برنامه ریزی طرح های مدیریت منابع جنگلی در سامان های عرفی کوهستان هزار مسجد (مطالعه موردی: سامان های عرفی سرچاه بالا، سرچاه پایین و زیر دلوچه) (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
مدیریت جنگل های کوهستانی در سراسر جهان امری بسیار چالش برانگیز است. چراکه استفاده جوامع ساکن در مجاورت مناطق کوهستانی پرجمعیت از خدمات اصلی اکوسیستم جنگل (تولید چوب، دامداری متحرک، تفرج، حفاظت از تنوع زیستی و ذخیره کربن) می تواند منجر به کاهش نقش خدمات حفاظت آن در برابر خطرات گرانشی (سیل، رانش و ذخیره آب) شود. در این پژوهش با استفاده از روش تصادفی - سیستماتیک در یک شبکه آمار برداری 500×500 متر اقدام به نمونه برداری از جنگل های ارس موجود در سامانه های عرفی سه گانه «سرچاه بالا- سرچاه پایین – زیر دلوچه» در کوهستان هزار مسجد گردید. متغیر های پوشش جنگلی با استفاده از دستور العمل آمار برداری جنگل اداره فنی جنگل داری و جنگل کاری و روش نمونه برداری تلفیقیی خط- پلات (پلات های 50×20 متر و ترانسکت 300 متر) برآورد شد. سپس داده های پوشش جنگلی با داده های زمین شناسی، اقتصادی- اجتماعی، توپوگرافی تلفیق و در نهایت برنامه های مدیریتی در واحد های کاری ارائه گردید. میانگین واقعی درصد تاج پوشش جنگلی در کل سامان های عرفی سه گانه، به احتمال 95 درصد 940/0 ± 018/6 بود. میانگین تعداد در هکتار زادآوری، عناصر چوبی با قطر کمتر از 2 متر و بیش از 2 متر به ترتیب 6/53، 95/105 و 4/69 و میانگین تعداد در هکتار کل، مجموعاً 9/228 اصله درخت بوده است. در شش واحد کاری مجموعاً به مساحت 414 هکتار، میانگین ارتفاع از سطح دریا 2101 متر، بارندگی 9/371 mm، درجه حرارت سالیانه 1/8 درجه سانتی گراد، شیب متوسط 4/57 % دارای سازند مزدوران با برونزدسنگی 75 تا 90 درصد، خاک صخره ای و سنگلاخی و میانگین تاج پوشش درختی و درختچه ای 10-5 و 5-1 درصد، پروژه حفاظت پیشنهاد شد. در هفت واحد کاری دیگر به مساحت 658 هکتار، میانگین ارتفاع از سطح دریا 2147 متر، بارندگی 2/376 mm، درجه حرارت سالیانه 9/7 درجه سانتی گراد، شیب متوسط 2/34 %، سازند شوریجه با برونزدسنگی 25 تا 50 درصد، خاک عمیق با بافت شنی- لومی، تاج پوشش درختی و درختچه ای 10-5 و 5-1 درصد، نهال کاری با ارس و گونه های همراه پیشنهاد گردید. نتایج این تحقیق، تراکم و درصد تاج پوشش درختان ارس بسیار بالا در یک اکوسیستم غنی و منحصر به فرد را نشان می دهد که می بایست حفاظت دقیق از آن ها به عنوان منابع ژنتیکی بسیار ارزشمند جوامع ارس شمال شرق ایران با جدیت در دستور کار قرار گیرد.Planning Forest Resource Management Projects in Ranches of the Hezar Masjed Mountains (Case Study: Ranchs of Sarchah Bala, Sarchah Payin, and Zirdaloucheh)
Introduction Mountains cover 24% of the Earth's total surface, and 12% of the global population directly depends on mountainous ecosystem services for their livelihoods and well-being. They serve as habitats for numerous plant and animal species and are often considered specific refuges and hotspots of biodiversity. Mountains represent a highly complex geosystem, comprising a collection of very sensitive ecosystems that are particularly vulnerable to human interventions. Mountain ecosystems provide a wide array of products and services to the people residing in these areas, offering spaces for livestock grazing, firewood collection, timber for rural home construction, and the harvesting of medicinal and edible plants. Species of the genus Juniperus play a significant role in maintaining the ecological services of high-altitude mountain ecosystems, extending from the Himalayas and Western China to the Near East, Central Asia, the Indian subcontinent, the Middle East, Southern Europe, the Mediterranean, parts of Africa, and even into the high elevations of North America, southwestern United States, and Mexico. They often constitute the only source of support for local communities. The activities of these residents frequently result in the substitution of Juniper forests' services with alternative ecosystem services, such as agriculture, horticulture, and transhumant livestock farming in these mountainous regions. The irrational use of these sensitive and vulnerable ecosystems has led to significant disruptions in their functioning. Limited frameworks for management aimed at enhancing the resilience of ecosystems in arid and semi-arid regions against drought effects and human interventions are available. This challenge is particularly acute in Juniper forests, which have experienced significant loss of their native trees over the past few decades. In Iran, such ecosystems, particularly in the Hezar Masjed Mountains of Khorasan, are managed through the framework of ranches due to the clash between the needs of local residents and those of herders with customary ownership rights. Currently, the preparation and development of all forestry and rangeland management programs emphasize the study and statistical evaluation of vegetative elements, including both tree and shrub species, which play a central role. The proposed practical solutions in the plans are based on these evaluations. Methodology In this study, a systematic random sampling method was employed by selecting a 500×500-meter statistical grid to sample the Juniper forests within the ranch units of "Sarchah Bala, Sarchah Pain, and Zireh Dalucheh," covering an area of 1,081 hectares in the Hezar Masjed Mountains. To estimate canopy cover and the number of forest trees per hectare, the forest inventory guidelines from the Technical Forestry and Afforestation Department were utilized, employing a combined sampling method of transect-plot (with plots of 50×20 meters and a transect of 300 meters). To achieve statistical accuracy in tree cover sampling within the Juniper communities, the required number of plots was first determined by the pilot sampling before conducting the final inventory. Upon analyzing the data concerning tree and shrub cover, these were integrated with geological, topographical, soil, and socio-economic data to ultimately provide a management plan for the operational units. Results A total of 15 tree and shrub species were recorded in the ranches, with the highest abundance and canopy cover percentage attributed to the Juniper species. The true average canopy cover percentage for the studied area was estimated to be 0.940 ± 0.018 at a 95% confidence level. The average number of individuals per hectare for regeneration and woody elements with diameters less than 2 meters and greater than 2 meters was 53.6, 105.95, and 69.4, respectively, summing to a total average of 228.9 individuals per hectare. In six operational units encompassing a total area of 414 hectares, a protective management plan was proposed. These areas were characterized by the average elevation of 2,101 meters above sea level, an annual rainfall of 371.9 mm, an annual temperature of 8.1 ºC, and an average slope of 57.4% the Mozduran formation, exhibiting 75 to 90 percent rocky outcrops, rocky and gravelly soils, and an average tree and shrub canopy cover of 5-10% and 1-5%. In other seven operational units covering 658 hectares, the planting of juniper seedlings and accompanying species was proposed, where characterized by the average elevation of 2,147 meters, rainfall of 376.2 mm, an annual temperature of 7.9 ºC, and an average slope of 34.2%. The Shurijeh formation in these units showed 25 to 50 percent rocky outcrops, deep sandy-loamy soils, and a tree and shrub canopy cover was 5-10% and 1-5%. Discussion In the three ranches, a total of 27 users reside in the downstream rural areas and are allowed to use these pastures for 73 days each year. However, it remains unclear whether the duration of their usage is effectively monitored. These pastures, located at an average elevation of 2100 meters above sea level, experience an annual average temperature of approximately 8 degrees Celsius, and precipitation mainly occurs in the form of snow. Consequently, the trees and shrubs in the region have a short growing season and limited annual growth. Furthermore, the cold and dry climate makes natural regeneration conditions significantly more challenging. This is evident as the majority of woody species regeneration is attributed to juniper, barberry, and wild rose, which are not particularly palatable for livestock. In most areas, over 90% of the forest composition is dominated by juniper species. The decrease in species mixing due to human activity impacts biodiversity and the survival of animal species, particularly birds. Within the entire watershed of these regions, there are at least four species of wild cherries and several endemic species, of which only a small population remains. Conclusion The forests studied in the three ranches are primarily composed of juniper trees that are notably tall and possess large crown diameters, particularly in the upper reaches of the management systems. The junipers in these areas are mature and have thick trunks, making them valuable resources for seed production. Occasionally, they form dense stands, with their canopy coverage sometimes exceeding 20%, which is unique within Iran. Therefore, it is essential to protect these valuable genetic resources by designating them as protected areas for future generations.
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