A Study of Variation Character of Soil Nitrogen Compositions under Drainage Condition in Typical Alpine Marsh Wetlands of the Western Sichuan Plateau

Aiming to understand the variation character of various nitrogen compositions in typical alpine swamp soil,three sites with different ground water tables in Zoige Plateau were selected as test objects in August 2017, soil samples from different layers(0~20 cm, 20~40 cm, 40~60 cm, 60~80 cm)were determined. The result showed that there was significant vertical variation by soil profile in total nitrogen (TN), effective nitrogen (EN), nitrate nitrogen (NN), organic nitrogen (DON). In different layers, there was regular distribution (PM > SM > GM) by wetland types. Nevertheless, ammonia nitrogen (AN) showed considerable spatial variability and less distribution rules, there was significant positive relationship between any two of soil nitrogen compositions. In conclusion:EN, NN and DON will be of great importance in indicating the alpine swamp wetland degradation.