Benjamin Engler

Prof. Dr. Benjamin Engler

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
2 August 2024 in Current Forestry Reports
Verified
Journal Article
Open access
PDF file
BEBenjamin Engler
Benjamin Engler
GHGwendolin Hartmann
Gwendolin Hartmann
Piotr S. MederskiPiotr S. Mederski
Piotr S. Mederski
LBLeo Gallus Bont
Leo Gallus Bont
Gianni PicchiGianni Picchi
Gianni Picchi
Janine SchweierJanine Schweier
Janine Schweier
Purpose of the Review: The aim of the review was to better understand the impacts of the dominant harvesting systems in Europe, namely harvester-forwarder (HFW), chainsaw-skidder (CSK), and chainsaw-cable yarder (CCY). Furthermore, we aimed to learn how the impact categories environment, economy, ergonomics, people and society, and quality optimization are related to the European biogeographical regions Boreal, Continental, Alpine, and Mediterranean forests. Based on this, key drivers for the future development of forest operations were identified. It was specifically not the aim to develop models through the outcome of this study. Recent Findings: HFW harvesting systems dominate in Boreal (99%) and Continental forests (72%). In Alpine forests the most relevant, even when not dominant, harvesting system is CCY (47%). CSK harvesting systems are applied in all biogeographical regions, with a focus on Mediterranean (70%), Alpine (50%) and Continental (22%) forests. Major drivers for harvesting system development were identified: (i) increased environmental constraints, (ii) increased complexity of harvesting caused by an increasing area of mixed-forest stands, (iii) increased resource efficiency fostered by a growing demand for wood products, (iv) a reduced available work force resulting from heightened competition for skilled worker and an aging population, and (v) more transparent work and material flows through the introduction of digitalization. Summary: A literature review from 110 journal articles and 975 datasets from four biogeographical regions in Europe, specifically from Estonia, Germany, Spain and Switzerland was performed. Most of the reviewed papers included information about economic or environmental impacts, while ergonomics, quality optimization and societal aspects were less in focus. The impacts from the HFW, CSK and CCY harvesting systems were evaluated against regional conditions. Unfortunately, a common understanding of harvesting system evaluation is missing, which limits the comparability of results between different regions.

31 August 2022 in Forests
Verified
Journal Article
Open access
PDF file
Raffaele SpinelliRaffaele Spinelli
Raffaele Spinelli
NMNatascia Magagnotti
Natascia Magagnotti
GCGiulio Cosola
Giulio Cosola
BEBenjamin Engler
Benjamin Engler
SLStefan Leitner
Stefan Leitner
Renato VidoniRenato Vidoni
Renato Vidoni
A survey was conducted on 12 cable yarding operations in northern Italy, with the purpose of determining fuel consumption and time use. The observation unit was the individual operation, intended as all the activities needed to complete the harvesting of a sale (mean = 500 m3 of timber). All teams were equipped with a tower yarder, an excavator-based loader or processor and a truck or a tractor with trailer, if intermediate transportation to a larger roadside landing (two-staging) was required. The crew size was 3 or 4 operators. Time and fuel use were recorded separately for the following tasks: relocation; set up & dismantle; commuting; yarding; processing and/or loading; major delay events. Fuel consumption averaged 5.1 L m−3, of which 2.2 L m−3 was incurred by two-staging. In general, the yarder accounted for less than half the total fuel consumption of the operation: the processor was indeed the main consumer. Relocation had a very small incidence on time and fuel use. Set up and dismantle did not incur significant fuel consumption but occupied a meaningful share of total time (mean = 22%). Commuting also incurred unexpectedly large (and generally neglected) fuel and time use—with means at 13% and 7%, respectively. Technology developments aimed at reducing fuel consumption should target both main consumers: the yarder as well as the excavator-based processor. Significant benefits would also be achieved through improved planning and infrastructure development, aimed at minimizing the need for intermediate transportation (i.e. two-staging).

1 January 2024 in Silva Fennica
Verified
Journal Article
Open access
PDF file
AKAlexander Kaulen
Alexander Kaulen
BEBenjamin Engler
Benjamin Engler
Thomas PurfürstThomas Purfürst
Thomas Purfürst
Highly mechanized timber harvesting and timber logistics emit CO2. In turn, the provided timber stores CO2 from the atmosphere as biogenic carbon. This basic assumption resulted in the calculation of net carbon storage of supplied timber. For this, we first developed a formula that represents the carbon content of freshly harvested timber. Coniferous wood contains about 734 kg CO2 m-3 and deciduous wood about 1000 CO2 m-3. Contrary to this, CO2 emissions from trucks, harvesters, and forwarders were calculated using the variable parameters for actual diesel consumption and the distance to the sawmill and constant parameters for the transport of the machine to the stand, lubricants, transport of operators, loading, and fabrication, supply, and maintenance. The method was tested on an actual harvest. The principal findings are that the method is practical, the net carbon storage of the supplied timber is reduced by 1.5% to 5% by harvesting and transport activities, and timber logistics is the largest contributor to emissions. The CO2 emissions for harvesters and forwarders are about 4 kg CO2 m-3, and for downstream timber logistics across all assortments and distances is 11 kg CO2 m-3. We conclude that the emissions are low, vis-a-vis the storage capacity. Emissions and a standardized calculation model are imperative. The model developed here for mapping the net carbon storage of roundwood highlights the climate protection performance of timber and contributes to optimizing climate-friendly timber supply chains.

12 November 2020 in International Journal of Forest Engineering
Verified
Journal Article
Closed access
BEBenjamin Engler
Benjamin Engler
SHStephan Hoffmann
Stephan Hoffmann
MZMatthias Zscheile
Matthias Zscheile
Driving forest machines on wet soils causes irreversible soil compaction, often associated with intensive rut formation and inaccessibility of wheeled forest machines for future forest operations. The German forestry equipment manufacturer FHS, Forsttechnik Handel & Service GmbH, engineered a forwarder, the Trac 81/11, equipped with conventional, well-proved bogie-axles embraced by a closed rubber track. At the center of the bogie-axle, four additional supportive rollers are placed to increase the load-carrying section between the tires of the bogie-axle. The study aimed to characterize the principle concept and the trafficability of the forwarder by analyzing the footprint area, the contact pressure, the rut formation on forest sites and the slippage during driving. Therefore, the effective contact area was measured on steel plates and rut formation was analyzed on a case study basis. Results showed that the supportive rollers increase the contact surface area by about 1/3. By this, a decrease of peak loads below the wheels and a more homogenous load distribution were observed. However, the contact surface area is still clearly divided into three parts; the area between the supportive rollers and the wheels does not take any load. Results of the rut formation were diverse: After 20 passes with 26,700 kg total mass, rut depth varied between 12.6 and 212.5 mm. Overall, the new undercarriage concept of FHS demonstrated a generally positive performance. The engineered forwarder contributes to reduce the environmental impact associated with log extraction.

12 November 2025 in Croatian journal of forest engineering
Verified
Journal Article
Open access
FBFerréol Berendt
Ferréol Berendt
IBIman Bajalan
Iman Bajalan
FAFabian Arndt
Fabian Arndt
BEBenjamin Engler
Benjamin Engler
TCTobias Cremer
Tobias Cremer
Accurate assessment of log and stack volumes is essential for predicting product yields and supporting decision-making in the forest industry. Despite the need to understand stack and log measurement metrics, this remains challenging due to new technological trends, complicated measurement methods, significant variation between regions, species, products, sizes, and age classifications, and prevailing misconceptions about measurement units. The main aim of this study was to compare several currently used log and timber stack volume measurement methods. Additionally, volume conversion factors from gross stack volume to net solid wood volume were calculated. To this end, Scots pine (Pinus sylvestris L.) stands were harvested using a John Deere 1170G harvester. The wood was measured using different methods and technology, including opto-electronic log measurements, manual volumetric timber stack measurements, and photo-optical stack measurements for sawmill, pallet, and other industrial partners. Conversion factors were calculated (dividing the solid wood volume under bark by the gross stacked volume over bark, including air spaces) to convert the gross stack volume into a net or solid wood volume under bark, which is an important unit for roundwood purchasing. The log measurement results showed significant differences between the various wood measurement methods across all assortments. In particular, significant differences were observed between harvester and sawmill measurements. Additionally, a comparison between manual sectional stack measurement and truck load scanning at the sawmill revealed significant differences for the medium-density fibreboard (MDF) timber assortment. Conversion factors ranged from 0.50 to 0.66, with a mean of 0.596, lower for LAS 3 m timber and higher for LAK timber. The results will contribute to a better understanding and general harmonisation of different methods for measuring stacks based on a series of studies of Scots pine assortments.

26 August 2026 in Blockchains
Verified
Journal Article
Open access
PDF file
LSLukas Stopfer
Lukas Stopfer
BEBenjamin Engler
Benjamin Engler
Thomas PurfürstThomas Purfürst
Thomas Purfürst
Blockchain technology (BCT) is often discussed as digital support for timber traceability in the context of the EU Deforestation-Free Products Regulation (EUDR), which requires operators and traders to demonstrate legality, deforestation-free production, geolocation at the forest parcel level, and verifiable supply chain documentation from 30 December 2026, with an extended timeline for micro, small, and medium-sized enterprises (SMEs) until 30 June 2027. This study assesses where BCT can realistically add value in timber supply chains under operational forestry conditions and identifies the necessary technical, organizational, and legal prerequisites. A combination of a targeted literature review and empirical input from experts in the forestry and timber industry, including guided expert web-conferencing interviews (n = 41), an online survey (n = 69 completed responses), and a transdisciplinary workshop (n = 18) was utilized to obtain a comprehensive overview of industry perspectives. Qualitative data from interviews and workshop sessions were analyzed using structured qualitative content analysis, while survey data were evaluated using descriptive statistics. The expected benefits are associated with the introduction of tamper-proof timber harvesting practices and cross-organizational verification mechanisms. To address the discrepancy between biological uncertainty and digital rigidity, the study proposes a dynamic allocation model adapted from the energy sector that distinguishes between fixed and variable wood capacities to automate logistical planning via smart contracts. However, respondents emphasize that practical obstacles, such as limited digital maturity in forestry, fragmented data infrastructures across the supply chain, and unresolved issues of data sovereignty hinder the implementation of BCT. BCT alone is unable to resolve the problem of weak physical-digital identity continuity, a phenomenon widely known as the oracle problem; however, coupling the ledger with physical or biological anchors (e.g., photo-optical, automated inkjet marking identification) can re-establish this physical–digital continuity and thereby resolve the oracle problem. The results demonstrate that blockchain acts most plausibly as a supporting component within hybrid traceability architectures that prioritize event-based authentication, off-chain data processing where appropriate, and integration with existing certification systems. The study highlights the necessity of defining distinct organizational roles and responsibilities while integrating user-centric digital solutions tailored specifically to small and medium-sized enterprises (SMEs).