بررسی تأثیر پوستههای زیستی خاک در کنترل ریزگردهای حاشیه دریاچه ارومیه با استفاده از تونل باد
First Statement of Responsibility
/ابوالفضل اسماعیل نژاد جراغلی
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
: کشاورزی
Date of Publication, Distribution, etc.
، ۱۳۹۵
NOTES PERTAINING TO PUBLICATION, DISTRIBUTION, ETC.
Text of Note
چاپی
CONTENTS NOTE
Text of Note
Nowadays, drying of the Urmia Lake as a largest saline lake in the world and emerging it's saline bed from water has caused the risk of salty dune storms which threats the health of human society and also plants and animal communities living in the region. Biological soil crusts (BSCs) as a dust stabilizers attracted the attention of Soil conservation experts in recent years. Although, the presence of water by the impenetrable lake bed and endorheic basin can be an advantage to create BSCs, but the extraordinary of the lake bed salinity is a factor for prevention of its establishment in the region. Therefore, the present research work has been carried out to investigate the effects of inoculating the Cyanobacteria, algae and their combination to create BSCs for dust control. In this study, an algae attributed to Chlamydomonas sp, and a cyanobacteria attributed to Anabaena sp isolated from the soils of Urmia Lake margin were used to create BSC in four soil samples which collected from 0-10 cm of the current margin (A), the previous bed (B), affected lands by lake (C) and Quomtappe sand dune (D). The main characteristics of the A, B and C soil samples are their highly salinity (their ECe are 108, 140 and 118 dS/m, respectively) and sodicity. Also, texture class of the soil A was loamy sand and other two soils had clay textures. Soil D was Non-saline, but it was sodic with a sandy texture class. This study was conducted separately in each soil in a completely randomized design under four inoculation treatments of non-inoculated (T0), Algae (T1), cyanobacteria (T2) and equal mixture of algae and cyanobacteria (T3) with three replication. In the experiment, the soil was placed into wind tunnel trays and a suspension containing microorganisms mixed with the trays surface soil. During the experiment, water was sprayed to the trays at the morning and evening of every day. After passing the incubation period (30 days), some characteristics of samples such as pH, EC, cold water extractable carbohydrate (CWEC), hot water extractable carbohydrate (HWEC), sulfuric acid extractable carbohydrate (SAEC), organic matter, crust thickness, penetration resistance, wind erosion threshold velocity and soil loss in the wind tunnel were measured and Correlation between the measured characteristics was obtained through the SPSS software. Analysis of variance and so comparison between the means of treatments were analyzed with MSTATC software. In this research, Chlorophyll an amount, was used as an indicator of the microorganism's population in the samples. Based on obtained results the amount of Chlorophyll a in the T2 treatment of soil A, and all treatments of soil D was significantly increased in comparison to the control and crust thickness showed increase in all treatments by microorganisms inoculation. But effect of the treatments was significant in soils A and D. At all treatments inoculation of microorganisms in soil A caused to increase. 46,. 34 and
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
کارشناسی ارشد
Discipline of degree
علوم خاک
Date of degree
۱۳۹۵/۱۱/۱۸
Body granting the degree
تبریز
SUMMARY OR ABSTRACT
Text of Note
امروزه خشک شدن دریاچه ارومیه به عنوان بزرگترین دریاچه شور دنیا و بیرون آمدن بستر شور آن از زیر آب سبب شده است که خطر تولید ریزگردهای نمکی، سلامتی جامعه بشری و نیز زندگی جامعه گیاهی و جانوری موجود در منطقه را مورد تهدید قرار دهد .پوستههای زیستی به عنوان تثبیت کننده ریزگردها در سالهای اخیر مورد توجه کارشناسان حفاظت خاک قرار گرفتهاند .گرچه وجود آب به علت غیر قابل نفوذ بودن بستر دریاچه و قرار گرفتن در منطقه پست میتواند مزیتی برای ایجاد پوستههای زیستی باشد، اما شوری فوقالعاده زیاد بستر دریاچه عاملی برای جلوگیری از استقرار آن در منطقه است .بنابراین تحقیق حاضر به منظور بررسی تأثیر تلقیح سیانوباکترها، جلبکها و ترکیب آنها در ایجاد پوستههای زیستی و تثبیت ریزگردها صورت پذیرفت .در این مطالعه از جلبک منتسب به گونه Chlamydomonas sp و سیانوباکتر منتسب به گونه Anabaena sp برای تشکیل پوسته زیستی در چهار نمونه خاک از بستر فعلی دریاچه(A) ، بستر قبلی دریاچه(B) ، اراضی تحت تاثیر دریاچه (C) و تپههای شنی قوم تپه (D) استفاده شد و چهار نمونه خاک از عمعقcm۱۰ - ۰این مناطق تهیه شد .ویژگی بارز خاکهایA ، B و C شوری بسیار زیاد) به ترتیب EC برابر با۱۰۸ ، ۱۴۰ و ۱۱۸ در عصاره گل اشباع (و سدیمی بودن آنها میباشد .همچنین خاک A دارای کلاس بافت شنلومی و دو خاک دیگر دارای کلاس بافت رسی میباشد .خاک D غیر شور ولی سدیمی بوده و دارای کلاس بافت شنی بود .این مطالعه به طور جداگانه در هر کدام از خاکها در قالب طرح کاملا تصادفی با چهار تیمار شاهد(T۰) ، جلبک(T۱) ، سیانوباکتری (T۲) و مخلوط مساوی جلبک و سیانوباکتری (T۳) با سه تکرار پیاده شد .برای انجام آزمایش خاک را داخل سینیهای مخصوص تونل باد ریخته و سوسپانسیون حاوی میکروارگانیسم با لایه سطحی خاک داخل سینی مخلوط شد .در طول آزمایش هر روز دو نوبت صبح و عصر آبپاشی صورت پذیرفت .در پایان زمان انکوباسیون (۹۰ روز (برخی ویژگیهای نمونهها نظیرpH ،EC ، کلروفیلa ، کربوهیدراتهای قابل استخراج با آب سرد(CWEC) ، کربوهیدراتهای قابل استخراج با آب گرم(HWEC) ، کربوهیدراتهای قابل استخراج با اسید سولفوریک(SAEC) ، ماده آلی، ضخامت پوستهها، مقاومت فروروی، سرعت آستانه فرسایش بادی و میزان هدر رفت خاک در تونل باد اندازهگیری شد .همبستگی بین ویژگیهای اندازه گیری شده با نرمافزار SPSS و تجزیه واریانس بین تیمارها و نیز مقایسه میانگین بین تیمارها با نرمافزار MSTATC مورد تحلیل آماری قرار گرفت .در این تحقیق میزان کلروفیل a به عنوان شاخصی از جمعیت میکروارگانیسمها در نمونهها مورد استفاده قرار گرفت .بر اساس نتایج حاصله در تیمار T۲ خاک A و در تمامی تیمارهای خاک D مقدار کلروفیل a نسبت به شاهد افزایش معنیدار داشت و ضخامت پوسته در تمامی خاکها در اثر تلقیح میکروارگانیسمها افزایش نشان داد .اما تأثیر آنها فقط در خاکهای A و D معنیدار شد .در خاک A تلقیح میکروارگانیسم باعث شد که سرعت آستانه فرسایش بادی در تیمارهایT۱ ، T۲ و T۳ به ترتیب۴۶ ، ۳۴ و ۵۵ درصد نسبت به شاهد افزایش یابد و در خاک D همه تیمارها سبب شدند که سرعت آستانه فرسایش بادی تقریبا دو برابر تیمار شاهد شود .افزایش در همه تیمارها نسبت به شاهد تقریبا دو برابر بود .با این حال میزان هدررفت خاک در آزمایشهای تونل باد تنها در تیمار T۲ و T۳ این دو خاک معنیدار بوده و تیمار T۱ تأثیری در کاهش میزان هدررفت خاک نداشت .وجود همبستگی بین میزان کلروفیل a و شوری نشان دهنده نقش مهم شوری در جلوگیری از رشد میکروارگانیسمها و ایجاد پوسته زیستی در نمونههای مورد مطالعه میباشد .در کل بر اساس نتایج بدست آمده میتوان نتیجه گرفت که شوری سبب کاهش رشد میکروارگانیسمها در خاکهای شور منطقه میشود و در خاکهای ریز بافت نقش شوری در جلوگیری از رشد میکروارگانیسمها بارزتر است .همچنین کاربرد توأم جلبک و سیانوباکتری سبب همافزایی رشد آنها و در نتیجه سبب حفظ بهتر خاک در مقابل فرسایش بادی میشود.
Text of Note
Nowadays, drying of the Urmia Lake as a largest saline lake in the world and emerging it's saline bed from water has caused the risk of salty dune storms which threats the health of human society and also plants and animal communities living in the region. Biological soil crusts (BSCs) as a dust stabilizers attracted the attention of Soil conservation experts in recent years. Although, the presence of water by the impenetrable lake bed and endorheic basin can be an advantage to create BSCs, but the extraordinary of the lake bed salinity is a factor for prevention of its establishment in the region. Therefore, the present research work has been carried out to investigate the effects of inoculating the Cyanobacteria, algae and their combination to create BSCs for dust control. In this study, an algae attributed to Chlamydomonas sp, and a cyanobacteria attributed to Anabaena sp isolated from the soils of Urmia Lake margin were used to create BSC in four soil samples which collected from 0-10 cm of the current margin (A), the previous bed (B), affected lands by lake (C) and Quomtappe sand dune (D). The main characteristics of the A, B and C soil samples are their highly salinity (their ECe are 108, 140 and 118 dS/m, respectively) and sodicity. Also, texture class of the soil A was loamy sand and other two soils had clay textures. Soil D was Non-saline, but it was sodic with a sandy texture class. This study was conducted separately in each soil in a completely randomized design under four inoculation treatments of non-inoculated (T0), Algae (T1), cyanobacteria (T2) and equal mixture of algae and cyanobacteria (T3) with three replication. In the experiment, the soil was placed into wind tunnel trays and a suspension containing microorganisms mixed with the trays surface soil. During the experiment, water was sprayed to the trays at the morning and evening of every day. After passing the incubation period (30 days), some characteristics of samples such as pH, EC, cold water extractable carbohydrate (CWEC), hot water extractable carbohydrate (HWEC), sulfuric acid extractable carbohydrate (SAEC), organic matter, crust thickness, penetration resistance, wind erosion threshold velocity and soil loss in the wind tunnel were measured and Correlation between the measured characteristics was obtained through the SPSS software. Analysis of variance and so comparison between the means of treatments were analyzed with MSTATC software. In this research, Chlorophyll an amount, was used as an indicator of the microorganism's population in the samples. Based on obtained results the amount of Chlorophyll a in the T2 treatment of soil A, and all treatments of soil D was significantly increased in comparison to the control and crust thickness showed increase in all treatments by microorganisms inoculation. But effect of the treatments was significant in soils A and D. At all treatments inoculation of microorganisms in soil A caused to increase 46, 34 and 55 of the wind erosion threshold velocity in T1, T2 and T3 treatments in comparison to the control, respectively, and in soil D all treatments caused wind erosion threshold velocity became two times more than control. However, soil loss in the wind tunnel experiments was significant in T2 and T3 treatments of these soils and T1 treatment had no effect in reducing soil loss. Correlation between Chlorophyll a and salinity shows the important role of salinity in microbial growth prevention and formation of BSCs in the studied samples. In general, according to the obtained results, it can be concluded that salinity reduces the growth of microorganisms in saline soils of the region, and in soils with fine textures, salinity role in prevention of the microbial growth is clear. Also, using the mix of algae and cyanobacteria together, caused the synergistic growth of them and, consequently, better protection of the soil against wind erosion was provided