بررسی ترکیب و تنوع گیاهی و عوامل مؤثر بر آن در طبقات مختلف ارتفاعی در منطقه آلوارس- قله سبلان

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری علوم مرتع، گروه مرتع و آبخیزداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل، ایران

2 استاد، گروه مرتع و آبخیزداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل، ایران

3 دانشیار، گروه مرتع و آبخیزداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل، ایران

4 استادیار، گروه مرتع و آبخیزداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل، ایران

5 استادیار، بخش تحقیقات جنگلها، مراتع و آبخیزداری، مرکز تحقیقات، آموزش و ترویج کشاورزی و منابع طبیعی استان گیلان، سازمان تحقیقات، آموزش و ترویج کشاورزی، رشت، ایران

6 استادیار، مرکز تحقیقات، آموزش و ترویج کشاورزی و منابع طبیعی استان اردبیل، سازمان تحقیقات، آموزش و ترویج کشاورزی، اردبیل، ایران

10.22092/ijfrpr.2023.362660.1588

چکیده

سابقه و هدف: اکوسیستم‌های کوهستانی نقش مهمی در ثبات اکوسیستم به‌ویژه برای حفاظت از تنوع زیستی و توسعه پایدار و حفظ امنیت اکولوژیکی دارد. این پژوهش، با هدف بررسی وضعیت ترکیب و تنوع پوشش گیاهی و روند تغییرات آنها در پروفیل ارتفاعی آلوارس تا سبلان (2300 تا 4811 متری) در قالب طبقات ارتفاعی مختلف در دامنه جنوب‌شرقی، به‌منظور حراست از ذخایر ژنی و مدیریت مراتع منطقه انجام شد.
مواد و روش‌ها: پس از بررسی‌های میدانی و با توجه به امکان دسترسی به مراتع منطقه، نه طبقه ارتفاعی (سایت) مشخص شد، در هر سایت سه ترانسکت 100 متری و در امتداد هر ترانسکت 10 پلات یک متر‌مربعی با فاصله 10 متر از هم مستقر گردید. گونه‌های گیاهی از سطح پلات‌ها جمع‌آوری و بعد در هرباریوم شناسایی شدند. در هر پلات درصد تاج‌پوشش گیاهی و تراکم گونه‌ها ثبت شد. بالاترین ارتفاعی که منجر به جمع‌آوری نمونه‌های گیاهی شد، ارتفاع 4480 متری سبلان بود. برای بررسی تنوع و غنای گونه‌های گیاهی از شاخص‌های شانون، سیمپسون، مارگالف و منهینیک استفاده شد. با استفاده از اطلاعات مربوط به اندازه‌گیری درصد پوشش تاجی و تعداد گونه‌های مشاهده‌شده، شاخص‌های تنوع، غنا و یکنواختی گونه‌ای برای سایت‌های انتخابی محاسبه شد. برای بررسی اختلاف در بین سایت‌ها در طبقات ارتفاعی مختلف از تجزیه واریانس یک‌طرفه (ANOVA) و به‌منظور مقایسه میانگین‌ها از آزمون دانکن (Duncan) استفاده شد. شاخص‌های مختلفی برای تعیین تنوع گونه‌ای کاربرد دارد که از بین آنها از دو شاخص سیمپسون و شانون– وینر استفاده شد. غنای گونه‌ای نیز با استفاده از شاخص‌های مارگالف و منهینیک تعیین شد و آنالیزهای مربوط به رسته‌بندی پوشش گیاهی شامل آنالیز تطبیقی متعارفی (CCA) بود.
نتایج و یافته‌ها: نتایج نشان داد، خانواده Asteraceae با 31 گونه و Astragalus با 10 جنس شاخص‌ترین عناصر فلور منطقه هستند و 51 گونه به ناحیه ایران– تورانی تعلق داشتند، بر‌اساس نتایج حاصل از این پژوهش 33 درصد گونه‌های شناسایی‌شده مربوط به ناحیه ایران- تورانی بوده است. فرم‌های همی‌کریپتوفیت‌ها (He) با 54 درصد و تروفیت‌ها (Th) با 22 درصد فراوان‌ترین اشکال زیستی در منطقه بودند. بیشترین مقدار تنوع، غنا و یکنواختی در طبقه ارتفاعی 2200-3200 متری مشاهده شد. نتایج نشان داد، ارتفاع، بارش، دما، میزان شن خاک، شیب و فسفر از عوامل مؤثر بر پراکنش گیاهان بوده است. ‌سازگاری بیشتر گیاهان با شرایط محیطی منطقه، موجب شده است که همی‌کریپتوفیت‌ها تیپ بیولوژیک غالب منطقه را تشکیل دهند، توجیه حضور بالای تروفیت‌ها نیز در نتیجه دخالت‌های انسان و چرای متمرکز دام‌ها، احداث جاده و مکان‌های تفرجگاهی است. در بررسی تأثیر ارتفاع بر ترکیب و تنوع گیاهی می‌توان چنین استنباط کرد که ارتفاع بر ترکیب و تنوع گیاهی تأثیرگذار است.
نتیجه‌گیری: به‌طور‌کلی می‌توان گفت، وضعیت ترکیب و تنوع گونه‌ای در مراتع جنوب‌شرقی سبلان براساس شاخص‌های تنوع و یکنواختی، مراتعی دارای شرایط تنوع متوسط و رو به پایین است، که نشان‌دهنده شدت تخریب در کل عرصه‌های مورد بررسی است، احتمالاً عامل تخریب در ارتفاعات پایین‌تر تأثیر چرای دام‌ها و نیز اثر فعالیتهای گردشگری و پیست اسکی آلوارس بوده و علل تخریب در ارتفاعات بالاتر از 3600 متر، لگدکوبی گیاهان توسط کوهنوردان و در‌نتیجه از بین رفتن گونه‌های گیاهی باشد و به‌طور‌کلی دلیل اصلی پایین بودن تنوع در ارتفاعات بالا نیز به نظر می‌رسد، کاهش دما و شرایط سخت رویش گیاهان باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Investigating the composition and diversity of plants and effective factors in different elevational classes in Alvares-Sabalan peak gradient

نویسندگان [English]

  • Momtaz Alizadeh 1
  • Ardavan Ghorbani 2
  • Mehdi Moameri 3
  • Mikael Badrzadeh Orang 4
  • Mahmoud Bidar Lord 5
  • Jaber Sharifi 6
1 PhD Student of Rangeland Sciences, Department of Range & Watershed Management, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
2 Prof., Department of Range & Watershed Management, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
3 Associate Prof., Department of Range & Watershed Management, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
4 Assistant Prof., Department of Range & Watershed Management, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
5 Assistant Prof., Forests Rangelands and Watershed Management Research Department, Guilan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
6 Assistant Prof., Ardabil Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ardabil, Iran
چکیده [English]

Background and objectives: Mountain ecosystems play an important role in ecosystem stability, especially for biodiversity protection and sustainable development and ecological security. This research was conducted with the aim of the investigating the composition and diversity of plants and the process of their changes in the elevation profile of Alvares to Sabalan (2300 to 4811 meters above sea level) with different elevation classes in the southeast slope, to protect gene reserves and management rangelands in this region.
Methodology: After field investigations and according to the possibility of access to rangeland in the area, nine elevation classes (sites) were determined, three 100-meter transects were established in each site, and 10 one m2 plots were established along each transect with a distance of 10 meters from each other. Plant species were collected from the surface of the plots and then identified in the herbarium. In each plot, the percentage of vegetation cover and the density of species were recorded. The highest elevation that led to the collection of plant samples was Sabalan 4480 meters. Shannon, Simpson, Margalef and Menhinich indices were used to check the diversity and richness of plant species. Using the information related to measuring the percentage of canopy cover and the number of observed species, the indices of diversity, richness and evenness of species were calculated for the selected sites. One-way analysis of variance (ANOVA) was used to investigate the differences between the sites in different elevation classes, and Duncan's test was used to compare the means. Various indices are used to determine species diversity, among which two indices, Simpson and Shannon-Wiener, were used. Species richness was also determined using Margalef and Menhinick indices and analyses related to vegetation ranking including Canonical correspondence analysis (CCA) were performed.
Results: The results showed that the Asteraceae family with 31 species, Astragalus with 10 genera are the most prominent elements of the region's flora. According to the results of this research, 33% of the identified species were related to Iran-Turonian region. The forms of Hemicryptophytes with (54%), Therophytes with (22%) were the most abundant biological forms in the region. The highest amount of diversity, richness and evenness was observed in the elevation class of 2200-3200 meters. The results showed that elevation, precipitation, temperature, soil sand content, slope and phosphorus were effective factors on the distribution of species. The greater compatibility of plants with the environmental conditions of the region has caused hemicryptophytes to form the dominant biological type of the region, the justification for the high presence of Therophytes is also the result of human interference and concentrated livestock grazing, road construction and recreational areas.
Conclusion: In examining the effect of elevation on the composition and diversity of plants, it can be concluded that the elevation affects the composition and diversity of plants, it seems that the condition of the composition and diversity of species in the southeast rangelands of Sabalan, based on the indicators of diversity and evenness, the rangelands have medium diversity conditions and are increasing is low indicating the intensity of destruction in the entire investigated areas, probably the cause of destruction at lower elevation, the impact of livestock grazing, as well as the effects of tourism activities and Alvares ski resort, and the causes of destruction at elevation above 3600 meters, the trampling of plants by mountain climbers and in the result is the loss of plant species. In general, the main reason for the low diversity in high elevation seems to be the decrease in temperature and the harsh conditions for the growth of plants.

کلیدواژه‌ها [English]

  • Alvars
  • elevation gradient
  • life form
  • species evenness
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