded to provide safe working conditions and high productivity. However, soil disturbances during ground-based mechanized operations in South Korea are not fully investigated and difficult to avoid. Therefore, we compared the soil displacement and compaction (bulk density and hydraulic conductivity) between two different operations: cut-to-length (CTL) logging with a harvester and forwarder, and whole-tree (WTH) logging with a harvester and skidder. After clear-cutting, severe visual disturbances and rut depths were more prevalent in the forwarding trails than in the skidding trails. The CTL harvesting method created larger amounts of slash (6.9 kg/m²) along the trails than the WTH harvesting did (1.8 kg/m²). We found a significant difference in the compaction between the reference and the track and a negative correlation between the slash quantity values and the percentage increase in compaction. Our results showed that using skidding extraction can cause more severe impacts than forwarding extraction. Thus, these results may be helpful in understanding the influence of ground-based CTL and WTH harvesting operations and achieving best practices to minimize the environmental impacts on soil. Full article

We introduce a model that derives a metric to answer the question: what is the expected gain of a staker? We calculate the rewards as the staking return in a Proof-of-Stake (PoS) consensus context. For each period of block validation and by a forward approach, we prove that the interest is given by the ratio of the average staking gain to the total staked coins. Some additional PoS features are considered in the model, such as slash rate and Maximal Extractable Value (MEV), which marks the originality of this approach. In particular, we prove that slashing diminishes the rewards, reflecting the fact that the blockchain can consider stakers to potentially validate incorrectly. Regarding MEV, the approach we have sheds light on the relation between transaction fees and the average staking gain. We illustrate the developed model with Ethereum 2.0 and apply a similar process in a Proof-of-Work consensus context. Full article

Forest harvesting generates variable amounts of residue that pose a fire hazard and a hindrance to regeneration and must be managed accordingly. In South Africa, burning is the most common residue management method, but there is interest in introducing safer and more effective techniques, such as mulching. For that reason, a productivity study was conducted in the Eastern Cape province after a mechanised cut-to-length (harvester and forwarder) harvesting operation to gather information on the productivity, cost, and work quality of the three main alternatives: manual broadcasting, manual broadcasting followed by mulching with an adapted farm tractor and mulching with a purpose-built mulcher. The stem wood residues after harvesting ranged from 12 to 14 ODT/ha. The average time consumption was 16 worker h/ha for manual broadcasting, 3.6 worker h/ha for mulching with a farm tractor, and 0.9 worker h/ha for mulching using a purpose-built mulcher (one pass). Manual broadcasting was the cheapest option, at an average cost of 400 ZAR/ha. Mulching with a farm tractor and a purpose-built mulcher incurred an average cost of 3267 ZAR/ha and 4083 ZAR/ha, respectively. Manual broadcasting achieved a minimal reduction in residue size, with 50% of the slash (branches and stem wood) having a mean length greater than 40 cm. When mulching with a farm tractor was applied, 49% of the slash (branches and stem wood) length was reduced to about 30 cm. When a purpose-built mulcher was used, only 10% of the slash elements exceeded 40 cm in length. Full article

Atmospheric pollutants can corrode heritage materials, especially stone, which can cause a great loss that goes far beyond the economic losses of the degraded materials. Over the past decades, conventional air pollutants have been slashed owing to clean air actions in China, which produces a significant co-benefit for heritage conservation. However, the benefits may be offset by increases in the photochemical oxidants in smog, such as ozone, which damage heritage materials. This study employed dose–response functions to quantify the impacts of air pollutants on the surface recession of the limestone of heritage structures in China, and assessed the potential benefits of air quality improvement for heritage conservation. The results show that the annual recession rate decreased from 9.69 μmy⁻¹ in 2006 to 6.71 μmy⁻¹ in 2020, resulting in a 41.4% increase in the number of heritage sites meeting the ICP Materials (International Co-operative Program on Effects on Materials including Historic and Cultural Monuments) control target of 8 µmy⁻¹ for 2020. The air quality improvement avoided CNY 136.2 million in heritage site maintenance costs. The recession risk shows distinct regional differences; the southern and northwest regions are still at a higher material corrosion level than the northern and Qinghai–Tibet regions. Nationwide, PM₁₀ (particles with aerodynamic diameter less than 10 μm) is the main risk factor responsible for the surface recession of limestone material of heritage structures in China. The study provides evidence for the benefits of air quality improvement for heritage conservation. Further, the study also puts forward policy recommendations for heritage conservation, including assessing pollution risk, promoting heritage conservation through social sustainability, and implementing differentiated conservation strategies. Full article

The Authors conducted a long-term follow-up study of a John Deere 1490 forwarder-mounted bundler owned by a Portuguese company and used for bundling logging residues from fast-growing eucalypt plantations located in Portugal and Spain. The study spanned 7 years, from 2011 to 2016. During this time, the machine clocked over 11,500 h and produced more than 200,000 bundles or 75,000 green tons of biomass. Bundle length was commonly 2.4 m, and bundle mass averaged 350 kg. Overall, the database contained 1752 daily records. Bundling productivity averaged 19 bundles per productive machine hour (meter hour, excluding all major delays). Mechanical availability was very high and averaged 93%. Utilization commonly ranged between 65% and 75%. Use and productivity showed a predictable seasonal trend and a slight decline over time. The latter might be due to wear, but also due to the increasingly challenging conditions faced by the company as the average worksite size sharply decreased from 2011 onwards. While almost extinct elsewhere, bundling seems to thrive in the Iberian plantations, possibly due to the industrial character of both eucalypt farming and bioenergy generation in the region. That allows the reaping of all integration benefits offered by bundling, while the cost of setting up a parallel biomass chain is minimized. Furthermore, bundling seems the ideal technique for efficient residue recovery where slash yields are low and roadside storage space is limited: these are the typical constraints of industrial eucalypt plantations, where planted area is maximized (=little landing space) and the largest possible proportion of the tree mass is turned into pulpwood (=relatively low residue yield). Full article

Ifugao province of the Philippines has a traditional muyong forest system that supplies water and prevents soil erosion of the world-famous Ifugao rice terraces. The socio-political structure of Ifugao has been the key to the maintenance and communal use of land, as well as the muyong forest, without causing excessive damage to the land. Recently, the Ifugao is facing various challenges viz. deforestation, slash-and-burn, introduction of commercial rice, and climate change. The aim of the study is to qualitatively assess the forest management practices in the muyong forest and the way forward to implement the United Nations—Reducing Emissions from Deforestation and Forest Degradation (REDD+) mechanism. Community forestry can be an interesting option to reduce CO₂ emissions from deforestation in Ifugao. This study qualitatively explores the societal problems in the area using focus group discussion (FGD) and key informant interviews (KII). The results show that the terracing lifestyle is at risk, due to mounting economic pressures from the domestic economy. Societal changes are altering the perceptions of the youth in terms of muyong sustainable management. They are threatening the sustainability of the terraces in the long-term because of outward migration and less value given to traditional practices. Furthermore, integration of commercial rice is changing the traditional agricultural system and placing less focus on forest maintenance. This study also discusses potential challenges and opportunities of REDD+ intervention and the role of REDD+ to foster sustainable muyong forest management as well as to find new innovative ways to maintain the Ifugao traditional system while coping with the modernization of the Ifugao economy. Full article

An important task in forest residue recovery operations is to select the most cost-efficient feedstock logistics system for a given distribution of residue piles, road access, and available machinery. Notable considerations include inaccessibility of treatment units to large chip vans and frequent, long-distance mobilization of forestry equipment required to process dispersed residues. In this study, we present optimized biomass feedstock logistics on a tree-shaped road network that take into account the following options: (1) grinding residues at the site of treatment and forwarding ground residues either directly to bioenergy facility or to a concentration yard where they are transshipped to large chip vans, (2) forwarding residues to a concentration yard where they are stored and ground directly into chip vans, and (3) forwarding residues to a nearby grinder location and forwarding the ground materials. A mixed-integer programming model coupled with a network algorithm was developed to solve the problem. The model was applied to recovery operations on a study site in Colorado, USA, and the optimal solution reduced the cost of logistics up to 11% compared to the conventional system. This is an important result because this cost reduction propagates downstream through the biomass supply chain, reducing production costs for bioenergy and bioproducts. Full article