برآورد کمی ترسیب کربن خاک در سه نوع کاربری (باغ مرکبات، شالیزار و جنگل) در قسمتی از اراضی رامسر، شمال ایران

افزایش غلظت دی اکسیدکربن در جو زمین عامل اصلی تغییرات اقلیمی است که تغییر در اکوسیستم ها از خسارت ناشی از آن هستند. این در حالی است که اکوسیستم ها با پوشش های گیاهی مختلف تاثیر چشمگیری بر ترسیب کربن خاک دارند. این تحقیق به منظور برآورد ترسیب کربن خاک، در سه نوع کاربری شامل باغ مرکبات، شالیزار و جنگل، در شهرستان رامسر انجام گردید. پس از تعیین نقاط مطالعاتی بر روی نقشه، نمونه‌برداری خاک از عمق 0100 سانتیمتری صورت گرفت. مهم‌ترین خصوصیات خاک؛ بافت، ph، کربن آلی، نیتروژن کل، وزن مخصوص ظاهری در آزمایشگاه اندازه گیری شد. در پایان میزان معنی داری کربن ترسیب شده در خاک، با استفاده از تجزیه واریانس و مقایسه میانگین ها به روش دانکن در نرم افزار spssتعیین شد. نتایج نشان دادکه در بین کاربری‌های مختلف از نظر مقدار ترسیب کربن خاک تفاوت معنی داری وجود ندارد. مقدار کل ترسیب کربن خاک در واحد سطح جنگل (35/4532تن در هکتار) بیشتر از باغ مرکبات (66/2997تن در هکتار) و شالیزار (55/2682تن در هکتار) می باشد و بیشترین مقدارنیتروژن،کربن آلی و کربن ترسیب شده در لایه سطحی خاک، عمق 100 سانتی‌متری به میزان (968/866 تن در هکتار) مربوط به جنگل و کمترین به میزان (4/393 تن در هکتار) در کاربری شالیزار می‌باشد. نقشه ترسیب کربن در منطقه مورد مطالعه با روش gis ترسیم گردیده است. به طور کلی، کشاورزی و عملیات زراعی سبب پراکنده شدن خاکدانه ها،کاهش ماده آلی و ترسیب کربن نسبت به خاک های دست نخورده (جنگل) می‌شود.

Quantitative Estimation of Soil Carbon Sequestration in Three Land Use Types (Orchard, Paddy Rice and Forest) in a Part of Ramsar Lands, Northern Iran

Introduction: The increasing Greenhouse Gases in atmosphere is the main cause of climate and ecosystems changes. The most important greenhouse gas is CO2 that causes global warming or the greenhouse effect. One of the known solutions that reduces atmospheric carbon and helps to improve the situation, is carbon sequestration in vegetation cover and soil. Carbon sequestration refers to the change in atmospheric CO2 into organic carbon compounds by plants and capture it for a certain time . However, the ecosystems with different vegetation have Impressive Influence on soil carbon sequestration (SCS). Soil as the main component of these ecosystems is a worldwide indicator which has been known to play an important role in global balance of carbon sequestration. Furthermore, carbon sequestration can be a standard world trade and becomes guaranteed. Costs of transfer of CO2 (carbon transfer From the atmosphere into the soil) based on the negative effects of increased CO2 on Weather is always increasing, This issue can be faced by developing countries to create a new industry, especially when conservation and restoration of rangeland to follow. This research was regarded due to estimation of SCS in three land use types (orchard, paddy rice and forest) in a Part of Ramsar Lands, Northern Iran. Materials and Methods: Ramsar city with an area of about 729/7 km2 is located in the western part of Mazandaran province. Its height above sea level is 20 meters. Ramsar city is situated in a temperate and humid climate. Land area covered by forest, orchard and paddy rice. After field inspection of the area, detailed topographic maps of the specified zone on the study were also tested. In each of the three land types, 500 hectares in the every growing and totally 1,500 hectares as study area were selected .For evaluation the sequestration of carbon in different vegetation systems,15 soil profile selected and sampling from depth of 0 to 100 centimetres of each profile was done by collecting 15 samples with the total number of 45 samples. Soil sampling (at the 0100 cm depth) was carried out following determination of points on map. Some of soil features (i.e., Soil structure, Bulk density ,Texture, Acidity, CEC, total Nitrogen and Organic Carbon) were measured in the laboratory. Then, the ANOVA and Duncan tests were employed due to statistical analysis using of SPSS software package. Also The map of carbon sequestration was prepared using of GIS approach. Results and Discussion :According to obtained results, the amounts of SCS were imposed by different land uses as nonsignificant. The amounts of SCS were found in forest (4532.35 ton/ha), orchard (2997.66 ton/ha) and paddy rice (2682.55 ton/ha) land use, respectively. The differences may be resulted from the variation among the ecosystem types and plant species. Forests are located in wetlands in the high forest and agricultural land more organic carbon levels (0 to 20 cm), but nonsignificant difference was observed in the soil depth in these areas. The Increased amount of carbon sequestration in the Orchard of the Paddy Rice can be interpreted due to longterm use of fertilizer in the orchards. In Paddy Rice of study due to deep plowing, results showed more decline of organic matter and the loss of carbon from soils.In addition, the maximumtotal nitrogen, organic and sequestrated carbon in top soil (010cm depth) were detected in forest (866.968 ton/ha),whereas the least amount dedicated in paddy rice (393.4 ton/ha) land uses. Four classes of detected soil in the study area were included AlfiSols, Inceptisols, Entisols and Mollisols Conclusions: We found no significant differences in terms of carbon sequestration in land use due to the impact of climate, annually high rainfall and washing clay seems logical. The plant communities in forest ecosystems can become more capable to absorb and retain carbon than other vegetation cover. Agriculture and farming operations are due to dispersion aggregates, reduce of organic matter and carbon sequestration compared to forest intact soils. Considering the vital role of soil carbon sequestration as one of the known values in terms of natural ecosystems and the importance of soil conservation programs, further research works are recommended on the effects of biotic factors such as grazing and landuse changes.