ترکیبات ساختمانی مادۀ آلی خاک و شناسایی برخی عوامل مؤثر بر آن در مراتع احیاشدۀ دشت قهاوند

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی طبیعت، دانشکده منابع طبیعی و محیط زیست، دانشگاه ملایر

2 گروه مهندسی طبیعت، دانشکده منابع طبیعی و محیط زیست، دانشگاه ملایر، ملایر، ایران

3 گروه علوم و مهندسی شیلات، دانشکده منابع طبیعی و محیط زیست، دانشگاه ملایر، ملایر، ایران.

‎10.22052/deej.2025.256798.1105

چکیده

افزایش ذخیرۀ کربن آلی خاک برای تعدیل تغییرات اقلیمی، اهمیت ویژه‌ای دارد. ‌‌این پژوهش با هدف بررسی تغییرات ذخیرۀ کربن آلی و ارتباط آن با میزان ترکیبات مادۀ آلی خاک (سلولز، همی سلولز و لیگنین) در دو عمق سطحی (۰-۱۰ سانتی‌متر) و زیرسطحی (۱۰-۳۰ سانتی‌متر) در مراتع احیاشدۀ دشت قهاوند در سال 1395 انجام شد. آنالیزهای آماری داده‌های حاصل با استفاده از آزمون نرمالیتی Kolomogrov-Smirnov بررسی گردید و سپس از رویۀ Proc ttest برای بررسی تغییرات معنی‌دار میزان کربن آلی و سایر خصوصیات خاک سطحی و زیرسطحی استفاده شد. نتایج حاصل از این مطالعه نشان داد که تغییرات عمق بر پارامترهای فیزیکی و شیمیایی اندازه‌گیری‌شده، تأثیرات معنی‌داری داشته است وافزایش معنی‌دار مادۀ آلی، سلولز و همی‌سلولز در خاک زیر سطحی به‌ترتیب معادل 2/3، 02/5 و 6/2 برابر مشاهده شد. افزون‌ بر این، بین مادۀ آلی خاک و برخی ویژگی‌های فیزیکوشیمیایی اسیدیته، هدایت الکتریکی و درصد رس و سیلت همبستگی مثبت مشاهده شد. این یافته‌ها بیانگر آن است که احیای پوشش گیاهی و مدیریت قرق، با بهبود ورودی بقایای گیاهی و تثبیت ترکیبات سلولزی، می‌تواند به افزایش پایداری کربن آلی و بهبود کیفیت خاک در اکوسیستم‌های نیمه‌خشک منجر شود.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Assessing Soil Organic Matter Composition and Key Influencing Factors in a Reclaimed Rangeland, Ghahavand Plain

نویسندگان [English]

  • Maryam Hamidi 1
  • Behnaz Attaeian 2
  • Lima Tayebi 3
1 Department of Natural Engineering, Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran
2 Department of Natural Engineering, Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran
3 Department of Fisheries Science, Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran.
چکیده [English]

Introduction: Increasing the soil organic carbon (SOC) stock is critically important for mitigating climate change. Soil carbon sequestration is governed by complex interactions between the atmosphere, soil properties, tree species, the chemical composition of litter, and environmental management. Management practices, particularly grazing and enclosure, can significantly alter the chemical composition of SOC. For instance, grazing pressure has been shown to increase the proportion of more readily degradable carbon compounds, such as cellulose. Despite the recognized significance of carbon sequestration in rangeland ecosystems, the chemical composition of soil organic matter (SOM) and its relationship with soil physicochemical properties remain poorly studied.
The rangelands in the Qahavand Plain have experienced severe degradation due to unsustainable exploitation and overgrazing. Compounding this issue, recurrent droughts have accelerated soil erosion and desertification in the region. In response, restoration initiatives were implemented in degraded rangelands using the species Atriplex canenses and Nitraria schoberi, followed by enclosure management.
 
Materials and Methods: This study was conducted to investigate changes in organic carbon storage and its relationship with soil organic matter components—specifically cellulose, hemicellulose, and lignin—in the surface and subsurface soils of the restored rangelands in the Qahavand Plain. Sampling was carried out in 2016.
A total of 60 soil samples were collected systematically and randomly from two depth intervals: 0-10 cm (surface soil) and 10-30 cm (sub-soil). Various physicochemical properties of these samples were measured.
Prior to statistical analysis, the data were tested for normality using the Kolmogorov-Smirnov test. Variables that violated the assumption of normality were normalized using appropriate transformations: inversion for cellulose, cosine for clay and lignin, and square root for silt and hemicellulose percentages.
Subsequently, a t-test (Proc ttest procedure in SAS v.9.4) was employed to identify significant differences in organic carbon content and other soil properties between the surface and sub-soil layers. Finally, correlation analysis and Principal Component Analysis (PCA) were performed using R and Brodgar software to examine the relationships between organic matter compounds and stored organic carbon.
 
Results and Discussion: The results demonstrated that soil depth had a significant effect on all measured physical and chemical parameters. Notably, the concentrations of organic matter, cellulose, and lignin were significantly higher in the subsurface soil (10-30 cm) compared to the surface layer (0-10 cm), with increases of 34.75%, 79.12%, and 67.57%, respectively.
Several parameters, including pH, electrical conductivity (EC), bulk density, cellulose, hemicellulose, and lignin, were strongly correlated with soil organic matter (SOM) across both depths. Among these, lignin exhibited the strongest positive correlation (r = 0.84), followed by pH (r = 0.78), hemicellulose (r = 0.72), and cellulose (r = 0.71).
The 34.75% increase in the average SOM content in the subsurface soil represents a significant change, underscoring the positive impact of vegetation restoration. This accumulation is likely driven by increased aerial biomass and litter input from the established Atriplex canenses and Nitraria schoberi, a finding that supports our initial hypothesis.
The significant relationships observed between SOM and the physicochemical parameters reinforce the central role of organic matter in soil ecosystems. SOM serves as the primary source of carbon and energy for decomposer and heterotrophic microorganisms. Consequently, any reduction in organic matter input can disrupt microbial activity and impede the decomposition process, creating a feedback loop that further limits soil organic carbon sequestration.
 
Conclusions: In conclusion, this study demonstrates that rangeland rehabilitation in the Qahavand Plain plays a crucial role in enhancing soil organic carbon (SOC) stability and mitigating desertification. The observed relationships between organic matter composition and soil properties, particularly the significant accumulation of the more recalcitrant lignin fraction in the subsurface soil, support this finding. The decomposition process of plant litter typically occurs in two stages: an initial, rapid phase where soluble compounds like cellulose and hemicellulose are broken down, followed by a slower phase governed by the decay of lignin and nitrogen mineralization. Our results, showing a strong correlation between lignin and stable SOC, align with this model and confirm the success of the restoration efforts in building a more stable carbon pool.
Given the context of ongoing climate change, it is recommended that the effects of vegetation restoration on SOC storage be further investigated across other rangeland and forest ecosystems. Furthermore, to enhance carbon sequestration potential and ecosystem resilience in degraded areas like the Qahavand Plain, future restoration programs should consider incorporating alternative native species alongside Atriplex.

کلیدواژه‌ها [English]

  • Soil Organic Matter
  • Carbon Sequestration
  • SOC Stability
  • Soil Quality
  • Desertification

مراجع

  1. Adamczyk, B., Heinonsalo, J., & Simon, J. (2020). Mechanisms of carbon sequestration in highly organic ecosystems – importance of chemical ecology. ChemistryOpen, 9(4), 464–469. https://doi.org/10.1002/open.202000015
  2. Ahmadian, M., Pakparvar, M., & Ashourloo, D. (2010). Evaluation of soil salinity changes using digital processing of Landsat satellite data in the plain (Hamedan Province). Journal of Soil Research (Soil and Water Sciences), 24(2), 179–191. (In Persian).
  3. Amundson, R., & Biardeau, L. (2018). Opinion: Soil carbon sequestration is an elusive climate mitigation tool. Proceedings of the National Academy of Sciences, 115(46), 11652–11656. https://doi.org/10.1073/pnas.1815901115
  4. Béguin, P. (1990). Molecular biology of cellulose degradation. Annual Review of Microbiology, 44, 219–248. https://doi.org/10.1146/annurev.mi.44.100190.001251
  5. Bernoux, M., Carvalho, M. C. S., Volkoff, B., & Cerri, C. C. (2002). Brazil’s soil carbon stocks. Soil Science Society of America Journal, 66(3), 888–896. https://doi.org/10.2136/sssaj2002.8880
  6. Blake, G. R., & Hartge, K. H. (1986). Bulk density. In A. Klute (Ed.), Methods of Soil Analysis. Part I. Physical and Mineralogical Methods (pp. 363–376). Madison, WI: American Society of Agronomy.
  7. Bouyoucos, G. J. (1962). Hydrometer method improved for making particle size analyses of soils. Agronomy Journal, 54(5), 464–465. https://doi.org/10.2134/agronj1962.00021962005400050028x
  8. Brahim, N., Blavet, D., Gallali, T., & Bernoux, M. (2011). Application of structural equation modeling for assessing relationships between organic carbon and soil properties in a semiarid Mediterranean region. International Journal of Environmental Science and Technology, 8(2), 305–320. https://doi.org/10.1007/BF03326218
  9. Cannell, M. G. R. (2003). Carbon sequestration and biomass energy offset: theoretical, potential and achievable capacities globally, in Europe and the UK. Biomass and Bioenergy, 24(2), 97–116. https://doi.org/10.1016/S0961-9534(02)00103-4

10.Ćwieląg-Piasecka, I., Medyńska-Juraszek, A., Winiewska, K., Adamczuk, A., & Słowik, T. (2023). Soil organic matter composition and pH as factors affecting retention of carbaryl, carbofuran and metolachlor in soil. Molecules, 28(14): 5552. https://doi.org/10.3390/molecules28145552

  1. Dias, T., Oakley, S., Alarcon-Gutierrez, E., Ziarelli, F., Trindade, H., Martins-Loução, M. A., Sheppard, L., Ostle, N., & Cruz, C. (2013). N-driven changes in a plant community affect leaf-litter traits and may delay organic matter decomposition in a Mediterranean maquis. Soil Biology and Biochemistry, 58, 163–171. https://doi.org/10.1016/j.soilbio.2012.10.027
  2. Doro, K. O., Stoikopoulos, N. P., Bank, C. G., & Ferris, F. G. (2022). Self-potential time series reveal emergent behavior in soil organic matter dynamics. Scientific Reports, 12(1), 13531. https://doi.org/10.1038/s41598-022-17914-5
  3. Gee, G. W., & Bauder, J. W. (1986). Particle-size analysis. In A. Klute (Ed.), Methods of Soil Analysis. Part I. Physical and Mineralogical Methods (pp. 383–411). Madison, WI: American Society of Agronomy.
  4. GhasemiNejad Raeini, M., & Sadeghi, H. (2017). The evaluation of carbon sequestration at plant’s organs and soil characteristics in understory of Zygophyllum atriplicoides and Gymnocarpus decander (Case study: Saleh-Abad, Hormozgan). Iranian Journal of Rangeland and Desert Research, 24(4), 699–710. (In Persian).
  5. Gilmullina, A., Rumpel, C., Klumpp, K., & Chabbi, A. (2021). Do grassland management practices affect soil lignin chemistry by changing the composition of plant-derived organic matter input? Plant and Soil, 469(1), 443–455. https://doi.org/10.1007/s11104-021-05156-9
  6. Huang, W., Hammel, K. E., Hao, J., Thompson, A., Timokhin, V. I., & Hall, S. J. (2019). Enrichment of lignin-derived carbon in mineral-associated soil organic matter. Environmental Science & Technology, 53(13), 7522–7531. https://doi.org/10.1021/acs.est.9b01724
  7. Huang, Q., Wang, B., Shen, J., Xu, F., Li, N., Jia, P., Jia, Y., An, S., Amoah, I. D., & Huang, Y. (2024). Shifts in C-degradation genes and microbial metabolic activity with vegetation types affected the surface soil organic carbon pool. Soil Biology and Biochemistry, 192, 109371. https://doi.org/10.1016/j.soilbio.2024.109371
  8. Hui, D., Deng, Q., Tian, H., & Luo, Y. (2015). Climate change and carbon sequestration in forest ecosystems. In Handbook of Climate Change Mitigation and Adaptation (pp. 555–594). Springer. https://doi.org/10.1007/978-3-319-14409-2_13
  9. Khayamim, F., & Khademi, H. (2015). Spatial distribution of organic matter in surface soils in three climates of Isfahan province. Journal of Soil Research (Soil and Water Sciences), 29(1), 27–38. (In Persian).
  10. Knorr, W., Prentice, I. C., House, J. I., & Holland, E. A. (2005). Long-term sensitivity of soil carbon turnover to warming. Nature, 433(7023), 298–301. https://doi.org/10.1038/nature03226
  11. Lal, R. (2004). Soil carbon sequestration impacts on global climate change and food security. Science, 304(5677), 1623–1627. https://doi.org/10.1126/science.1097396
  12. Lehmann, J., & Kleber, M. (2015). The contentious nature of soil organic matter. Nature, 528(7580), 60–68. https://doi.org/10.1038/nature16069
  13. Li, L. B., Wang, X. D., Zhang, P., Zhu, Y. Q., Ren, M. Q., & Cai, D. W. (2020). Dynamics of organic matter of soil profiles with different vegetation conditions from the Chinese Loess Plateau: δ13C and δ15N approaches. In IOP Conference Series: Earth and Environmental Science (Vol. 570, No. 2, p. 022008). IOP Publishing. https://doi.org/10.1088/1755-1315/570/2/022008
  14. Mansouri, A., Karimi, A. R., Parvizi, Y., & Emami, H. (2015). Studying the effect of temperature and precipitation on soil organic carbon in part of the rangelands of Kermanshah province. Proceedings of the Second National Conference on Sustainable Agriculture and Natural Resources, Tehran, Iran: Mehr Arvand Higher Education Institute, Environmentalists Extension Group and Iranian Nature Protection Association. (In Persian).
  15. Merriman, L. S., Moore, T. L. C., Wang, J. W., Osmond, D. L., Al-Rubaei, A. M., Smolek, A. P., & Hunt, W. F. (2017). Evaluation of factors affecting soil carbon sequestration services of stormwater wet retention ponds in varying climate zones. Science of the Total Environment, 583, 133–141. https://doi.org/10.1016/j.scitotenv.2017.01.040
  16. Norderhaug, A., Clemmensen, K. E., Kardol, P., & Thorhallsdottir, A. G. (2023). Carbon sequestration potential and the multiple functions of Nordic grasslands. Climatic Change, 176, 55. https://doi.org/10.1007/s10584-023-03537-w
  17. Oji, A., Landi, A., & Hojjati, S. (2018). Carbon sequestration and estimation of its economic value in a part of protected and grazed rangelands of Khuzestan province. Water and Soil, 32(2): 375-386. https://doi.org/20.1001.1.20084757.1397.32.2.11.7. (In Persian)
  18. Paustian, K., Levine, E., Post, W. M., & Ryzhova, I. M. (1997). The use of models to integrate information and understanding of soil C at the regional scale. Geoderma, 79(1–4), 227–260. https://doi.org/10.1016/S0016-7061(97)00043-8
  19. Piccolo, A. (1996). Humus and soil conservation. In Humic substances in terrestrial ecosystems (pp. 225–264). Elsevier.
  20. Raudina, T. V., Smirnov, S. V., & Istigechev, G. I. (2023). Photochemical transformation of dissolved organic matter and behavior of metals in the waters of the southern taiga bog complex, Western Siberia. *Bulletin of the Tomsk Polytechnic University, Geo Assets Engineering, 334(9), 182–193. https://doi.org/10.18799/24131830/2023/9/4115
  21. Razavi, S. A., Kamkar, B., & Sadeghipour, H. R. (2015). Decomposition of five crop residues using four species of soil and woody fungi. Journal of Soil Management and Sustainable Production, 4(4), 331–346. (In Persian).
  22. Saiz, G., Bird, M., Wurster, C., Quesada, C. A., Ascough, P., Domingues, T., Schrodt, F., Schwarz, M., Feldpausch, T. R., Veenendaal, E., & Djagbletey, G. (2015). The influence of C3 and C4 vegetation on soil organic matter dynamics in contrasting semi-natural tropical ecosystems. Biogeosciences, 12(16), 5041–5059. https://doi.org/10.5194/bg-12-5041-2015
  23. Serk, H., Nilsson, M. B., Figueira, J., Krüger, J. P., Leifeld, J., Alewell, C., & Schleucher, J. (2022). Organochemical characterization of peat reveals decomposition of specific hemicellulose structures as the main cause of organic matter loss in the acrotelm. Environmental Science & Technology, 56(23), 17410–17419. https://doi.org/10.1021/acs.est.2c03513
  24. Schmidt, M. W. I., Torn, M. S., Abiven, S., Dittmar, T., Guggenberger, G., Janssens, I. A., & Trumbore, S. E. (2011). Persistence of soil organic matter as an ecosystem property. Nature, 478(7367), 49–56. https://doi.org/10.1038/nature10386
  25. Silva, L. J. R., Souza, T., Laurindo, L. K., Nascimento, G. S., Lucena, E. O., & Freitas, H. (2022). Aboveground biomass, carbon sequestration, and yield of Pyrus pyrifolia under the management of organic residues in the subtropical ecosystem of Southern Brazil. Agronomy, 12(2), 231. https://doi.org/10.3390/agronomy12020231
  26. Six, J., Conant, R. T., Paul, E. A., & Paustian, K. (2002). Stabilization mechanisms of soil organic matter: Implications for C-saturation of soils. Plant and Soil, 241(2), 155–176. https://doi.org/10.1023/A:1016125726789
  27. Srinivasarao, Ch., Venkateswarlu, B., Lal, R., Singh, A. K., Kundu, S., Vittal, D. G., Balaguravaiah, M., Vijaya Sh., B., Ravindra, Ch., Prasadbabu, T., & Yellamanda, R. (2012). Soil carbon sequestration and agronomic productivity of an Alfisol for a groundnut-based system in a semiarid environment in southern India. European Journal of Agronomy, 43, 40–48. https://doi.org/10.1016/j.eja.2012.05.001
  28. Sokol, N. W., & Bradford, M. A. (2019). Microbial formation of stable soil carbon is more efficient from belowground than aboveground input. Nature Geoscience, 12(1), 46–53. https://doi.org/10.1038/s41561-018-0258-6
  29. Schulte, E. E., & Hopkins, B. G. (1996). Estimation of organic matter by weight loss-on-ignition. p. 21–31. In: Magdoff, F. R., et al. (eds.) Soil organic matter: Analysis and interpretation. SSSA Special Publication No. 46. SSSA, Madison, WI.

40.Sheidai Karkaj, E., Sepehri, A., Barani, H., & Mo'tamedi, J. (2017). Relationship of soil organic carbon reserve with some soil properties in East Azerbaijan rangelands. Rangeland, 1)1(2), 125–138. https://doi.org/20.1001.1.20080891.1396.11.2.1.0 (In Persian)

41.Tavallaei, S., Harirchi, Sh., Etemadifar, Z., & Taherzadeh, M. (2022). Lignocellulosic biomass: renewable resources for bioethanol production. Biological Journal of Microorganism, 11(43), 71–95. (In Persian).

  1. Teng, J., Xiang, T., Huang, Z., Wu, J., Jiang, P., Meng, C., Li, Y., & Fuhrmann, J. J. (2015). Spatial distribution and variability of carbon storage in different sympodial bamboo species in China. Journal of Environmental Management, 168, 46–52. https://doi.org/10.1016/j.jenvman.2015.11.034
  2. Thomas, G. W. (1996). Soil pH and soil acidity. In A. Klute (Ed.), Methods of Soil Analysis. Part 3. Chemical Methods (pp. 475–490). Madison, WI: American Society of Agronomy. https://doi.org/10.22108/bjm.2022.131065.1425
  3. Weltzin, J. F., Loik, M. E., Schwinning, S., Williams, D. G., Fay, P. A., Haddad, B. M., Harte, J., Huxman, T. E., Knapp, A. K., Lin, G. H., Pockman, W. T., Shaw, M. R., Small, E. E., Smith, S. D., Tissue, D. T., & Zak, J. C. (2003). Assessing the response of terrestrial ecosystems to potential changes in precipitation. BioScience, 53(10), 941-952. https://doi.org/10.1641/0006- 3568(2003)053[0941:ATROTE]2.0.CO;2
  4. Xie, R., & Wu, X. (2016). Effects of grazing intensity on soil organic carbon of rangelands in Xilin Gol League, Inner Mongolia, China. Journal of Geographical Sciences, 26(11), 1550–1560. https://doi.org/10.1007/s11442-016-1343-7
  5. Yang, Y., Dou, Y., Wang, B., Wang, Y., Liang, C., An, S., & Kuzyakov, Y. (2022). Increasing contribution of microbial residues to soil organic carbon in grassland restoration chronosequence. Soil Biology and Biochemistry, 170, 108688. https://doi.org/10.1016/j.soilbio.2022.10868847.

47.Yimer, F., Ledin, S., & Abdelkadir, A. (2006). Soil organic carbon and total nitrogen stocks as affected by topographic aspect and vegetation in the Bale Mountains, Ethiopia. Geoderma, 1I35(1–2), 335–344. https://doi.org/10.1016/j.geoderma.2006.01.005

 

مهندسی اکوسیستم بیابان
دوره 14، شماره 48
دی 1404
صفحه 57-72

فایل ها

هم رسانی

ارجاع به این مقاله

آمار