Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8363137 | Soil Biology and Biochemistry | 2018 | 4 Pages |
Abstract
Belowground microbial nitrogen (N) processes play key roles in regulating terrestrial ecosystem services such as vegetation production, however, our understanding of their responses to climate change remains limited. We determined patterns and controls of five gross N transformation processes along a typical aridity gradient on the Tibetan Plateau. Potential gross N transformation rates responded diversely to the changing aridity. Both mineralization (MN, average rate: 2.87 mg N kgâ1 soil dâ1) and ammonium immobilization (INH4, 3.35 mg N kgâ1 soil dâ1) declined as aridity increased. Autotrophic nitrification (ONH4, 1.72 mg N kgâ1 soil dâ1) exhibited a bell-shaped pattern along the gradient, with an optimum aridity of 0.53 (1- aridity index (AI)). By contrast, rates of nitrate immobilization (INO3, 0.46 mg N kgâ1 soil dâ1) and dissimilatory nitrate reduction to ammonium (DNRA, 0.10 mg N kgâ1 soil dâ1) did not respond to the changing aridity. These results suggest that predicted increases in aridity will exert different effects on various soil internal N cycling processes, and thus potentially have profound impact on structure and function of dryland ecosystems.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Soil Science
Authors
Dan Kou, Yunfeng Peng, Guanqin Wang, Jinzhi Ding, Yongliang Chen, Guibiao Yang, Kai Fang, Li Liu, Beibei Zhang, Christoph Müller, Jinbo Zhang, Yuanhe Yang,