Soil quality dynamics across a landslide profile from intact slopes to displaced material and bedrock

Roșian, Gheorghe; Bălc, Ramona; Moga, Roxana; Șfabu, Ștefan; Osiescu, Tudor; Horvath, Csaba; Dicu, Tiberius

doi:10.5194/egusphere-2025-6303

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https://doi.org/10.5194/egusphere-2025-6303

Preprints

12 Jan 2026

| 12 Jan 2026

Soil quality dynamics across a landslide profile from intact slopes to displaced material and bedrock

Gheorghe Roșian, Ramona Bălc, Roxana Moga, Ștefan Șfabu, Tudor Osiescu, Csaba Horvath, and Tiberius Dicu

Abstract. Landslides modify soil systems by disrupting pedogenic processes, altering physical structure, and redistributing chemical constituents. To assess these effects and address key knowledge gaps, this study examines soil quality dynamics along a geomorphological transect crossing intact slopes, displaced landslide material, and parent substrate in the Transylvanian Basin. A suite of physico-chemical, together with magnetic parameters, considered herein as a previously underutilized yet promising proxy for soil degradation, was analysed to identify the soil properties most affected by landsliding, test for statistically significant contrasts between disturbed and undisturbed soils, and determine the most reliable indicators of soil degradation. Magnetic properties showed the clearest diagnostic response: mass-specific and frequency-dependent susceptibility were markedly reduced within the landslide, reflecting the removal or mixing of magnetically enriched horizons. Landslide-affected soils exhibited higher bulk density, lower organic matter, elevated electrical conductivity, and homogenized clay patterns compared with intact profiles. These results demonstrate that landslides profoundly alter soil composition and structure, and highlight magnetic susceptibility, organic matter, and electrical conductivity as robust indicators for assessing disturbance severity. The findings provide a comprehensive framework for evaluating soil degradation in landslide-prone environments.

Received: 17 Dec 2025 – Discussion started: 12 Jan 2026

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Gheorghe Roșian, Ramona Bălc, Roxana Moga, Ștefan Șfabu, Tudor Osiescu, Csaba Horvath, and Tiberius Dicu

Status: final response (author comments only)

RC1:
'Comment on egusphere-2025-6303', Anonymous Referee #1, 08 Feb 2026
General comments
The manuscript presents an interesting characterization of landslide effects on soil properties. The limitations of the study are clearly and appropriately described in the methodology section.
Regarding the methodology, I suggest including data from forested or protected areas as reference sites to compare soil quality against a more stable and well-defined reference condition, or alternatively, using appropriate reference data from the literature.
The statistical analysis is very basic, relying solely on a one-factor ANOVA. Given the limited number of soil properties, applying multivariate analyses such as PCA or clustering may be challenging; however, the authors could explore alternative statistical approaches to strengthen the interpretation of the results.
The discussion section requires revision, as it is currently more theoretical than directly supported by the presented data. For example, in the statement “Bulk density emerged as a particularly robust indicator, with higher values consistently recorded in degraded or landslide-affected areas. High values of bulk density indicate compaction due to mechanical disturbance, sediment displacement, or livestock trampling.”contribution of livestock trampling is introduced without supporting evidence from this study. The authors should clarify whether animal-induced compaction can reasonably be considered comparable to landslide-induced compaction in this context, or restrict the interpretation to processes directly supported by their data.

Specific comments
Figure 1 and Figure 2: The resolution needs to be improved.

Line 135: The geological information is well detailed; however, additional pedological and soil mineralogical information is needed to better understand soil pedogenesis in the region.

Line 160: Please provide references for each method used to determine bulk density.

Line 183: The authors need to be consistent in the use of abbreviations for bulk density (ρ).

Lines 204–211: NDVI is described in the methodology, but the results related to this variable are not presented in the Results section, nor is its specific use sufficiently explained.

Line 206: Present the NDVI formula in the same way as the other formulas included in the manuscript.

Line 235: Add a table clearly indicating the type of sites (reference sites, within landslide, outside landslide).

Line 235: Table 1 should be summarized and complemented with the results of the ANOVA tests.
Citation: https://doi.org/10.5194/egusphere-2025-6303-RC1
- AC1:
  'Reply on RC1', Ramona Bălc, 27 Feb 2026
  
  The comment was uploaded in the form of a supplement.
  
  Citation: https://doi.org/10.5194/egusphere-2025-6303-AC1
  - RC2: 'Reply on AC1', Anonymous Referee #1, 27 Feb 2026
    
    Thank you for taking my comments and suggestions into consideration. However, I do not currently have access to the revised version of the document.
    
    Citation: https://doi.org/10.5194/egusphere-2025-6303-RC2
    
    AC2: 'Reply on RC2', Ramona Bălc, 28 Feb 2026
    
    Thank you very much for your follow-up and for your helpful comments and suggestions. I appreciate your thorough review.
    
    Citation: https://doi.org/10.5194/egusphere-2025-6303-AC2
- AC3: 'Reply on RC1', Ramona Bălc, 09 Jul 2026
  
  Author Response to Referee #1
  General comments
  The manuscript presents an interesting characterization of landslide effects on soil properties.
  RC: The limitations of the study are clearly and appropriately described in the methodology section.
  Regarding the methodology, I suggest including data from forested or protected areas as reference sites to compare soil quality against a more stable and well-defined reference condition, or alternatively, using appropriate reference data from the literature.
  AC: We thank the reviewer for this valuable suggestion. We agree that forested or protected areas can provide a well-defined reference condition for soil quality assessment. However, the present study was specifically designed to evaluate relative soil degradation along a geomorphological transect crossing intact slopes, landslide material, and parent substrate within the same lithological and land-use context, in order to isolate the effects of landsliding. The inclusion of forested or protected reference sites would have introduced additional variability related to vegetation cover and land-use history. To address this limitation, we have clarified in the manuscript that the intact slopes represent a local reference condition, and we addressed this aspect in Section 4.1 by comparing our results with data reported in previous studies from similar areas and for the same soil quality parameters.
  Into the Section 2.2. we added the following sentence (Line 145-148): ‘
  These sites share the same lithology, topographic setting, and land-use history as the landslide-affected soils, allowing the isolation of landslide-induced effects. Although forested or protected areas can represent more stable reference conditions, such sites were not included in the present study to avoid confounding effects related to contrasting vegetation cover and land-use regimes.’ In addition, several changes were applied in Section 4.1 (Line 380-493).
  RC: The statistical analysis is very basic, relying solely on a one-factor ANOVA. Given the limited number of soil properties, applying multivariate analyses such as PCA or clustering may be challenging; however, the authors could explore alternative statistical approaches to strengthen the interpretation of the results.
  AC: Thank you very much for your observations and suggestions. The statistical analysis has been substantially revised and expanded to provide a more robust and comprehensive assessment of soil variability and landslide effects.
  First, given the relatively small sample size and the non-normal distribution of several variables, we replaced the one-factor ANOVA with appropriate nonparametric methods. Specifically, the Mann–Whitney U test was applied to compare soil properties between landslide-affected and unaffected areas, while the Kruskal–Wallis test with Bonferroni-adjusted post hoc comparisons was used to evaluate differences among depth intervals. In addition, comparisons between longitudinal and transversal transects within the landslide area were performed to evaluate lateral variability and internal heterogeneity.
  Second, Spearman rank correlation analysis was introduced to investigate relationships among soil physico-chemical and magnetic properties. This approach provided important insights into the structure of pedogenic relationships and their disruption within the landslide area, thereby strengthening the interpretation of landslide-induced changes.
  Regarding multivariate analyses such as PCA or discriminant analysis, we carefully evaluated their applicability. However, these methods rely on assumptions and sample size requirements that are difficult to satisfy in the present dataset, particularly due to the limited number of independent sampling locations in the reference (unaffected) area and the hierarchical structure of the data (multiple depths sampled within the same points). In particular, discriminant analysis requires multivariate normality and homogeneity of covariance matrices, which could not be reliably ensured. Similarly, PCA is primarily an exploratory dimensionality-reduction technique and does not directly address the study’s primary objective of testing differences between landslide-affected and unaffected soils.
  Therefore, we focused on robust nonparametric univariate and correlation-based analyses that are better suited to the sample size and data structure, while still providing clear and statistically supported evidence of landslide-induced changes in soil properties. These revisions substantially strengthen the statistical rigor and interpretability of the results.
  The revised statistical methods and results are described in detail in the Statistical analysis section (Section 2.3: Line 205-222) and throughout the Results section (Section 3: Line 234-375).
  RC: The discussion section requires revision, as it is currently more theoretical than directly supported by the presented data. For example, in the statement “Bulk density emerged as a particularly robust indicator, with higher values consistently recorded in degraded or landslide-affected areas. High values of bulk density indicate compaction due to mechanical disturbance, sediment displacement, or livestock trampling.” contribution of livestock trampling is introduced without supporting evidence from this study. The authors should clarify whether animal-induced compaction can reasonably be considered comparable to landslide-induced compaction in this context, or restrict the interpretation to processes directly supported by their data.
  AC: We thank the reviewer for this comment. We are agree that the reference to livestock trampling was not directly supported by our analysis and weaken the interpretation. The discussion has been revised to restrict the interpretation of elevated bulk density to geomorphic processes directly evidenced in our study area, namely sediment displacement, topsoil removal, and mechanical compression associated with landslide activity. References to animal-induced compaction have been removed to avoid overinterpretation beyond the scope of the dataset. We replaced the initial discussion with the following one (Section 4.3: Line 529-538): “Bulk density emerged as a particularly robust indicator, with higher values consistently recorded in degraded or landslide-affected areas. In the current study, the higher values of BD could reflect soil compaction and structural disturbance and restructure caused by mass movement processes, includingHigh values of bulk density indicate compaction due to mechanical disturbance, sediment displacement, topsoil removal, and mechanical compression during landslide activity.or livestock trampling, leading to reduced porosity, infiltration capacity, and root penetration These processes determine the reduction in total porosity, water infiltration capacity, and root penetration potential (Hamza and Anderson, 2005; De Rosa et al., 2020). Compaction has been widely recognized as a key physical degradation mechanism that limits soil aeration and water movement, accelerating surface runoff and erosion (Zhang et al., 2006). In addition, the increase in BD is consistent with the observed reduction in organic matter content and the homogenization of clay distribution within landslide-affected profiles, supporting the interpretation of a structurally degraded soil system. Therefore, bulk density can effectively capture the mechanical imprint of both anthropogenic and geomorphic stressors, making it a reliable early-warning indicator in vulnerable landscapes.”
  Specific comments
  RC: Figure 1 and Figure 2: The resolution needs to be improved.
  AC: Thank you for your observation. We replaced the figures with new, improved ones.
  RC: Line 135: The geological information is well detailed; however, additional pedological and soil mineralogical information is needed to better understand soil pedogenesis in the region.
  AC: Thank you for your suggestion. Whitin the subchapter 2.1. (Line 105-112) we inserted the following paragraph: “The pedogenesis process took place on Sarmatian rocks (marls and clays) rich in expandable clay minerals (montmorillonite, illite, beidellite), which, under the conditions of the temperate-continental climate of the Transylvanian Basin, favoured the formation of a Haplic Chernozem (Acree et al., 2020). The soil is poorly debased, saturated in bases (especially Ca²⁺) and characterized by a well-developed mollic horizon. The relatively low permeability of the parent rock determined a moderate alteration of the mineral substrate, with in situ argillization (Acree et al., 2020) and the formation of clay minerals (Ianoș, 2004). The grassy vegetation contributed to the accumulation of organic matter (Blaga et al., 2005), and the thermal and rainfall variations favored the formation and stabilization of humus rich in calcium-saturated humic acids (Pendea et al., 2002), which explains its accumulation in the upper part of the profile and the pedogenetic specificity of the soils in the region.
  RC: Line 160: Please provide references for each method used to determine bulk density.
  AC: The method is already given, as it is described in ISO 11272:2017 – Core Method: …’ where ρb is in g m^-3, md is the mass of the sample dried at 105°C in grams g, and Vs is the volume of the steel cylinder in cubic centimetres cm³ (ISO 11272:2017).’ In addition, we also mentioned this method at Line 192.
  RC: Line 183: The authors need to be consistent in the use of abbreviations for bulk density (ρ).
  AC: Thank you for your comment. We corrected the abbreviations (Line 192)
  RC: Lines 204–211: NDVI is described in the methodology, but the results related to this variable are not presented in the Results section, nor is its specific use sufficiently explained.
  AC: At the beginning of the Results chapter (Line 234-242), we added the following paragraph: ‘The NDVI analysis indicates that vegetation cover within the landslide perimeter is predominantly sparse to moderate, with 93% of pixel values below 0.40. Around 24% of the area falls within the stressed or sparse vegetation class (NDVI 0.11–0.30), while 7% is characterized by nearly bare surfaces (0.00–0.10), indicating an exposed soil and a reduced protective cover. Only 0.3% of the landslide surface is covered by dense vegetation (NDVI > 0.60), and areas potentially associated with stable woody cover remain below 1%. This analysis reflects an unstable terrain characterized by scarce vegetation, with limited root development and reduced soil cohesion. The dominance of low NDVI values indicate that post-failure vegetation recovery is in an early successional stage, reflecting recent or ongoing slope reactivation processes. To support the observations derived from the NDVI analysis, the following section presents the results of the soil physicochemical parameters, which contribute to the detailed characterization of the studied slope.
  RC: Line 206: Present the NDVI formula in the same way as the other formulas included in the manuscript.
  AC: We inserted the formula in the same way as the other formulas were included in the manuscript (Line 226)
  RC: Line 235: Add a table clearly indicating the type of sites (reference sites, within landslide, outside landslide).
  AC: Tables (1 and 3) were added to summarize the soil properties for landslide-affected sites, unaffected reference sites, and parent material samples, including minimum, median, and maximum values for each parameter across the investigated depth intervals. These tables provide a clear overview of the dataset and explicitly distinguish between the different site categories.
  RC: Line 235: Table 1 should be summarized and complemented with the results of the ANOVA tests.
  AC: To improve clarity and readability, statistically significant differences are now directly indicated in the multi-panel boxplot figure (Figure 3) using significance brackets. This graphical representation allows readers to easily identify statistically significant differences both between landslide-affected and unaffected soils at the same depth and between depth intervals within each zone. We believe that presenting statistical significance in graphical form improves interpretability and avoids redundancy with the descriptive statistics provided in the tables.
  The following references were added to the References list:
  Acree, A., Weindorf, D.C., Paulette, L., Van Gestle, N., Chakraborty, S., Man, T., Jordan, C., Prieto, J.L.: Soil classification in Romanian catenas via advanced proximal sensors, Geoderma, 377, 114587, https://doi.org/10.1016/j.geoderma.2020.114587, 2020.
  Blaga, Gh., Filipov, F., Paulette, L., Rusu, I., Udrescu, S., Vasile, D.: Pedology (in Romanian), Editura Mega, Cluj-Napoca, 449 pp., 2008.
  Dearing, J.A.: Environmental magnetic susceptibility using the Bartington MS2 system, Chi Publishing, England, 2nd edition, 52 pp., 1999.
  Ianoş, Gh.: Geography of soils (in Romanian), Editura Mirton, Timişoara, 319 pp., 2004.
  Panagos, P., De Rosa, D., Liakos, L., Labouyrie, M., Borrelli, P., Ballabio, C.: Soil bulk density assessment in Europe, Agriculture, Ecosystems and Environment, 364, 10897, https://doi.org/10.1016/j.agee.2024.108907, 2024.
  Pendea, I.F., Szanto, Zs., Bădărău, Al.S., Dezsi, S.: Age and pedogenic reconstruction of a paleo-relict chernozem soil from Central Transylvanian Basin, Geologica Carpathica, 53, 37-38, 2002.
  The following reference was deleted from the References list:
  Boushane, N. and Bouhlassa, S.: Assessing magnetic susceptibility profiles of topsoils under different occupations, International Journal of Geophysics, 2018, 1-8, https://doi.org/10.1155/2018/9481405, 2018.
  
  Citation: https://doi.org/10.5194/egusphere-2025-6303-AC3
RC3:
'Comment on egusphere-2025-6303', Anonymous Referee #2, 29 Jun 2026
Title: "Soil quality dynamics across a landslide profile from intact slopes to displaced material and bedrock"
General Assessment
The article by Roșian et al. investigates soil quality dynamics across a complete landslide profile in Transylvanian Basin, integrating physical, physio-chemical, and magnetic soil properties. The study compares intact soils, displaced landslide material, and exposed parent material to identify indicators of soil degradation associated with landslide processes,
The manuscript presents a valuable dataset and demonstrates considerable field effort. The integration of multiple soil indicators provides useful information regarding the consequences of mass movement on soil functioning. The paper is generally well structured, and the objectives are clearly stated. The results contribute to the growing body of literature examining how geomorphic disturbances influence soil quality and landscape evolution.
However, several aspects of the manuscript require improvement before publication. In particular, the discussion could better connect the findings to broader pedological and geomorphological theory. Some conclusions appear stronger than the available evidence supports, and additional clarification of methodological decisions would improve reproducibility.
Overall, I believe the manuscript has merit and can become a useful contribution after substantial revision.
Introduction
The introduction provides a comprehensive overview of landslide impacts on soils. However, several sections are descriptive and could be condensed.
L 25 is not a good sentence structure.
Some paragraphs reviewing previous studies are repetitive.
The research gap should be stated more explicitly near the end of the introduction.
The objectives are clearly stated.
The hypothesis should be rewritten in a more formal style.
Methodology
The study area description is adequate. Please provide additional details regarding the following aspects: sampling strategy; criteria used to select sampling points; measures taken to minimize sampling bias and quality assurance procedures for laboratory analyses. These details are important for reproducibility.
The authors acknowledge several limitations, but these deserve a more critical discussion. Important questions could be answered:
Why were only two transects selected?

How representative are they of the entire landslide?

Were sampling locations selected randomly or subjectively?

Could micro-topography influence the observed trends?

Because landslide deposits are highly heterogeneous, spatial variability is a major issue.
Results and Analysis
The results are clearly presented and generally easy to follow. However, several sections repeat information already visible in tables and figures. Consider focusing on the most important trends rather than describing every numerical difference. Greater emphasis should be placed on effect sizes rather than only statistical significance.
Discussion
The discussion should move beyond description and provide more mechanistic explanations. In particular:
What processes explain the observed differences among geomorphic positions?

How does material displacement alter soil-forming factors?

What role do erosion and deposition play in shaping the observed patterns?

Linking the results to established soil formation concepts would substantially strengthen the discussion.
Conclusion
The conclusions are generally supported by the data. However, some statements appear broader than the scope of the study. The conclusions should emphasize that findings are based on a specific landslide system and may not necessarily apply to all environments.
Future research directions should also be suggested.
Technical Comments
Several sentences are unnecessarily long and should be simplified (e.g., L25)

Abbreviations should be defined at first use.

Ensure consistency in units throughout the manuscript.

Verify that all figures are readable when printed at journal scale ( Fig 2)

Table
Table 1 is useful but extremely large. Consider moving complete datasets to supplementary material and presenting summary statistics in the main manuscript.
Language
Overall English is understandable. However, numerous grammatical issues remain. Examples:
L -30 soil quality respond,
L -63 Hypothesized that,
L-64 displace material
L-135 Despite of all these
Professional English editing is recommended before publication.
Citation: https://doi.org/10.5194/egusphere-2025-6303-RC3
- AC4: 'Reply on RC3', Ramona Bălc, 09 Jul 2026
  
  Author Response to Referee #2
  General Assessment
  The article by Roșian et al. investigates soil quality dynamics across a complete landslide profile in Transylvanian Basin, integrating physical, physio-chemical, and magnetic soil properties. The study compares intact soils, displaced landslide material, and exposed parent material to identify indicators of soil degradation associated with landslide processes,
  The manuscript presents a valuable dataset and demonstrates considerable field effort. The integration of multiple soil indicators provides useful information regarding the consequences of mass movement on soil functioning. The paper is generally well structured, and the objectives are clearly stated. The results contribute to the growing body of literature examining how geomorphic disturbances influence soil quality and landscape evolution.
  However, several aspects of the manuscript require improvement before publication. In particular, the discussion could better connect the findings to broader pedological and geomorphological theory. Some conclusions appear stronger than the available evidence supports, and additional clarification of methodological decisions would improve reproducibility.
  Overall, I believe the manuscript has merit and can become a useful contribution after substantial revision.
  Introduction
  RC: The introduction provides a comprehensive overview of landslide impacts on soils. However, several sections are descriptive and could be condensed.
  AR: We thank the reviewer for this valuable suggestion. We modified and condensed some of the paragraphs in this section.
  RC: L 25 is not a good sentence structure.
  AR: We thank the reviewer for pointing this out. We have rewritten the sentence as suggested: "According to Doran and Parkin (1996), soil quality refers to the ability of soil to function properly in a natural and/or managed ecosystem in order to sustain biological productivity, preserve environmental quality, and help in the health of all living organisms. In this regard, soil quality is highly susceptible to geomorphological disturbances, such as mass-wasting, which can significantly affect soil characteristics and ecosystem functioning.
  RC: Some paragraphs reviewing previous studies are repetitive.
  AR: We revised Paragraph 2 and 3 accordingly to improve clarity, logical flow, and reduce repetition.
  RC: The research gap should be stated more explicitly near the end of the introduction.
  AR: We thank the reviewer for this comment. The research gap was already stated at the end of the introduction (paragraph preceding the objectives), but we have revised the opening sentence to state it more explicitly: “Critically, no study has yet examined the entire landslide profile, from intact slope through displaced material to exposed bedrock, as a continuum of soil quality dynamics.”
  RC: The objectives are clearly stated.
  AR: We did not make changes to this section.
  RC: The hypothesis should be rewritten in a more formal style.
  AR: We thank the reviewer for this comment. We have rewritten the hypothesis in a more formal style, splitting it into two explicitly stated predictions and using standard present-tense hypothesis phrasing: “We proposed a scenario in which soil quality decreased along a gradient from the undisturbed slope to the displaced material, and declined further toward the bare rock, reflecting the combined influence of disturbance intensity and pedogenic resetting. The displaced material was anticipated to exhibit an intermediate level of soil quality, attributable to either partial pedogenic recovery or horizon mixing. By using multiple soil quality indicators, the present study seeks to develop an effective framework for differentiating geomorphic zones and for explaining the trends in soil system evolution associated with slope-failure events."
  Methodology
  RC: The study area description is adequate. Please provide additional details regarding the following aspects: sampling strategy; criteria used to select sampling points; measures taken to minimize sampling bias and quality assurance procedures for laboratory analyses. These details are important for reproducibility.
  AR: We thank the reviewer for this observation. In response, we have rewritten section 2.2 with more detailed explanation of the sampling point determination process. In particular, the authors point out that the location of sampling points was fixed at equal distance from one another along transect lines, instead of being chosen arbitrarily. The authors also point out the fact that the spatial distribution of the sampling points does not indicate the lack of regularity or orderliness of their arrangement, since it is due to projection effect and steep slope of the area in question. The process of quality assurance during the data gathering procedure is explained in section 2.2, where the calibration and measuring procedures are described in detail.
  RC: The authors acknowledge several limitations, but these deserve a more critical discussion. Important questions could be answered:
  AR: The concerns raised by the reviewer were discussed in detail in our response but were not included in the manuscript because they were developed to respond to the reviewer's concerns and not relevant to any additional method. However, in case the reviewer feels that these explanations should be added to the manuscript, we will be ready to do so in the revised version.
  RC: Why were only two transects selected?
  AR: Two chosen sampling transects (longitudinal and transverse) were determined mainly by the compact size of the landslide (~3.65 ha) and by field accessibility limits, which included the steepness of the slope and locally unstable conditions near the head scarp and lateral margins. The design of the transects considered both the downslope geomorphological organization of the landslide (longitudinal transect) and the cross-slope variability of the displaced mass (transverse transect).
  RC: How representative are they of the entire landslide?
  AR: The study identified sampling points at the main geomorphological zones of the landslide: on the head scarp, the landslide body, and the toe (Fig. 2C). This sampling strategy covered most of the limited surface area of the landslide. The two transects could not capture the spatial heterogeneity usually associated with landslide terrain; however, the distribution of sampling points across the main geomorphological units provided a representative framework for the present study’s objectives. Using a transect-based sampling design inherently missed fine-scale spatial variability.
  RC: Were sampling locations selected randomly or subjectively?
  AR: Sampling points were distributed equally along each transect. The local distance between sampling points was determined by the slope gradient and field accessibility. The final position of the sampling points did not depend on a completely random sampling system or a random sampling procedure but rather depended on the terrain conditions or a systematic but field-adapted random sampling process.
  RC: Could micro-topography influence the observed trends?
  AR: The region of the landslide that has become unstable shows considerable microtopographic variability, with surface irregularities and small-scale relief typical of new failure material (Fig. 2E-G). These characteristics can lead to increased localized variations in soil attributes that may not be fully accounted for by transect sampling. This constraint is acknowledged and must be considered when interpreting the spatial pattern observed in the landslide mass.
  Results and Analysis
  RC: The results are clearly presented and generally easy to follow. However, several sections repeat information already visible in tables and figures. Consider focusing on the most important trends rather than describing every numerical difference. Greater emphasis should be placed on effect sizes rather than only statistical significance.
  AR: Thank you very much for your observations and suggestions. The Results section has been substantially revised and expanded to provide a more robust and comprehensive assessment of soil variability Discussion
  Discussion
  RC: The discussion should move beyond description and provide more mechanistic explanations.
  In particular:
  What processes explain the observed differences among geomorphic positions?
  How does material displacement alter soil-forming factors?
  What role do erosion and deposition play in shaping the observed patterns?
  Linking the results to established soil formation concepts would substantially strengthen the discussion.
  AR: We thank the reviewer for this valuable suggestion. In response, we added a new subsection to address the reviewer's comments and questions:
  “4.4. Geomorphic controls on post-landslide pedogenesis
  The spatial variability of soil characteristics across the landslide shows that geomorphological processes behave differently on the slope, which significantly influences post-landslide processes. Erosional processes control the detachment and transportation zones, where the vegetation on the upper horizons is stripped off and less weathered material is exposed. When soil is eroded, it leads to the removal of the surface horizons, making it possible for soil formation to restart under the new environmental conditions because of the exposure of the underlying layer of soil, which has undergone less weathering. Specifically, landslide soil has mechanically mixed profiles preventing the successful development of distinct soil horizons. Therefore, erosion and deposition not only redistribute soil material down the slope but also change the direction of soil formation by not allowing for emergence and occurrence of soil horizons.
  In the studied area it appears that landslide soils have considerably higher bulk density and less organic matter compared to non-affected terrains. Likewise, the values of magnetic susceptibility were found to be consistently low and comparable to those observed in the parent material, indicating the possibility of either the removal of any pedogenically enriched surface horizons or mixing it with the freshly exposed parent material, thereby limiting the formation of ferrimagnetic minerals, which are usually associated with soil development.
  In contrast, depositional zones are known for their high textural diversity and lack of vertical stratification. The variability in soil composition is due to the transport and deposition of sediments from different upland sources. The high electrical conductivity of the landslide mass indicates a fresh mineral substrate that has become exposed, leading to the leaching of soluble ions through mass movement. The low NDVI, on the other hand, indicates the decreased amount of plant cover, which suggests that there has been little biological recovery and weakened root support, resulting in lower amounts of organic matter being produced and slow rate of the soil-forming process.
  The findings of this study are in line with the theoretical frameworks of soil-landscape evolution proposed by previous researchers, particularly Minasny et al. (2015), van der Meij (2022), which highlight the interrelationship between geomorphological and soil formation processes. The results also indicate that soil erosion, transportation, and deposition are interrelated processes of soil redistribution. Mechanical mixing of sediments accounts for the observed differences in clay content and the non-existence of clearly defined vertical profiles of soils, as well as the difference in physical, chemical, and magnetic properties of soils formed on the landslide.
  In summary, the geomorphological position controls pedogenetic processes after landslides because it regulates erosion intensity and the processes of material transfer and deposition throughout the slope. These processes affect the development of pedogenetic soil horizons in the area and create a mixture of soil horizons that differ little from each other vertically. Data from bulk density measurements, organic matter content, magnetic properties, electrical conductivity, and vegetation indicate that the materials of the post-landslide soils are in the development phase.
  We also added the new cited material:
  van der Meij, W.M., 2022. Evolutionary pathways in soil-landscape evolution models. Soil, 8, 381-389. https://doi.org/10.5194/soil-8-381-2022
  Minasny, B., Finke, P., Stockmann, U., Vanwalleghem, T., McBratney, A.B., 2015. Resolving the integral connection between pedogenesis and landscape evolution. Earth-Science Reviews, 150, 102-120. http://dx.doi.org/10.1016/j.earscirev.2015.07.004
  Conclusion
  RC: The conclusions are generally supported by the data. However, some statements appear broader than the scope of the study. The conclusions should emphasize that findings are based on a specific landslide system and may not necessarily apply to all environments.
  Future research directions should also be suggested.
  AR: We highly appreciate the reviewer for noting this important point. We have improved the Conclusion section to indicate that our study is limited to one particular landslide system and its characteristics and that more research is required to reach general conclusions about the possible application of our findings to other systems. We have added a paragraph about our future research, including the need for more spatial coverage and conducting comparative studies of different land types (see revised Conclusions in the revised paper).
  Technical Comments
  RC: Several sentences are unnecessarily long and should be simplified (e.g., L25)
  AR: We appreciate the reviewer's comment on this matter and have thoroughly gone through the manuscript to simplify long sentences that have been made unnecessarily lengthy, including the commented sentence (L25) to make it easier and better to read in general.
  RC: Abbreviations should be defined at first use.
  AR: We thank the reviewer for this observation. We have carefully checked the manuscript and ensured that all abbreviations are defined in full at their first occurrence in the text.
  RC: Ensure consistency in units throughout the manuscript.
  AR: We thank the reviewer for this observation. We have carefully reviewed the entire manuscript and revised the text to ensure consistent use of units and formatting throughout.
  RC: Verify that all figures are readable when printed at journal scale ( Fig 2)
  AR: We thank the reviewer for this observation. We have verified that Figure 2 remains fully readable when printed at journal scale; no further adjustments were necessary."
  Table
  RC: Table 1 is useful but extremely large. Consider moving complete datasets to supplementary material and presenting summary statistics in the main manuscript.
  AR: We thank the reviewer for this suggestion. The full dataset as presented in Table 1 has now been replaced by summary statistics tables in the main manuscript which allows us to provide the data in a clearer and more understandable form while preserving the vital information necessary in this study.
  Language
  RC: Overall English is understandable. However, numerous grammatical issues remain.
  Examples:
  L -30 soil quality respond,
  Corrected
  L -63 Hypothesized that,
  The sentence has been rephrased
  L-64 displace material
  The sentence has been rephrased
  L-135 Despite of all these
  Corrected
  RC: Professional English editing is recommended before publication.
  AR: We thank the reviewer for this suggestion. We have carefully revised the manuscript to improve clarity and language throughout, and will continue to refine the English during the proof stage if needed. Sau
  We thank the reviewer for this suggestion. The manuscript has been thoroughly reviewed and edited for English language and style by the author team with attention to grammar, clarity, and scientific phrasing throughout
  
  Citation: https://doi.org/10.5194/egusphere-2025-6303-AC4

Gheorghe Roșian, Ramona Bălc, Roxana Moga, Ștefan Șfabu, Tudor Osiescu, Csaba Horvath, and Tiberius Dicu

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Jan 2026	448	311	50	809
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May 2026	33	48	2	83
Jun 2026	22	9	0	31
Jul 2026	18	24	2	44

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Short summary

This study investigates soil quality along a transect in the Transylvanian Basin, comparing intact slopes, landslide deposits, and parent material, using physico-chemical and magnetic measurements. Overall, the study shows that landslides substantially degrade soil structure and composition and highlights magnetic susceptibility, organic matter, and electrical conductivity as reliable indicators of disturbance severity.


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