Study On The Contents And The Characteristics Of Main Nutrient Elements In Dominant Tree Species In Greater Khingan Range Inner Mongolia

In this paper, based on the national field research station in The Greater Khingan Mountains Inner Mongolia, the main tree species of Larix gmelinii, Aspen, Birch, Scotch pine, Mongolian oak in Inner Mongolia as the research object, set the standard plot in the stand of different age groups respectively. Through the determination of the vegetation layer and soil layer of nitrogen, phosphorus, potassium content of different forest stand, studing the nitrogen, phosphorus, potassium content and their relationship in different vertical structure of stand, the main conclusions are as follows:(1) In five dominant tree species in the middle age stage, the forest three main nutrient elements are in most is Aspen, to 3.672 g/kg, the least is Birch,25.55 g/kg. The order is Aspen> Mongolian oak> Scotch pine> Larix gmelinii> Birch.Different organs of tree due to different physiological functions, the nutrient demand of different tree species, five main tree species basically performance that the high contents of nutrient elements are in the leaves (19.39 g/kg-281.7 g/kg), the low contents of nutrient elements are in the stems (5.57 g/kg-21.47 g/kg).(2) Nitrogen content of Larix gmelinii leaves is decreased along with the age growth, content of phosphorus is increased with the growth of the age, potassium content is decreased with the growth of age; nitrogen content, phosphorus content, potassium content of Birch leaves are increased along with the age growth; nitrogen content, phosphorus content, potassium content of Aspen leaves is showed the trend of first increased and then decreased along with the age growth; nitrogen content of Mongolian oak leaves is showed first increased and then decreased trend along with the age growth, phosphorus content increased with age and gradually reduce, potassium content is showed reduced after the first increase in the trend along with the age growth.(3) Nitrogen content showed that:tree layer> herb layer> shrub layer, shrub layer, herb layer phosphorus content is higher, the phosphorus content of tree layer is the lowest, potassium content in herb layer is the most, the potassium content of shrub layer and tree layer is relatively small. From young forest to mature forest, soil nitrogen, phosphorus and potassium content was K> N> P. the content of nitrogen in the Birch forest soil layer is most, the content of phosphorus of Aspen forest soil layer is the most, the soil potassium content of Mongolian oak forest is the most.Different organs in different tree species with different of nutrient elements in the soil, leaves had higher accumulation ability of N, P, K, stems had lower accumulation ability of N, P, K.