TITLE:
Spatial and Temporal Variations in Available Soil Nitrogen—A Case Study in Kobresia Alpine Meadow in the Qinghai-Tibetan Plateau, China
AUTHORS:
Li Lin, Guangmin Cao, Fawei Zhang, Xun Ke, Yikang Li, Xingliang Xu, Qian Li, Xiaowei Guo, Bo Fan, Yangong Du
KEYWORDS:
Available Soil Nitrogen, Source of Nutrient Variation, Temporal Variation, Spatial Variation, Alpine Meadow
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.3,
March
28,
2019
ABSTRACT: Elucidating the factors that determine the effects of temporal and spatial variation of nutrients is important for analyzing the characteristics of an ecosystem. The goal of this paper was to estimate how values obtained using a particular sampling approach correlated with the actual data for an entire plot. The mesh partition method was employed to divide an integrated observing field (IOF) located at the Haibei National Field Research Station of an alpine grassland ecosystem, China, into 25 subplots. Five of the 25 subplots were randomly selected for soil sampling and to determine the source of variations in soil nutrient content from 2001 to 2012. The results showed that, contributions of temporal and spatial variation in available nitrogen in the 0 - 10 cm soil layer accounted for 47.3% and 52.7%, respectively. The contribution of spatial variance was higher than that of temporal variance especially in the surface soil layers. The available soil nitrogen content in the alpine meadow was not obviously affected by fluctuations in rainfall and temperature. Increasing the number of samples could reduce calculation errors in measuring available soil nitrogen content, while collecting a reasonable number of samples can save time and labor.