بررسی اثرات گونۀ علف مار بر خصوصیات خاک مناطق بیابانی (مطالعۀ موردی: منطقۀ عین‌خوش، دهلران)

در مطالعۀ حاضر، برای بررسیcapparis spinosa بر خصوصیات خاک، ابتدا نقشۀ پراکنش گونه‌ها با استفاده از مشاهدات مزرعه و ترانسکت خطی برای محاسبۀ درصد پوشش در فصل رشد ساخته شده است. سپس سایر خصوصیات گیاهی شامل درصد تاج‌پوشش، درصد حفاظت خاک و سایر فاکتورها با استفاده از 69 بوته مورد مطالعه به‌صورت تصادفی محاسبه شد. در ادامه اقدام به حفر پروفیل و نمونه‌برداری از خاک پای بوته‌های موجود (نزدیک ساقه) و محل‌های شاهد (فاقد بوته) با انتخاب 5 تکرار، در مجموع 15 نقطه و از 2 لایه (لایه‌های سطحی و زیرسطحی) گردید و نمونه‌ها به آزمایشگاه منتقل شدند. در آزمایشگاه، عوامل شیمیایی شامل n، k، p، oc، esp، cec، ca، mg، caso4، caco3، cl، hco3، ph،ec و sar اندازه‌گیری شدند. بررسی مقادیر پارامترهای شیمیایی در اندام‌های زیرزمینی بوته نشان می‌دهد که برای هر هفت عامل (n، c، p، k، na، ca، c / n) بیشتر مربوط به خاک زیر بوته‌هاست. از طرف دیگر، برای هفت پارامتر (oc، esp، ca، na، ec، ph، sar) اختلاف آماری بین واحد اراضی (مناطق شاهد، بوتۀ نبکا و بوتۀ طبیعی) و عمق وجود داشت. در کاربری اراضی ec و ph و برای عمق کلسیم، oc و cl در سطح 5% اختلاف داشتند. از نظر عوامل فیزیکی خاک، رطوبت واقعی خاک و رطوبت خاک اشباع شده رابطۀ عمیقی با عمق نشان می‌دهد و در مقایسه با مناطق شاهد (فاقد بوته)، افزایش یافته که این افزایش در لایۀ عمقی بیشتر مشاهده شده و برای سایر پارامترها ارتباط معنی‌دار نبوده است. همچنین نتایج نشان داد که وجود بوته‌های مورد مطالعه باعث کاهش شوری و افزایش قلیائیت خاک می‌شود. تغییرات مادۀ آلی در لایه‌های عمقی نقاط شاهد در لایۀ سطحی زیر بوته‌ها دارای بیشترین مقدار بوده و نشانگر این است که گونۀ فوق مقادیر کربن آلی در خاک زیر خود را نسبت به نواحی اطراف افزایش داده است. نتایج همچنین افزایش oc، na، cl و hco3 را در خاک‌های زیر بوته نشان می‌د‌هد.

Investigating the Effects of Capparis spinosa on Desert Areas’ Soil Characteristics: A Case study of Eyne-Khosh, Dehloran

Introduction: The complex relationship between soil and vegetation is difficult to be simulated by mathematic and statistical models. Since soil, vegetation, and atmosphere are interrelated, they cannot be separately compared. As an important basic factor with regard to soil, vegetation greatly affects ecosystems, especially in arid and semiarid areas. Therefore, the restoration and recreation of this complex phenomenon is much more difficult in arid and desert regions. On the hand, considering the fact that plants generally affect the soil both physically and chemically, it is necessary to know how these parameters interact, the knowledge of which could significantly help restore the vegetation. As a natural, resistant and desertfriendly plant, Capparis spinosa has been known as a multipurpose species in recent years. Because of its deep roots, this species is resistant to wing and its wide canopy can cover a wide range of the soil rsquo;s surface and stabilize sand hills. Therefore, it could be an appropriate choice for preserving soil and water, and antidesertification programs. It could also help control dust storms in different regions. This study, therefore, sought to investigate the effects Capparis spinose on soil characteristics of the EyneKhosh desert area in Dehloran, southern Ilam province, offering it to the relevant officials and decision makers as an effective plant for antidesertification programs. Materials and methods: As a part of desert areas in southwest Iran, the study area is located in Dehloran city, Ilam province. To investigate the effects of Capparis spinosa on soil characteristics, this field study used satellite images, GIS, laboratory analysis, and the date obtained from a statistical software. To this end, first the species rsquo; distribution map was prepared, using field observation and liner transect for calculation of coverage percentage in the growing season. Then, other characteristics including canopy percentage, soil preservation percentage, and other factors were measures, using sixtynine species randomly selected for the study. As for investigating the effects of Capparis spinosa on soil rsquo;s physical and chemical characteristics, a soil profile was dug, and the intended samples were collected from two layers (surface and subsurface) of fifteen points including the surface soil of the existing bushes (near the stem) and control areas (bushless), which were then moved to the laboratory (totally 30 samples) where chemical factors including N, K, P, OC, ESP, CEC, Ca, Mg, Caso4, Caco3, Cl, HCO3, pH, EC, and SAR were measured. Results: The study rsquo;s findings showed that the highest values of all chemical factors (N, C, P, K, Na, Ca, C/N) belonged to the bushes rsquo; subsurface soil. On the other hand, there were statistical differences between land use (control areas, Nebka bushes, and natural bushes) and land depth for other seven parameters (OC, ESP, Ca, Na, EC, pH, SAR). There were 5% difference between EC and PH in terms of land use, and 5% difference between CA, OC, and CI in terms of land depth. For physical soil factors, actual soil moisture and saturated soil moisture show a strong relationship to depth and they are more in both depth, comparing to control part, although for the other parameters (clay, silt, sand, field capacity and wilting point) there were not statistical different. It was also found that the presence of the study bushes decreased salinity and increased alkalinity of the soil. Moreover, the highest number of variations of the organic matters of the control points rsquo; deep layers occurred in subsurface layer of underbushes, indicating that this species had increased the organic carbon of its subsoil compare to the surrounding areas. The findings also showed an increase of OC, Na, Cl, and HCO3 in underbushes soil. Discussion and Conclusion: According to the study rsquo;s results, Capparis spinosa has significant effects on soil characteristics and may change soil texture, increase the soil rsquo;s organic matter, maintain the soil rsquo;s moisture, and in general, preserve the soil and control its erosion. It could also positively affect chemical parameters such as decreasing the salinity, increasing the alkalinity, and increasing OC, Na, Cl, HCO3, and nutrients of the soil. Therefore, this species could be an appropriate choice for antidesertification programs in this region and similar areas.