Andreja Đuka

Prof. Andreja Đuka

Department of Forest Engineering, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, Croatia
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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27 July 2020 in Croatian journal of forest engineering
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Journal Article
Open access
Piotr S. MederskiPiotr S. Mederski
Piotr S. Mederski
Stelian Alexandru BorzStelian Alexandru Borz
Stelian Alexandru Borz
Andreja ĐukaAndreja Đuka
Andreja Đuka
ALAndis Lazdiņš
Andis Lazdiņš
The forestry and timber industry are strong sectors in the economies of European countries. The current trend of introducing forestry management that respects the various functions of the forest has created new challenges. However, forestry itself, as well as those challenges, varies in different regions in Europe. The aim of this review paper was to describe forest resources and their potential as well to define challenges in forestry and forest engineering in regions of East Europe. Case studies were selected from four countries: Croatia, Latvia, Poland and Romania. The background data and information of the forest-based sector included: forest resources and forest productivity, forest utilisation, development of forest operations and difficulties in forest management. In the analysed countries, state-owned forestry was represented by at least 45%. Forestry is an important sector in all four countries and future challenges are observed in forest management and forest engineering mainly including: an increase in timber resources, improvement in species composition for better productivity and the introduction of effective mechanised forest operations in pre-commercial thinning. Further improvement of harvester heads is expected for the harvesting of broadleaved species and for young stands. Issues linked to the environment were also recognised as challenging factors: mild winters make it difficult to use CTL technology on wet and sensitive sites. Additionally, dry seasons have a high impact on forest fire frequency, but this can be controlled by effective monitoring systems. Improvement in IT systems used in forest operations should limit the carbon footprint by optimising transport, machine use and limiting fuel use. Finally, innovations are recognised as key issues in the improvement of forest management and forest engineering; therefore, special budgets have been allocated to support science and development.

24 January 2022 in Current Forestry Reports
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Journal Article
Open access
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Piotr S. MederskiPiotr S. Mederski
Piotr S. Mederski
Janine SchweierJanine Schweier
Janine Schweier
Andreja ĐukaAndreja Đuka
Andreja Đuka
Petros A. TsiorasPetros A. Tsioras
Petros A. Tsioras
LBLeo Gallus Bont
Leo Gallus Bont
Mariusz BembenekMariusz Bembenek
Mariusz Bembenek
Purpose of the Review: The application of cut-to-length (CTL) technology for harvesting and processing timber from broadleaved tree species is a challenging process, due to thick branches, stem sweep, forks and high wood density. The objective of this review was to describe the current state of harvester use and characterise the effectiveness of mechanised forest operations for broadleaved and mixed forest stands in Europe, paying particular attention to productivity and product quality aspects. An additional aim was to identify the greatest difficulties associated with harvesting broadleaved tree species today and to indicate future challenges and areas for improvement. Recent Findings: An interest in wider harvester use for broadleaved tree species started after the storm Lothar in France in 1999. Early experiences demonstrated that lower productivity is common when harvesting broadleaved tree species, due to limitations in delimbing and the high frequency of sweep. Initially, modifications were made to harvester heads, while a newly designed head (CTL 40 HW) was later developed within a European project in 2005–2007. Using various heads, very high productivity was achieved in some cases, but log recovery was unsatisfactory, with large tree tops left without delimbing. The delimbing was of lower quality and log length inaccuracy was observed, as well as economic losses due to damage to plywood caused by feed rollers. These issues resulted in a change in harvester head construction, including work on a patent for a head designed specifically for harvesting broadleaved tree species. Summary: The harvester heads that have been developed to date for broadleaved tree species have mainly been used within Central Europe, where the high incidence of broadleaved tree species and their particular morphological features (thick branches and sweep) are a major challenge for CTL technology. There have been many research projects related to this issue: in the last 15 years, there were a few larger initiatives leading to the design and development of harvester heads for broadleaved tree species, with participation from institutions and universities in France, Germany and Poland. There are currently no ongoing initiatives, but the formation of new ones is strongly recommended because today’s forests have a growing share of broadleaved tree species and are being managed to an increasing extent with CTL technology.

31 December 2017 in iForest - Biogeosciences and Forestry
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Journal Article
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Andreja ĐukaAndreja Đuka
Andreja Đuka
Stefano GrigolatoStefano Grigolato
Stefano Grigolato
IPI. Papa
I. Papa
TPT. Pentek
T. Pentek
TPT. Poršinsky
T. Poršinsky
This study aims to define a simple and effective method to calculate skidding distances on steep karst terrain, rich in ground obstacles (stoniness and rockiness) to support decision planning of secondary and primary forest infrastructure network for timber extraction in productive selective cut forests. Variations between geometrical extraction distances and actual distances were highlighted on the operational planning level (i.e., compartment level) through GIS-related calculation models, focusing on cable skidder timber extraction. Automation in defining geometrical and real extraction distances, as well as relative forest openness were achieved by geo-processing workflows in GIS environment. Due to variation of extraction correction factors at the compartment level from a minimum of 1.19 to a maximum of 5.05 in the same management unit, it can be concluded that planning harvesting operations (timber extraction) at operational level should not include the use of correction factors previously obtained for entire terrain (topographical) categories, sub-categories or even management units.

26 April 2022 in Croatian journal of forest engineering
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Journal Article
Open access
Kristijan TomljanovićKristijan Tomljanović
Kristijan Tomljanović
MFMilivoj Franjević
Milivoj Franjević
Ivan BalenovićIvan Balenović
Ivan Balenović
DUDamir Ugarković
Damir Ugarković
IMIva Matak
Iva Matak
AKAntonija Kolar
Antonija Kolar
In the last couple of years, there have been a great number of articles that cover and emphasize the advantages and possibilities that UAS (Unmanned Air System) offers in forest ecosystem research. In the available research, alongside UAS, the importance of developing sensors that are designed to be used with UAV (Unamnned Air Vehicle), a flight programming software and UAS collected data processing software have been pointed out. With the widespread use of high-precision sensors and accompanying software in forestry, it is possible to obtain accurate data in a short time that replaces long-term manpower in the field with equal or in some cases, such as windthrow calculation or wildlife counting, greater accuracy. The former practice of manual imagery processing is being partly replaced with automated approaches. The paper analyses studies that deal with some form of application of UAS in forestry, e.g. forest inventory, forest operations, ecological monitoring, forest pests and forest fires, and wildlife monitoring. In the forest inventory, a large number of studies deal with the possibilities of applying UAS in mapping vegetation and individual trees, morphological research of individual parts of trees, surface analysis, etc. The use of remote and proximal sensing technologies in forest engineering has mainly been focused on defining surface roughness and topology, road geometry, planning and maintenance, ground-based and cable-based harvesting and soil characteristics and displacement. Wildfire monitoring already relies heavily on the use of UAS and thermal cameras in operations, and it is similar to the mapping of windthrow or directions of the spread of certain insects important for forestry. In wildlife research, numerous studies deal with abundance research of individual terrestrial birds and mammals using UAS thermal imagery. With some drawbacks such as wildlife disturbance or limited UAV range, common to most of the processed studies are positive attitudes regarding the application of UAS in forestry sensing and monitoring, which is slowly becoming a common operative practice, with the scientists’ focus being on developing automated approaches in UAS imagery processing. Reducing the error by improving the technological characteristics of the sensors will in the long run reduce the number of people required to collect data important for forestry, reduce risks and in some cases increase accuracy.

28 November 2025 in Current Forestry Reports
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Journal Article
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Andreja ĐukaAndreja Đuka
Andreja Đuka
Ivica PapaIvica Papa
Ivica Papa
Andrea Rosario ProtoAndrea Rosario Proto
Andrea Rosario Proto
Francesco LatteriniFrancesco Latterini
Francesco Latterini
Piotr S. MederskiPiotr S. Mederski
Piotr S. Mederski
Rodolfo PicchioRodolfo Picchio
Rodolfo Picchio
Purpose of the Review: Forest accessibility and road network density are important concerns not only for forest managers, but also for everyone who benefits from forests, whether for professional or personal use. A well-planned forest road network, integrated with the forest ecosystem, is a fundamental element of rational and efficient forest management. This review aims to describe the current state of forest road density and overall forest accessibility in Europe, as well as relevant global examples. Recent Findings: When a forest road network is distributed adequately across an area, it can support many, if not all, tasks outlined in forest management plans, with high efficiency and minimal costs during construction and maintenance. Collecting data on forest accessibility and primary forest road density at the national level in many countries is a complex task. Diverse terrain conditions, economic factors, and forest management practices have led to variability in the data. A common thread, however, is the optimistic outlook on the use of modern technologies for road network planning and data acquisition. Summary: Efficient forest management, especially harvesting operations, relies on a road network with appropriate density, load-bearing capacity, and alignment. Primary forest transport infrastructure helps reduce timber extraction costs by minimising extraction distances and shortening the travel time from the forest stand to the market. As such, forest road density and accessibility are crucial elements in planning forest operations. Despite differences in terrain conditions, harvesting systems, and economic contexts across Europe and globally, research consistently highlights the need to improve the efficiency of road network planning. Future research on forest accessibility should focus on integrating valuable data collection with scientific research and ensuring effective knowledge transfer to forest practitioners.

10 November 2021 in Croatian journal of forest engineering
Verified
Journal Article
Open access
MRMartyna Rosińska
Martyna Rosińska
Mariusz BembenekMariusz Bembenek
Mariusz Bembenek
Rodolfo PicchioRodolfo Picchio
Rodolfo Picchio
ZKZbigniew Karazzewski
Zbigniew Karazzewski
Andreja ĐukaAndreja Đuka
Andreja Đuka
Piotr S. MederskiPiotr S. Mederski
Piotr S. Mederski