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Large-scale forest resource mapping with spatial gaps in the training data: Comparison of different modeling approaches

Balazs, Andras; Miettinen, Jukka; Nilsson, Mats; Breidenbach, Johannes; Pitkänen, Timo P.; Myllymäki, Mari
International journal of applied earth observation and geoinformation (Elsevier, 2026)

Forest attribute maps are essential for supporting local decision-making regarding forest resource use. Such maps are produced by combining remote sensing and field data through various modeling approaches. When mapping across large areas, spatial gaps in field data used for model training are common. Our study evaluates the performance of three methods—k-Nearest Neighbor (k-NN), Random Forests (RF), and Multi-Layer Perceptron (MLP)—for forest resource mapping across Norway, Sweden, and Finland in an experimental setup with respect to availability of field data around the target area. Models were trained with sample plot sizes (N) ranging from 100 to 3000. RF consistently produced the most accurate predictions in terms of relative bias and RMSE. While spatial gaps in the training data (radius: 7–141 km) affected %RMSE of broad-leaved above ground biomass (AGB), they had minimal impact on %RMSE of both local and country-level predictions of total AGB and volume. For RF with N=3000, %RMSE of total AGB ranged between 53%–55% in Finland and Sweden, and 70%–72% in Norway across gap sizes. However, %bias increased for local predictions across the whole study region with larger gaps: RF with N=500 showed bias of −12%–12% (7 km gap) and −17%–28% (78 km gap). Similarly, country-level %bias of total AGB for Norway increased from −1.7% to −3.7% with larger gaps. In conclusion, spatial gaps in training data can significantly affect bias in predictions. Therefore, forest attribute maps should always be accompanied by metadata describing the training data used.

States of development and application of genetic and genomic tools in aquaculture and conservation programs: a guide for strengthening dialogue among practitioners of aquaculture and genetics

Purcell, Catherine M.; Wringe, Brendan F.; Boudry, Pierre; Brieuc, Marine S.O.; Coulson, Mark W.; Kess, Tony; Solberg, Monica F.; Vehviläinen, Harri; Calboli, Federico C. F.
Aquatic living resources (EDP Sciences, 2025)

Throughout all stages of fish conservation and aquaculture development, genetic and genomic approaches can be leveraged to enhance understanding of the diversity and complexity of these organisms, including the linkage between phenotype and genotype, and their adaptive and breeding potential. These approaches can inform processes ranging from the initial collection of wild broodstock to the ongoing use of genomic selection on domesticated lines. Due to the diversity in cultured fish species, small and medium enterprises (SMEs) commonly explore new species for culture, or work with species within a narrow regional conservation or commercial focus. These enterprises face obstacles in utilising genetic and genomic approaches due to development and implementation costs, specialised skill set requirements, and infrastructure and labour limitations; yet the benefits often outweigh these challenges. Choosing the best molecular genetic or genomic tools depends on programme goals and species, but small and medium enterprises may miss opportunities to acquire more information through their current approaches, or not realise what may be gained through modest investments in genomic tools. To provide better insight and promote discussion and collaboration between culturists and genomic practitioners, we define and describe five States of development and application of genetic and genomic tools frequently observed in aquaculture and conservation breeding programs. We characterise these tools, their general applications, and how current technologies allow programs to advance to higher States without following a sequential progression, a concept we refer to as “State skipping”. This document outlines the available molecular genetic and genomic tools, but does not cover animal breeding or the science behind it. Similarly, bioeconomic models are not included, although relative economic costs and benefits are highlighted. The technical considerations and limitations of various approaches are reviewed, along with available resources for those seeking further support in exploring genetic and genomic tools in breeding programmes.

First European Interlaboratory Ring Test Study to Detect DNA of Crayfish and the Crayfish Plague Pathogen From Water Samples

Bohman, Patrik; Andersson, Kristofer; Strand, David A.; Baudry, Thomas; Theissinger, Kathrin; Maguire, Ivana; Aluma, Michael; Aspán, Anna; Bláha, Martin; Bostjancic, Ljudevit Luka; Delaunay, Carine; Diéguez‐Uribeondo, Javier; Edsman, Lennart; Ercoli, Fabio; Georges, Jean‐Yves; Grandjean, Frédéric; Griffin, Bogna; Iso‐Touru, Terhi; Jacobsson, Birgitta; Kaldre, Katrin; King, Alex; Kozák, Pavel; Markulin, Lucija; Martínez‐Ríos, María; Martín‐Torrijos, Laura; Mohammad, Saima; Mojžišová, Michaela; Muha, Teja Petra; Orsén, Ludvig; Persson, John; Pisano, Simone Roberto Rolando; Pukk, Lilian; Rogell, Björn; Ruokonen, Timo J.; Schmidt‐Posthaus, Heike; Steiner, Jonas; Söderberg, Linda; Vasemägi, Anti; Zenker, Armin; Petrusek, Adam
Environmental DNA : 1 (John Wiley & Sons, 2026)

In recent years, European countries have intensified efforts to control or limit the spread of invasive freshwater crayfish and the crayfish plague pathogen Aphanomyces astaci, while working to conserve native species such as the noble crayfish (Astacus astacus). Although crayfish shed relatively low amounts of DNA into their environment, environmental DNA (eDNA) approaches have proven effective for detecting their presence. A range of protocols and equipment is currently used in eDNA-based monitoring of freshwater crayfish. To evaluate how methodological variation influences detection accuracy, we conducted the first European interlaboratory ring test using eDNA to detect A. astacus, the invasive signal crayfish Pacifastacus leniusculus, a chronic carrier of A. astaci, and the pathogen itself. The aim is to harmonize monitoring methods for crayfish and disease surveillance across laboratories. Eleven teams from thirteen European countries participated, each using its own equipment and protocols to collect and filter water from indoor tanks and outdoor ponds where the presence of A. astacus and P. leniusculus had been experimentally manipulated, as well as from a natural lake containing a P. leniusculus population. The resulting samples were analyzed in each team's laboratory. Despite methodological differences, all teams successfully detected DNA from both crayfish species in indoor tanks (3–10 crayfish/m3). However, detection accuracy declined in outdoor ponds where crayfish density was an order of magnitude lower (0.32 crayfish/m3). Detection was most variable for A. astaci, likely due to its very low prevalence in the host stock. Our study demonstrates the challenges of achieving consistent eDNA results across laboratories and highlights the importance of interlaboratory comparisons. It also underscores the need to identify sources of variability and error, an essential step toward developing robust and standardized protocols. This multinational intercalibration and exchange of knowledge improved methodology and enhanced reliability in crayfish detection.

Analysis of elastic and plastic behaviour in untreated pine wood under scratch test loads combining X-ray computed tomography and finite element simulations

Ronkainen, Helena; Harjupatana, Tero; Miettinen, Arttu; Balobanov, Viacheslav; Venäläinen, Martti; Harju, Anni; Möttönen, Veikko; Fortino, Stefania
Journal of materials science (Springer Nature, 2026)

Wood is an anisotropic material, which affects its performance under different loading conditions. To understand the origin of surface failures occurring in wood under mechanical disintegration loads, an accurate investigation of its elastic and plastic behaviour is required. This study introduces a methodology that integrates experimental scratch testing, X-ray micro-computed tomography (µCT), and finite element simulations to examine the elastic and plastic deformation and failure behaviour of untreated pine wood under scratch loading. In the existing literature, scratch testing is primarily employed to assess coating adhesion or material abrasion resistance; its use for probing the mechanical response of wood remains limited. In the present study, scratches were applied to pine specimens in the radial, tangential, and longitudinal directions of wood using a diamond indenter under constant normal loads perpendicular to the scratched surface. The permanent residual depths measured by (µCT) were compared with FE-predicted deformations. The selected methodology enables quantification of the relationship between wood structure, loading conditions, and scratch performance. The results demonstrated that the regions with higher density favoured elastic deformation, whereas the residual scratch depth, reflecting plastic deformation, provided a reliable indicator of scratch resistance, exhibiting higher scratch resistance for the higher density wood. In particular, the wood with higher density showed residual depths in the range of 53–144 µm in radial direction scratches, whereas the less dense wood showed values between 90 and 300 µm. (µCT) imaging also revealed detailed deformation mechanisms and fracture pathways that develop under scratch-type loading. By coupling (µCT) with FE modelling for wood scratch mechanics, the work deepens the understanding of how wood microstructure responds to different scratch loading conditions. The findings can serve as a scientific reference for future experimental and numerical investigations of scratching, cutting and other disintegration loads in untreated wood and wood-based composites at the microscale.

Local atomic structure of amorphous Fe81−xCoxNb7B12 alloys using synchrotron radiation x-ray diffraction and pair-distribution function analysis

Pussi, Katariina; Gupta, P.; Barbiellini, Bernardo; Srihari, V.; Svec, P.; Bansil, A.; Gupta, A.; Kamali, S.
Applied Physics Letters : 1 (AIP Publishing, 2025)