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6 result(s) for "Kühmaier, Martin"
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Greenhouse Gas Emissions of the Forest Supply Chain in Austria in the Year 2018
Wood is a renewable product, but for the supply of wood non-renewable materials are also necessary, which can have negative environmental impacts. The objective of this study was to analyze the greenhouse gas (GHG) emissions caused by the forest supply chain in Austria using Life Cycle Assessment (LCA) methods. The forest supply chain consists of several processes like site preparation and tending, harvesting, and transport. In total, 30 relevant forest processes from seedling production until delivery of wood to the plant gate were considered. Results show that in the year 2018, a total of 492,096 t of CO2 eq. were emitted in Austria for harvesting and transportation of 19.2 hm3 of timber. This corresponds to 25.63 kg CO2 eq. per m3. At 77%, transport accounts for the largest share of emissions within the supply chain. Extraction causes 14% of emissions, felling and processing cause 5%, and chipping causes 4%. GHG emissions for felling, delimbing, and crosscutting are much lower when using a chainsaw compared to harvester. The high numbers for the transport can be explained by the high transportation distances. Especially for the transportation of wood, it is necessary to find more climate-friendly solutions from a technical and organizational point of view. The provision of wood is climate-friendly, and its use enables the substitution of fossil fuels or materials with higher negative effects on climate change such as aluminum, steel, or concrete.
Potential of Apple Vision Pro for Accurate Tree Diameter Measurements in Forests
The determination of diameter at breast height (DBH) is critical in forestry, serving as a key metric for deriving various parameters, including tree volume. Light Detection and Ranging (LiDAR) technology has been increasingly employed in forest inventories, and the development of cost-effective, user-friendly smartphone and tablet applications (apps) has expanded its broader use. Among these are augmented reality (AR) apps, which have already been tested on mobile devices for their accuracy in measuring forest attributes. In February 2024, Apple introduced the Mixed-Reality Interface (MRITF) via the Apple Vision Pro (AVP), offering sensor capabilities for field data collection. In this study, two apps using the AVP were tested for DBH measurement on 182 trees across 22 sample plots in a near-natural forest, against caliper-based reference measurements. Compared with the reference measurements, both apps exhibited a slight underestimation bias of −1.00 cm and −1.07 cm, and the root-mean-square error (RMSE) was 3.14 cm and 2.34 cm, respectively. The coefficient of determination (R2) between the reference data and the measurements obtained by the two apps was 0.959 and 0.978. The AVP demonstrated its potential as a reliable field tool for DBH measurement, performing consistently across varying terrain.
Timber Tracking in a Mountain Forest Supply Chain: A Case Study to Analyze Functionality, Bottlenecks, Risks, and Costs
Digital transformation of the timber supply chain is more relevant at present than ever before. Timber tracking is one example of digital transformation, and can be performed in various locations, from the forest to the mill, or even beyond, to the final timber product. The integration of new technologies in the forestry and timber industries should contribute to enhancing supply chain efficiency and safety. For this purpose, a new timber tracking and processing system was tested by integrating RFID (Radio Frequency IDentification) technology with digital survey tools and intelligent machines, into a smart timber supply chain. A case study on this process was carried out in a mountain forest in Austria. The tags were used to link information to single items (trees and logs) and transfer relevant data (species, diameter, length, volume, defects, density, stiffness, branchiness, etc.), throughout the whole supply chain. The performance of the technology was analyzed by means of process flow, bottleneck, and risk analyses. Fourteen spruce trees went through the supply chain process from the forest stand to the log yard, monitored by the new timber tracking and processing system. The results revealed that the new system is useful for transferring information through the timber supply chain, and the system costs remained at a normal market level. The weakest point in the supply chain was the processing of the trees by the intelligent prototype processor. A high error rate and low durability lead to higher idling time and harvesting cost, but the findings of this study can be used to further improve this system. All other processes worked well and were at a marketable level.
Capacity Planning of Timber Harvesting in Windthrow Areas
Digitization can help the forest industry to improve cost efficiency and to reduce possible environmental impacts. In the context of this study, models were implemented using the example of windthrow processing, which enables a capacity planning for carrying out timber harvesting. For capacity planning, it is necessary to estimate the time required by the harvesting systems. For this purpose, existing productivity models were analyzed, the models were validated and adjusted, and the time required for each harvesting system and calamity area was calculated using stand and terrain parameters. Depending on the scenario and the preferred harvesting system, the time for harvesting the timber in an almost 200-hectare windthrow area in a case study region in Carinthia (Austria) varied. The harvesting with cable yarder and tractor takes about 26,000 machine hours and 86,000 man-hours. Harvesting operations with cable yarder and harvester-forwarder has proven to be the most productive with a duration of around 20,000 machine hours and 70,000 man-hours. Depending on the scenario, in windthrow areas, forest workers are needed for 28 to 42 min to fell, delimb, buck and extract 1 m3 of timber to the forest landing.
Using Conjoint Analyses to Improve Cable Yarder Design Characteristics: An Austrian Yarder Case Study to Advance Cost-Effective Extraction
Steep country harvesting has been identified as the main bottleneck to achieving greater profitability in the forestry sector of New Zealand and Australia. An improvement of efficiency, work safety and environmental sustainability should be realized by developing an advanced steep terrain timber harvesting system based on innovative Austrian technology. To identify the best suitable configuration of a cable yarder for steep terrain harvesting, user preferences based on an online survey (conjoint analysis) have been evaluated to answer the following questions: (1) What attributes of a new yarder design are most important to consumers? (2) Which criteria do stakeholders consider when selecting a cable yarder? (3) What are the weights representing the relative importance of criteria? Using eight specific design scenarios a fourth question, being which cable yarder concept is the best, was also answered. This case study shows that conjoint analyses is an effective tool to assess, rate and subsequently integrate design characteristics. Based on the results of the analysis, a cable yarder prototype will be manufactured in Austria and transferred to New Zealand for testing and demonstration.