دانشگاه محقق اردبیلی مدل سازی و مدیریت آب و خاک 2783-2546 6 1 2026 03 21 The effect of wind erosion on soil physicochemical properties and microbial activity response in the sustainability of the Sistan Plain ecosystem تأثیر فرسایش بادی بر ویژگی‌های فیزیکوشیمیایی خاک و پاسخ فعالیت میکروبی در پایداری اکوسیستم دشت سیستان 149 163 4048 10.22098/mmws.2025.18242.1664 FA مرتضی صابری دانشیار گروه مرتع و آبخیزداری، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران رسول خطیبی استادیار گروه مرتع و آبخیزداری، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران ایران محمدرضا دهمرده قلعه نو دانشیار گروه مرتع و آبخیزداری، دانشکده آب و خاک، دانشگاه زابل، زابل، ایران Journal Article 2025 09 02 Introduction Soil degradation is closely related to increased wind erosion. Wind erosion has multifaceted and widespread effects on arid and semi-arid ecosystems. This phenomenon weakens soil structure and fertility by decreasing the soil's physicochemical quality, reducing organic matter and nutrients, and causing significant biological changes, thereby limiting the ecosystem's capacity. In the Sistan Plain, the occurrence of long and strong winds, known as the 120-day winds, is a prominent example of this erosion that has numerous consequences for the environment and human societies. These winds, by moving soil particles and reducing microbial activity, not only disrupt ecosystem performance but also threaten people's physical health through the spread of polluted dust, leading to increased respiratory problems, allergies, and chronic diseases. Moreover, continuous exposure to these conditions can create psychological and social stress, reduce agricultural productivity and quality of life, and result in economic and migration consequences. These conditions highlight the importance of carefully examining the effects of wind erosion on the physicochemical properties and microbial activities of the soil and its broad implications for ecosystem sustainability and regional challenges. Materials and Methods In the present study, the region was categorized into four levels of soil erosion intensity as the main treatment: no erosion, low, moderate, and severe erosion. To investigate the effects of these treatments on changes in soil properties, sampling was conducted based on a completely randomized design in the fall of 2023. At each erosion level, five homogeneous areas with similar physiographic conditions were selected, and five soil samples were collected from each area at a depth of 0 to 30 cm. The soil samples were combined using a composite sampling method. Some samples were immediately transported to the laboratory in sealed containers and stored in a refrigerator after collection to measure microbial characteristics while maintaining initial humidity. The remaining samples were air-dried and passed through a 2 mm sieve to determine physical and chemical properties. Physical characteristics assessed included soil texture, bulk density, and porosity, chemical characteristics included organic carbon, total nitrogen, available phosphorus and potassium, acidity, electrical conductivity, calcium carbonate, sodium absorption ratio. Microbial characteristics were catalase enzyme activity, basal and stimulated microbial respiration, microbial biomass carbon and nitrogen, and microbial contribution. Data were analyzed using one-way analysis of variance (ANOVA) in SPSS software version 26, and means were compared using Duncan's test at a 95% confidence level. Additionally, correlations among the studied characteristics were examined using R software. Results and Discussion The results of this study demonstrated that the intensity of wind erosion had significant and widespread effects on the physicochemical and microbial properties of the Sistan Plain soil. As erosion intensity increased, the levels of organic carbon, total nitrogen, available phosphorus and potassium, as well as soil porosity, decreased significantly. Conversely, bulk density, electrical conductivity, calcium carbonate, and sodium absorption ratio showed a significant increase. This pattern indicated the removal of fine particles rich in organic matter and nutrients from the soil surface, while coarser particles, richer in calcium carbonate and salts, remained as a result of wind erosion. Changes in surface soil pH were not significant. Additionally, the results indicated a significant decline in microbial activity and soil biological indicators. Catalase enzyme activity, basal and stimulated microbial respiration, microbial biomass carbon and nitrogen, and microbial population all decreased progressively with increasing erosion intensity. The highest values were observed in non-eroded soils, while the lowest values occurred in soils subjected to severe erosion. The ratio of microbial biomass carbon to nitrogen exhibited significant changes but no clear trend. The relative contribution of microbial carbon to total organic carbon increased at high erosion intensities, likely due to a sharp decline in total organic carbon. Correlations between erosion intensity and microbial indices were strongly negative (-0.94 to -0.99), whereas the microbial C/N ratio showed a moderate positive correlation, and the soil microbial contribution exhibited a weak negative correlation. These findings highlight that wind erosion directly limits microbial activity, organic matter decomposition, and soil nutrient cycling, posing a severe threat to the sustainability of soil fertility and ecosystem function in the Sistan Plain. Implementing appropriate soil management practices is essential to reduce erosion, preserve soil microbiota, and ensure ecosystem stability. Conclusion The present study indicates that wind erosion not only alters the physical and chemical properties of the soil but also significantly impacts the activity and dynamics of the microbial community. The reduction of organic matter, changes in bulk density, porosity, nutrient loss, and decreased microbial activity suggest that wind erosion limits the ecosystem's capacity to maintain biological function and sustainability. These findings underscore the importance of soil resource management and the development of conservation strategies in arid regions. They can also inform the design of sustainable agricultural programs aimed at mitigating the adverse effects of wind erosion. Future research should explore the interactions between soil physicochemical and microbial changes over extended time scales, as well as the combined effects of climate change and wind erosion, to develop more effective strategies for protecting dryland ecosystems. فرسایش بادی به‌عنوان یکی از عوامل اصلی تخریب خاک، تأثیر قابل‌توجهی بر فعالیت میکروبی خاک در دشت سیستان دارد. مطالعة حاضر در پاییز ۱۴۰۲ با هدف بررسی اثر شدت فرسایش خاک بر ویژگی‌های فیزیکی، شیمیایی و میکروبی خاک انجام شد. شدت فرسایش در چهار سطح بدون فرسایش، کم، متوسط و شدید دسته‌بندی شد و نمونه‌برداری از عمق صفر تا ۳۰ سانتی‌متری خاک در چهار منطقة همگن با شرایط فیزیوگرافی مشابه انجام شد. نتایج نشان داد که با افزایش شدت فرسایش، کربن آلی از ۵۳/۰ به ۱۴/۰ درصد، نیتروژن کل از ۰۶۱/۰ به ۰۱۲/۰ درصد، پتاسیم قابل جذب از ۶/۱۵۲ به ۵/۶۳ میلی‌گرم در کیلوگرم و فسفر قابل جذب از ۹/۶ به ۵/۱ میلی‌گرم در کیلوگرم کاهش یافت. تخلخل خاک نیز از ۳/۵۵ به ۳۳ درصد افت کرد، در حالی‌که وزن مخصوص ظاهری از ۱۲/۱ به ۵۴/۱ گرم بر سانتی‌متر مکعب، هدایت الکتریکی از ۰۴/۲ به ۶/۸ دسی‌زیمنس بر متر، کربنات کلسیم از ۹ به ۳/۱۹ درصد و شاخص جذب سدیم از ۹/۳ به ۵/۸ افزایش یافتند. تغییر pH خاک معنا‌دار نبود و خاک‌ها ماهیت نسبتاً خنثی خود را حفظ کردند. شاخص‌های میکروبی شامل فعالیت آنزیم کاتالاز، تنفس پایه و برانگیخته، کربن و نیتروژن زیست‌توده میکروبی و جمعیت میکروارگانیسم‌ها با شدت فرسایش کاهش قابل‌توجه داشتند. به‌طوری که کربن زیست‌توده میکروبی ۱۷۹ به ۳/۳۹ میلی‌گرم در کیلوگرم و نیتروژن زیست‌توده از ۶/۱۸ به ۲/۳ میلی‌گرم در کیلوگرم کاهش یافت. نسبت C/N زیست‌تودة میکروبی تغییر معنا‌دار داشت اما روند مشخصی نشان نداد و سهم نسبی میکروبی خاک در شدت‌های بالا افزایش یافت. همبستگی بین فرسایش و شاخص‌های میکروبی منفی و بسیار قوی بود. یافته‌ها نشان می‌دهند که فرسایش بادی توان اکوسیستم را در حفظ عملکرد و پایداری زیستی محدود می‌کند و مدیریت مناسب خاک برای کاهش فرسایش و حفظ میکروبیوتای خاک ضروری است. این مطالعه می‌تواند راهنمای طراحی برنامه‌های پایدار کشاورزی و حفاظت از اکوسیستم‌های خشک باشد.

https://mmws.uma.ac.ir/article_4048_ae9f8ad22a7caf872a754fa098cead44.pdf