پديد آورندگان :
مهدوي، علي دانشگاه ايلام - د انشكده كشاورزي , رستمي‌نيا، محمود دانشگاه ايلام - د انشكده كشاورزي , بازگير، مسعود دانشگاه ايلام - د انشكده كشاورزي
كليدواژه :
اراضي كشاورزي , پارك جنگلي , جنگل بلوط , كشت زيرآشكوب , استان ايلام
چكيده فارسي :
امروزه، تغيير و تبديل كاربري اراضي جنگلي و مراتع به كشاورزي به يكي از نگراني‌هاي قابل توجه در سطح دنيا در زمينۀ تخريب محيط‌زيست و تغييرات اقليمي جهاني تبديل شده است. هدف از اين مطالعه، بررسي شاخص‌هاي كيفي و مقادير كربن ترسيب‌شده در خاك چهار كاربري جنگل بلوط (طبيعي)، جنگل كاج و سرو (دست‌كاشت)، كشاورزي و كشت زيرآشكوب در جنگل بلوط در محدودۀ پارك جنگلي چقاسبز شهرستان ايلام است. براي اين منظور، در هر كاربري 10 نمونه خاك از عمق 0 تا 30 سانتي‌متر با روش تصادفي سيستماتيك برداشت شدند. علاوه بر اندازه‌گيري ميزان ترسيب كربن خاك، برخي از خصوصيات فيزيكي و شيميايي خاك (نيتروژن، فسفر، پتاسيم، آهك، رس، سيلت، شن، اسيديته، هدايت الكتريكي، جرم مخصوص ظاهري و پايداري خاك) در هر كاربري نيز اندازه‌گيري شدند. نتايج نشان داد كه ترسيب كربن خاك در كشت زيرآشكوب درختان بلوط (09/58 تن در هكتار) و جنگل طبيعي بلوط (72/56 تن در هكتار) به‌طور معني‌داري بيش از دو كاربري جنگل‌كاري كاج و سرو (95/37 تن در هكتار) و اراضي كشاورزي (80/31 تن در هكتار) هستند. اين در حالي است كه ميزان ترسيب كربن خاك بين دو كاربري جنگل طبيعي بلوط و كشت زيرآشكوب درختان بلوط اختلاف معني‌داري را نشان نداد. نتايج اين تحقيق بر ضرورت حفظ كاربري جنگل طبيعي و جلوگيري از تغيير آن به ساير كاربري‌ها از جمله كشاورزي تأكيد دارد.
چكيده لاتين :
Introduction: The rapid concentration of greenhouse gases (GHGs) especially carbon dioxide (CO2) is considered as the main cause of global warming and climate change. Todays, the change and conversion of forest lands and rangelands to agricultural lands has become one of the important concerns in the world in terms of environmental degradation and global climate changes. Land use change causes disturbance of the ecosystem and can influence the carbon stocks and fluxes. Soil organic carbon tends to be decreased when transforming grasslands, forest or other native ecosystems to croplands or agricultural lands. Therefore, the estimation of carbon storage would be useful to evaluate the amount of carbon potentially emitted to the atmosphere due to land use changes.
Aims: The purpose of this study was to investigate the soil quality indices and amount of carbon sequestration in four land uses namely oak forest (natural), pine and cedar (plantations), agriculture, and under tree crown cultivation in oak forests in Chaghasabz forest park in Ilam.
Materials and Methods: For this purpose, 10 soil samples from each land use (total of 40 samples) were taken from 0-30 cm depth of soil using systematic random sampling method. In addition to measuring the amount of carbon content of soil, some physical and chemical properties of soil (nitrogen, phosphorus, potassium, lime, clay, silt, sand, acidity, electrical conductivity, bulk density and soil stability) were also measured in each land use. Statistical analysis of physical and chemical properties of soil for four land-uses was carried out base on a systematic randomized design with 10 replications for each land use. Normality of data using Kolmogorov-Smirnov test and homogeneity of variance of data were analyzed based on Levene test. To compare soil quality and carbon sequestration properties in different land uses, one-way analysis of variance (F test) was used and the Duncan test was used for grouping and comparing the averages at 95% confidence level.
Results: The results showed that the soil carbon sequestration in under tree crown cultivation (58.09 ton/ha) and natural oak forest (56.72 ton/ha) was significantly higher than the two other land uses namely pine and cedar plantation (37.95 t ha-1) and agriculture (31.80 tons / hectare). However, there was no significant difference in soil carbon sequestration between the two land uses namely natural oak forest and under crown oak trees cultivation. The results of Pearson correlation test between soil physical and chemical indices showed that the cation and potassium exchange capacity are positively correlated and lime has a negative correlation with the amount of organic carbon.
Discussion and Conclusion: The results showed that the soil quality in the natural oak forest is more favorable than the other three land uses. Therefore, based on the results of this research, the need for preserving the natural forests and preventing it from changing into other land uses, including agriculture should be emphasized.
