fa تأثیر گلسنگ بر جوانه‌زنی گونه‌های ,Stipa caucasica Schmalh ,Melica ciliata L ,Bromus tectorum L Taeniatherum caput-medusae (L.) Nevski تخصصي Special پژوهشي Research <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">وجود</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">پوشش</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">گیاهی</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">پراکنده</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">از</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">ویژگی‌های</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">مناطق</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">خشک</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">و</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">نیمه‌خشک</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">است</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">و</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> در برخی موارد </span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">فضای</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">خالی</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">بین</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">این</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">گیاهان</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">با</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">پوسته</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">‌</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">های زیستی</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">مانند</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">گلسنگ‌</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">ها،</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">پوشیده</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">می</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">‌</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">شود.</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">این</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">پوسته</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">‌ه</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">ا</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">در</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">یک</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">اکوسیستم</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> مرتعی </span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">از</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">جهات</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">گوناگون</span></span> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">اهمیت</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> دارند و تأثیرات متعددی بر جوانه‌زنی و زنده‌مانی گیاهان آوندی می‌گذارند. در این تحقیق تأثیرگذاری گلسنگ‌ها به‌عنوان بخش مهمی از پوسته‌های زیستی بر جوانه‌زنی گیاهان علفی غالب مراتع استپی واقع در پارک ملی گلستان بررسی شده است. به‌منظور بررسی تأثیر گلسنگ‌ها بر جوانه‌زنی گیاهان، ابتدا بذرهای چهار گونه گیاهی غالب منطقه شامل:</span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">,Stipa caucasica</span></span></span></em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;"> ,<em>Bromus tectorum Melica ciliata</em></span></span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> و</span></span> <em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">Taeniatherum caput-medusae</span></span></span></em> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">از عرصه جمع‌آوری شده و</span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> سه تیمار مختلف شامل گلسنگ زنده، حذف گلسنگ و کنترل در آزمایشگاه بر درصد جوانه‌زنی و سرعت جوانه‌زنی </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">(</span></span><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">(t₅₀</span></span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> این بذور مورد بررسی قرار گرفت. نتایج به‌دست آمده نشان داد که درصد جوانه‌زنی دو گونه </span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">Stipa caucasica</span></span></span></em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;"> ,<em>Bromus tectorum</em></span></span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> در تیمارهای مختلف با هم اختلاف معنی‌داری داشتند و میانگین درصد جوانه‌زنی چهار گونه </span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">&nbsp;S. caucasica ,M. ciliata ,B. tectorum</span></span></span></em><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">و</span></span> <em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">&nbsp;T. caput-medusae</span></span></span></em><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">به‌ترتیب برابر با 4/86، 47/95، 2/51 و 13/94 درصد بود. </span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">هم‌چنین </span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">سرعت جوانه‌زنی سه گونه </span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">M. ciliata ,</span></span></span></em><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">S. caucasica</span></span></span></em><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> و </span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">T. caput-medusae</span></span></span></em> <span style="font-family:b nazanin;"><span style="font-size:12.0pt;">در بین تیمارها تفاوت معنی‌داری داشت، به‌طوری‌که </span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">میانگین سرعت جوانه‌زنی بذرهای </span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">S. caucasica ,M. ciliata</span></span></span></em><span dir="LTR"><span style="font-family:times new roman,serif;"> ,</span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">B. tectorum</span></span></span></em> <span style="font-family:b nazanin;"><span style="font-size:10.0pt;">و </span></span><em><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">T. caput-medusae</span></span></span></em><span style="color:black;"><span style="font-family:b nazanin;"><span style="font-size:12.0pt;"> به‌ترتیب برابر با 57/0، 62/2، 06/6 و 75/2 </span></span></span><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">روز بود</span></span><strong><span style="font-family:b nazanin;"><span style="font-size:12.0pt;">.</span></span></strong> Patchy vegetation is the main characteristic of arid and semi-arid lands. Gaps between patches in some cases are covered with biological soil crust such as lichens and these crusts have important ecological roles such as influence on germination and plant survival. In this research, effects of lichens as an important biological crust on the germinations of some rangeland species were investigated in Golestan national parks. Seeds of 4 plant species including <em>Stipa caucasica</em>,<em> Bromus tectorum, Melica ciliate</em>, and <em>Taeniatherum caput-medusae</em> were collected and in a laboratory experiment effects of live lichen and removed lichen versus control were studied on germination percentage and speed (T₅₀) of these species. Results showed that germination percentage of <em>Stipa caucasica</em> and <em>B. tectorum </em>had significant differences among treatments and mean germination percentage of <em>B. tectorum, M. ciliata, S. caucasica</em> and<em> T.caput-medusae</em> were 86.4, 95.47, 51.2 and 94.13 percent respectively. Germination speed of <em>S. caucasica</em>,<em> M. ciliata </em>and<em> T. caput-medusae</em> varied significantly and the mean germination speeds of <em>B. tectorum, M. ciliata</em>, <em>S. caucasica </em>and <em>T. caput-medusae</em> were 0.57, 2.62, 6.06 and 2.75 days. پوسته‌های زیستی خاک, گلسنگ, جوانه‌زنی, مراتع استپی, پارک ملی گلستان. Biological soil crust, Lichen, Germination, Steppe Rangelands, Golestan National Park. 223 231 http://rangelandsrm.ir/browse.php?a_code=A-10-287-53&slc_lang=fa&sid=1 Negar Ahmadian نگار احمدیان 10031947532846007155 10031947532846007155 No Mehdi Abedi مهدی عابدی Abedimail@Gmail.com 10031947532846007156 10031947532846007156 Yes Mohammad Sohrabi محمد سهرابی 10031947532846007157 10031947532846007157 No