High resolution mapping of topsoil properties in the Western Balkans using the LUCAS soil survey
Abstract. The Western Balkans are undergoing rapid socio‑economic and environmental change as national policies converge with those of the European Union (EU). In line with the EU Soil Monitoring Law, a robust, spatially explicit baseline of soil health is required to support both national decision‑making and the region’s EU accession process. This study presents the first EU‑wide comparable, high‑resolution (500 m) digital soil maps for five Western Balkan countries (Albania, Bosnia‑and‑Herzegovina, Montenegro, North Macedonia and Serbia).
A total of 955 field‑sampled points from the Land Use and Cover Area frame Survey (LUCAS) soil campaign were analysed for pH (H₂O and CaCl₂), electrical conductivity, organic carbon, carbonate, phosphorus, total nitrogen, extractable potassium, cation exchange capacity and texture fractions (clay, sand, silt, coarse fragments). Gaussian Process Regression (GPR) was selected because it provides a statistically rigorous framework for (i) integrating the same set of ancillary covariates used in EU‑wide soil mapping, thereby ensuring methodological comparability, and (ii) delivering full predictive‑variance surfaces alongside the mean predictions. Results reveal distinct regional gradients and identify the dominant environmental drivers of soil variability across the Western Balkans.
The generated maps constitute a comprehensive baseline for monitoring soil quality, informing agro‑environmental research, and guiding policy development in the context of EU enlargement.
Competing interests: The authors declare no conflict of interest. They acknowledge that the manuscript was assisted by Genesis (the GPT@JRC evolution) to improve readability and clarity in selected sections. All content was subsequently reviewed, edited, and approved by the authors, who retain full responsibility for the scientific integrity and conclusions of the paper. The core analysis, findings, and arguments remain in the original work of the author(s). The use of this tool did not influence the research findings or their interpretation
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