موسسه تحقیقات خاک و آب مدیریت اراضی 2345-6205 14 1 2026 08 23 A comprehensive review of the effects of biological soil crusts on soil fertility, moisture conservation, erosion control, and ecosystem resilience ارزیابی جامع نقش پوسته‌های زیستی خاک در ارتقای حاصلخیزی، حفظ رطوبت، کاهش فرسایش و تاب‌آوری بوم‌سازگان 113 146 135764 10.22092/lmj.2026.368649.388 FA راشین محمدی دانشجوی دکتری مدیریت مناطق بیابانی، گروه مدیریت مناطق بیابانی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران محسن حسینعلی زاده دانشیار گروه مدیریت مناطق بیابانی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران. Journal Article 2025 05 13 <strong>Objectives</strong> This article presents a comprehensive review of the roles played by biological soil crusts (BSCs) in improving soil fertility, regulating hydrological processes, and reducing soil erosion in arid and semi-arid ecosystems, with special attention paid to application of artificial inoculation approaches. The study addresses a critical environmental challenge in Iran, where arid and semi-arid areas account for approximately 75% of the ecosystems facing such dire consequences as desertification, sand and dust storms, as well as accelerated wind erosion. Due to the moisture deficiency along with other adverse climatic conditions, soils in these ecosystems are highly vulnerable to degradation as a result of their generally sparse vascular plant cover. However, many of these areas are home to intersperse spaces that are covered by communities of plants and microbial microorganisms known as BSCs. These crusts, formed through the interactions of mineral particles with cyanobacteria, algae, fungi, lichens, and bryophytes are recognized as common covers in arid and semi-arid regions. By significantly influencing early ecosystem processes, these crusts are appropriately described as "ecosystem engineers" in arid lands. Numerous field and farm studies have been recently conducted in Iran to investigate the roles of BSCs in improving soil physicochemical properties, regulating hydrological responses, and reducing erosion. <strong>Methodology</strong> A systematic review was conducted using study reports published between 1980 and 2025. The methodology included searching both international databases (using such relevant terms in English as cyanobacteria, algae, fungi, lichens, bryophytes, biological soil crust, soil erosion, runoff, and land restoration) and domestic databases (using equivalent Persian terms). Inclusion criteria involved studies addressing at least one of the following three main themes: 1) erosion and sedimentation, 2) hydrological processes, and 3) fertility and soil quality characteristics, with provision of quantitative or qualitative data. General reports and case studies that merely addressed taxonomic aspects without direct connection to ecosystem functions of crusts were excluded from the present review. Ultimately, approximately 160 sources forming the basis for the current analysis and synthesis were selected that included field and experimental studies, modeling studies, previous reviews, and domestic research. <strong>Results</strong> The comprehensive review of the 160 studies from 1980 to 2025 demonstrates that BSCs significantly reduce soil erosion depending on crust type, successional stage, coverage percentage, and spatial scale. Cyanobacterial crusts seem to have achieved reductions of approximately 77-99% in erosion as reported in many field and laboratory experiments while moss crusts with adequate coverage have reportedly resulted in nearly 100% reduction in surface erosion and, in some cases, dust emission. During early successional stages, cyanobacteria and bacteria are reported to have provided the initial core of surface restoration through extracellular polysaccharides (EPS) generation, nitrogen fixation, soil aggregate formation, and increased structural cohesion. The experimental studies reviewed show that single-application artificial inoculation of these microorganisms in late autumn on loose, erosion-prone soils substantially reduces runoff and sedimentation while it also enables faster formation of stable crusts which reduces ecosystem recovery time from the natural multi-decadal periods to approximately 5-10 years. The implementation cost of this approach is reported to be typically around $350 per hectare, making it a cost-effective strategy for large-scale soil restoration. Upon achieving any coverage greater than 36%, mosses in advanced successional stages become the most effective factor involved in reducing erosion and improving surface stability. By altering the moisture and thermal regimes of the surface layer, they simultaneously affect evaporation, infiltration, and water redistribution on both patch and bulk scales. Lichens also play a role in long-term stabilization under specific conditions (such as rocky or sloped surfaces). These results indicate that the targeted use of artificial BSC inoculation, when combined with moss cover management, represents an efficient and accelerating approach to erosion control, enhanced fertility, and optimized soil hydrological behavior in land restoration programs. Given the moisture-thermal regimes of Iran, the inoculation of such native cyanobacteria as Phormidium spp. and Scytonema spp. at optimal concentrations of 100 million cells per liter (10⁸ cells L⁻¹) during late autumn may be recommended as a practical operational strategy. This approach expectedly strikes a balance among cost, microbial survival, restoration efficiency in arid climates, and ecosystem equilibrium. <strong>Conclusion</strong> The present systematic review of 160 sources demonstrates that biological soil crusts are effective tools for sustainable soil management in arid and semi-arid ecosystems, with their efficacy significantly influenced by the type of constituent microorganisms, successional stage, and environmental conditions. Cyanobacteria, particularly the species Phormidium ambiguum and Scytonema javanicum (used at optimal concentrations of 100 million cells per liter in late autumn), are identified as the most suitable options in arid climates for initial artificial inoculation stages on erosion-prone soils on the grounds that they rapidly stabilize soil particles and enhance fertility through nitrogen fixation and EPS secretion to reduce ecosystem recovery time from several decades to 5-10 years. In contrast, mosses in advanced successional stages, especially with a coverage exceeding 36%, are most effective in reducing erosion (up to nearly 100%) and improving surface stability while they simultaneously moderate soil moisture and temperature regimes to affect runoff, infiltration, and evaporation. Lichens also play a role in long-term stabilization under specific conditions (such as rocky or sloped surfaces). BSCs possess significant operational and economic potentials as demonstrated by scientific evidence for large-scale soil management, particularly through the use of native cyanobacteria inoculation as a low-cost and effective method. The key challenge to be addressed in future is the upscaling of these laboratory findings to the watershed level in which case not only might they be integrated with operational guidelines but also help local communities participate in the continuous monitoring of these living soil health indicators and their adaptation to climate change. Smart integration of microbial inoculation using native plant species along with socio-economic evaluation of technology appraisal by local communities in land restoration programs may be recommended as future research to achieve enhanced ecosystem resilience. <strong>این مقاله مروری با تحلیل پژوهش‌های طی سال‌های ۱۹۸۰ تا ۲۰۲۵، نقش پوسته‌های زیستی خاک (BSCs) را در بهبود حاصلخیزی، تنظیم فرآیندهای هیدرولوژیکی و کاهش فرسایش خاک در بوم‌سازگان‌های خشک و نیمه‌خشک، با تأکید ویژه بر کارآیی رویکردهای تلقیح مصنوعی، بررسی می‌کند. شواهد کمی نشان می‌دهد که BSCs بسته به نوع، مرحله توالی، درصد پوشش و مقیاس مکانی، فرسایش را به‌طور معنی‌داری کاهش می‌دهند؛ به‌گونه‌ای که پوسته‌های سیانوباکتریایی در بسیاری از آزمایش‌های میدانی و آزمایشگاهی، کاهش حدود ۷۷ تا ۹۹ درصدی و پوسته‌های خزه‌ای در پوشش‌های کافی، کاهش نزدیک به ۱۰۰ درصدی در فرسایش سطحی و گاه انتشار غبار را رقم زده‌اند. در مقیاس‌های مختلف، این کارکرد به ریزعارضه‌نگاری، ناهمگنی درون‌جامعه‌ای و الگوی استقرار آن‌ها در مراحل اولیه توالی، سیانوباکتری‌ها و باکتری‌ها از طریق تولید پلی‌ساکاریدهای خارج‌سلولی، تثبیت نیتروژن، تشکیل خاکدانه و افزایش انسجام ساختاری خاک، هسته آغازین فرآیند احیای سطح را فراهم می‌کنند. مرور گستره‌ای از مطالعات تجربی نشان می‌دهد که تلقیح مصنوعی یک‌باره در اواخر پاییز این ریزموجودات بر روی خاک‌های سست و مستعد فرسایش، ضمن کاهش محسوس رواناب و رسوب، تشکیل سریع‌تر پوسته‌های پایدار را ممکن ساخته و زمان بازیابی را از بازه‌های طبیعی چندده‌ساله به حدود ۵ تا ۱۰ سال کاهش می‌دهد؛ این در حالی است که هزینه اجرای این رویکرد معمولاً در حدود ۳۵۰ دلار در هکتار گزارش شده است. در مراحل پیشرفته‌تر توالی، خزه‌ها با دستیابی به پوشش بالاتر از حدود ۳۶ درصد، به مؤثرترین عامل کاهش فرسایش و بهبود پایداری سطحی تبدیل می‌شوند و در عین حال، با تغییر رژیم رطوبتی و دمایی لایه سطحی، بر تبخیر، نفوذپذیری و توزیع مجدد آب در مقیاس لکه‌ای و توده‌ای اثر می‌گذارند. این نتایج نشان می‌دهد که استفاده هدفمند از تلقیح مصنوعی BSCs، در ترکیب با مدیریت پوشش خزه‌ای، رویکردی کارآمد و تسریع‌کننده برای کنترل فرسایش، افزایش حاصلخیزی و بهینه‌سازی رفتار هیدرولوژیکی خاک در برنامه‌های احیای سرزمین محسوب می‌شود. با عنایت به رژیم‌های رطوبتی-حرارتی ایران، تلقیح یک‌باره سیانوباکتری‌های بومی نظیرPhormidium spp.  وScytonema spp.  با غلظت بهینه ۱۰۰ میلیون سلول در لیتر در اواخر پاییز، به‌عنوان راهکار عملیاتی پیشنهاد می‌گردد. این رویکرد، تعادل مناسبی میان هزینه، بقای میکروبی و کارایی احیا در اقلیم‌های خشک و تعادل بوم‌سازگان را برقرار می‌سازد.</strong> https://lmj.areeo.ac.ir/article_135764_0f66c2e6642f32c1a5048da0df7123fb.pdf