Abstract
Wildfire is a major ecological disturbance with profound implications for forest ecosystems, particularly through its effects on soil quality and structure. This study examined the impacts of a severe wildfire (2019) on soil physical, chemical, and micromorphological properties in a mountainous forest region of Yunnan Province, southwestern China. Soil samples were collected from post-fire and adjacent control sites at three depths (0–5, 5–15, and 15–30 cm) and analyzed using a factorial design. Results indicated that the most pronounced fire-induced alterations occurred in the surface layer (0–5 cm). Post-fire soils exhibited increased sand content but reduced clay content, porosity, and field capacity. Chemically, wildfire increased soil pH while reducing electrical conductivity (EC), soil organic carbon (SOC), available phosphorus (AP), and available potassium (AK) in the surface horizon, with limited changes in deeper layers. Micromorphological observations revealed modified aggregate structures, carbonized root fragments, dispersed fungal hyphae, and an abundance of charcoal particles, reflecting both physical and biological disturbances. The soil mass fractal dimension (D) also increased in post-fire soils, indicating greater structural fragmentation and aggregate breakdown. This increase in D is consistent with the observed decreases in porosity and aggregate stability, reflecting a more heterogeneous and degraded pore network. These findings demonstrate that wildfire predominantly affects surface soil horizons, altering infiltration capacity, nutrient dynamics, and microbial activity. Integrating physical, chemical, and micromorphological assessments offers a more comprehensive perspective on fire-induced soil changes, and may provide a useful foundation for post-fire management strategies aimed at supporting the resilience of forest ecosystems under increasing wildfire frequency and intensity.
Data availability
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.
References
Souza-Alonso, P. et al. Fire enhances changes in phosphorus (P) dynamics determining potential post-fire soil recovery in mediterranean woodlands. Sci. Rep. 14, 21718. https://doi.org/10.1038/s41598-024-72361-8 (2024).
García Matallana, R., Lucas-Borja, M. E., Gómez-Sánchez, M. E., Uddin, S. M. M. & Zema, D. A. Post-fire restoration effectiveness using two soil Preparation techniques and different shrubs species in pine forests of South-Eastern Spain. Ecol. Eng. 178, 106579. https://doi.org/10.1016/j.ecoleng.2022.106579 (2022).
Huisman, H., Peeters, H., de Kort, J. W. & Smits, J. Some first observations on ant-nest morphology and micromorphology, the effects of wildfires, and their implications for the Understanding of archaeological features. J. Archaeol. Sci. 170, 106056. https://doi.org/10.1016/j.jas.2024.106056 (2024).
McKenna, P. B. et al. Vegetation recovery of rehabilitated pasture at three coal mine sites following fire disturbance. Ecol. Eng. 209, 107383. https://doi.org/10.1016/j.ecoleng.2024.107383 (2024).
Khosravi Aqdam, K., Rezapour, S., Asadzadeh, F. & Nouri, A. An integrated approach for estimating soil health: incorporating digital elevation models and remote sensing of vegetation. Comput. Electron. Agric. 210, 107922. https://doi.org/10.1016/j.compag.2023.107922 (2023).
Faramarzi, S. E., Pazira, E., Masihabadi, M. H., Torkashvand, M., Motamedvaziri, B. & A. & Modeling and estimating the Spatial distribution of soil organic matter content in irrigated lands. Int. J. Environ. Sci. Technol. 19, 7399–7410. https://doi.org/10.1007/s13762-022-03909-2 (2022).
Siyum, Z. G. Tropical dry forest dynamics in the context of climate change: syntheses of drivers, gaps, and management perspectives. Ecol. Processes. 9, 25. https://doi.org/10.1186/s13717-020-00229-6 (2020).
Keenan, R. J. Climate change impacts and adaptation in forest management: a review. Ann. For. Sci. 72, 145–167. https://doi.org/10.1007/s13595-014-0446-5 (2015).
Marfella, L. et al. Long-term impact of wildfire on soil physical, chemical and biological properties within a pine forest. Eur. J. For. Res. 143, 1379–1399. https://doi.org/10.1007/s10342-024-01696-8 (2024).
Khosravi Aqdam, K., Asadzadeh, F., Rezapour, S. & Nouri, A. Comparative assessment of soil fertility across varying elevations. Environ. Monit. Assess. 195, 1007. https://doi.org/10.1007/s10661-023-11610-1 (2023).
Zhou, G. et al. Fire-driven disruptions of global soil biochemical relationships. Nat. Commun. 16, 1190. https://doi.org/10.1038/s41467-025-56598-z (2025).
Agbeshie, A. A. & Awuah, R. Impact of fire-burn on soil geochemical, microbial biomass and carbon stocks in a dry tropical forest ecosystem. Int. J. Environ. Sci. Technol. 22, 4891–4904. https://doi.org/10.1007/s13762-024-05932-x (2025).
Oliva, M. et al. The complex impacts of fire on soil ecosystems: insights from the 2021 Aspromonte National park wildfire. J. Forestry Res. 36, 68. https://doi.org/10.1007/s11676-025-01864-5 (2025).
Dianati, A., Rasouli-Sadaghiani, M. H., Asadzadeh, F. & Sepehr, E. Khosravi Aqdam, K. A PCA-based standardized spectral index from Sentinel-2 for modeling soil macronutrients in the Miandoab region, Iran. Sci. Rep. 15, 41023. https://doi.org/10.1038/s41598-025-25034-z (2025).
Yang, M. et al. Effect of fire and post-fire management on soil microbial communities in a lower subtropical forest ecosystem after a mountain fire. J. Environ. Manage. 351, 119885. https://doi.org/10.1016/j.jenvman.2023.119885 (2024).
Jia, W., Shu, Y., Zhao, P., Zhou, M. & Yue, Y. Effects of fire intensity on soil microbial diversity and nitrogen cycling functional genes in forests (Northeast China). Frontiers in Microbiology Volume 16– (2025). https://doi.org/10.3389/fmicb.2025.1615520 (2025).
Chebykina, E. & Abakumov, E. In in Advances in Understanding Soil Degradation (eds Saljnikov, E. et al.) 687–700 (Springer International Publishing, 2022). https://doi.org/10.1007/978-3-030-85682-3_31.
Tomé, L. et al. Fuel sources, natural vegetation and subsistence at a high-altitude aboriginal settlement in Tenerife, Canary islands: microcontextual Geoarchaeological data from Roques de García rockshelter. Archaeol. Anthropol. Sci. 14, 195. https://doi.org/10.1007/s12520-022-01661-9 (2022).
Fernández-Martínez, M. & Sánchez-Granero, M. A. Fractal dimension for fractal structures. Topol. Its Appl. 163, 93–111. https://doi.org/10.1016/j.topol.2013.10.010 (2014).
Mataix-Solera, J., Cerdà, A., Arcenegui, V., Jordán, A. & Zavala, L. M. Fire effects on soil aggregation: A review. Earth Sci. Rev. 109, 44–60. https://doi.org/10.1016/j.earscirev.2011.08.002 (2011).
Hueso-González, P., Martínez-Murillo, J. F. & Ruiz-Sinoga, J. D. Prescribed fire impacts on soil properties, overland flow and sediment transport in a mediterranean forest: A 5 year study. Sci. Total Environ. 636, 1480–1489. https://doi.org/10.1016/j.scitotenv.2018.05.004 (2018).
Alogaidi, M. A. H., Asadzadeh, F., Rezapour, S., Khosravi Aqdam, K. & Shabani, F. A quantitative evaluation of landscape patterns’ impact on soil quality: A Regional-Scale case study. Earth Syst. Environ. 9, 1021–1036. https://doi.org/10.1007/s41748-024-00565-z (2025).
Zema, D. A. et al. Predicting the hydrological response of a forest after wildfire and soil treatments using an artificial neural network. Comput. Electron. Agric. 170, 105280. https://doi.org/10.1016/j.compag.2020.105280 (2020).
Ye, P., Zhang, G. & Wu, J. Hotspots and conservation gaps: A case study of key higher plant species from Northwest Yunnan, China. Global Ecol. Conserv. 23, e01005. https://doi.org/10.1016/j.gecco.2020.e01005 (2020).
Yu, H., Wang, L. & Yang, M. Zonal Patterns of Meteorological Drought on the Yunnan-Guizhou Plateau, China. Frontiers in Environmental Science Volume 9– (2021). https://doi.org/10.3389/fenvs.2021.722285 (2021).
Bouyoucos, G. J. Hydrometer method improved for making particle size analyses of soils. Agron. J. 54, 464–465. https://doi.org/10.2134/agronj1962.00021962005400050028x (1962).
USDA-NRCS. Soil survey laboratory methods manual. Soil Surv. investigations report 42 (2004).
Blake, G. & Hartge, K. Bulk density in methods of soil analysis. Methods of soil analysis: Part (1965).
Chapman, H. D. Methods Soil. Anal. Agron. Monogr. 891–901 (1965).
Nelson, D. W. & Sommers, L. E. Methods Soil. Anal. 539–579 (1982).
Bremner, J. M. in Methods of Soil Analysis SSSA Book Series, 1085–1121 (1996).
Olsen, S. R. & Sommers, L. E. Methods Soil. Anal. Agron. Monogr. 403–430 (1982).
Rhoades, J. D. Methods of Soil Analysis. SSSA Book. Ser. 417–435 (1996).
Thomas, G. W. in Methods of soil analysis. SSSA Book. Ser. 475–490 (1996).
Murphy, C. P. Thin section preparation of soils and sediments. (1986).
Bullock, P., Fedoroff, N., Jongerius, A., Stoops, G. & Tursina, T. Handbook for soil thin section description (WolverhamptonWaine Research, 1985).
Glab, T. Application of image analysis for soil macropore characterization according to pore diameter. International agrophysics 21 (2007).
Blazejewski, G. A., Stolt, M. H., Gold, A. J. & Groffman, P. M. Macro- and micromorphology of subsurface carbon in riparian zone soils. Soil Sci. Soc. Am. J. 69, 1320–1329. https://doi.org/10.2136/sssaj2004.0145 (2005).
Su, W. H., Shi, Z., Zhou, R., Zhao, Y. J. & Zhang, G. F. The role of fire in the central Yunnan plateau ecosystem, Southwestern China. For. Ecol. Manag. 356, 22–30. https://doi.org/10.1016/j.foreco.2015.05.015 (2015).
Deng, X. et al. Predicting dynamics of wildfire regimes in Yunnan, China. Discover Appl. Sci. 6, 99. https://doi.org/10.1007/s42452-024-05743-2 (2024).
Fox, D. M., Darboux, F. & Carrega, P. Effects of fire-induced water repellency on soil aggregate stability, Splash erosion, and saturated hydraulic conductivity for different size fractions. Hydrol. Process. 21, 2377–2384. https://doi.org/10.1002/hyp.6758 (2007).
Albalasmeh, A. A., Berli, M., Shafer, D. S. & Ghezzehei, T. A. Degradation of moist soil aggregates by rapid temperature rise under low intensity fire. Plant. Soil. 362, 335–344. https://doi.org/10.1007/s11104-012-1408-z (2013).
Granged, A. J. P., Jordán, A., Zavala, L. M. & Bárcenas, G. Fire-induced changes in soil water repellency increased fingered flow and runoff rates following the 2004 Huelva wildfire. Hydrol. Process. 25, 1614–1629. https://doi.org/10.1002/hyp.7923 (2011).
Stoof, C. R., Moore, D., Ritsema, C. J. & Dekker, L. W. Natural and Fire-Induced soil water repellency in a Portuguese shrubland. Soil Sci. Soc. Am. J. 75, 2283–2295. https://doi.org/10.2136/sssaj2011.0046 (2011).
Cheng, G. et al. Fire differentially affects soil properties of forests and grasslands: A global meta-analysis. CATENA 255, 109031. https://doi.org/10.1016/j.catena.2025.109031 (2025).
Long, Y., Chen, J., Xiao, Y. & Peng, Y. Granular soil particle breakage prediction model based on population evolution theory. Sci. Rep. 15, 13161. https://doi.org/10.1038/s41598-025-92057-x (2025).
Stoops, G. The fabric of soil micromorphological research in the 20th century — A bibliometric analysis. Geoderma 213, 193–202. https://doi.org/10.1016/j.geoderma.2013.08.017 (2014).
Plotnikova, O. O. et al. Micromorphometric parameters of aggregates of uneroded and severely eroded arable chernozems: A case study in Kursk Oblast. Eurasian Soil. Sci. 58, 83. https://doi.org/10.1134/S1064229324604451 (2025).
Yu, K. & DeLaune, R. D. A modified soil diffusion chamber for gas profile analysis. Soil Sci. Soc. Am. J. 70, 1237–1241. https://doi.org/10.2136/sssaj2005.0332N (2006).
Ruth, B., Grundmann, S. & Schroll, R. Simulation of exterior conditions in permanently closed soil chambers by controlling air Flow, soil water Content, and temperature. Water Air Soil Pollut. Focus. 8, 243–250. https://doi.org/10.1007/s11267-007-9162-6 (2008).
Hirmas, D. R., Giménez, D., Subroy, V. & Platt, B. F. Fractal distribution of mass from the millimeter- to decimeter-scale in two soils under native and restored tallgrass prairie. Geoderma 207–208, 121–130. https://doi.org/10.1016/j.geoderma.2013.05.009 (2013).
Wang, Z., Hasi, E., Han, X. & Qingda, M. Fractal characterization of soil particle size distribution under different land use patterns on the North slope of Wula mountain in China. J. Soils Sediments. 24, 1148–1164. https://doi.org/10.1007/s11368-024-03722-z (2024).
Funding
No funding was obtained for this study.
Author information
Authors and Affiliations
Contributions
Yongchao Duan, Conceptualization, Formal analysis, Investigation, data curation, Methodology, Software, writing – original draft, writing – review & editing; Zhibin Liu, Formal analysis, Investigation, data curation, Methodology, Software, writing – review & editing.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Ethics approval
All authors have read, understood, and have complied as applicable with the statement on “Ethical responsibilities of Authors” as found in the Instructions for Authors and are aware that with minor exceptions, no changes can be made to authorship once the paper is submitted.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Reprints and permissions
About this article
Cite this article
Duan, Y., Liu, Z. Wildfire-Induced alterations in soil physical, chemical, and micromorphological properties in forest ecosystems of Yunnan, Southwestern China.
Sci Rep (2025). https://doi.org/10.1038/s41598-025-33913-8
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-025-33913-8
Keywords
- Fractal dimension
- Micromorphology
- Post-fire
- Soil properties
Source: Ecology - nature.com
