Impacts of urea N addition on soil microbial community in a semi-arid temperate steppe in northern China |
| |
Authors: | Naili Zhang Shiqiang Wan Linghao Li Jie Bi Mingming Zhao Keping Ma |
| |
Institution: | 1. Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, No.20, NanXinCun, Xiangshan, Beijing, 100093, China 2. College of Life Sciences, Northeast Normal University, Changchun, 130024, China
|
| |
Abstract: | Nitrogen (N) addition has been well documented to decrease plant biodiversity across various terrestrial ecosystems. However, such generalizations about the impacts of N addition on soil microbial communities are lacking. This study was conducted to examine the impacts of N addition (urea-N fertilizer) on soil microbial communities in a semi-arid temperate steppe in northern China. Soil microbial biomass carbon (C), biomass N (MBN), net N mineralization and nitrification, and bacterial and fungal community level physiological profiles (CLPP) along an N addition gradient (0–64 g N m?2 year?1) were measured. Three years of N addition caused gradual or step increases in soil NH4-N, NO3-N, net N mineralization and nitrification in the early growing season. The reductions in microbial biomass under high N addition levels (32 and 64 g N m?2 year?1) are partly attributed to the deleterious effects of soil pH. An N optimum between 16 and 32 g N m?2 year?1 in microbial biomass and functional diversity exists in the temperate steppe in northern China. Similar N loading thresholds may also occur in other ecosystems, which help to interpret the contrasting observations of microbial responses to N addition. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|