نوع مقاله : علمی - پژوهشی
نویسندگان
1 دانشیار گروه جنگلداری، دانشگاه علوم کشاورزی و منابع طبیعی ساری.
2 علوم و مهندسی جنگل، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ایران
3 گروه آمار، دانشگاه تربیت مدرس تهران، ایران
4 گروه هواشناسی کشاورزی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The present study was conducted in the Alandan area–Sari. Five common types of land-uses, namely beech stand and destructed forest stand, ash plantation, pine plantation and arable land were selected for investigation the trend of soil carbon, nitrogen and soil aggregate stability changes with increasing depth under different land uses. The soil samples were taken from soil depths 0-10, 10-20 , 20-30, 30-40, 40-50 cm using coring (8 cm diameter) and auger method in each site systematic randomly (n=6). The soil texture, soil pH, the percentage of CaCO3, organic carbon, total nitrogen and geometric mean diameter (soil aggregate stability index) was measured in the laboratory. The result showed that, soil carbon and nitrogen were significantly (p<0.05) affected by soil depth and land use change. However, the geometric mean diameter was only affected by soil depth. The compared means showed that, the amount of carbon, nitrogen and soil aggregate stability index is significantly reduced with increasing soil depth. In the surface soil layers, the highest carbon (4.6%) and nitrogen (0.31%) were found in ash plantation and theirs lowest (2.5 % and 0.15% respectively) were observed in pine plantation. Also, soil organic carbon is significantly (p<0.05) increased with increasing geometric mean diameter. The land use type significantly affected the vertical distribution of soil carbon and nitrogen. So that, the amount of these characteristics in soil surface layers (0-20cm) have been different from other depth in ash plantation.
کلیدواژهها [English]