Effects of Simulated Nitrogen Deposition on Soil Respiration in a Populus euphratica Community in the Ebinur Lake Area, a Desert Ecosystem of Northwestern China

PLoS One. 2015 Sep 17;10(9):e0137827. doi: 10.1371/journal.pone.0137827. eCollection 2015.

Abstract

One of the primary limiting factors for biological activities in desert ecosystems is nitrogen (N). This study therefore examined the effects of N and investigated the responses of an arid ecosystem to global change. We selected the typical desert plant Populus euphratica in a desert ecosystem in the Ebinur Lake area to evaluate the effects of N deposition on desert soil respiration. Three levels of N deposition (0, 37.5 and 112.5 kg·N·ha-1·yr-1) were randomly artificially provided to simulate natural N deposition. Changes in the soil respiration rates were measured from July to September in both 2010 and 2013, after N deposition in April 2010. The different levels of N deposition affected the total soil N, soil organic matter, soil C/N ratio, microorganism number, and microbial community structure and function. However, variable effects were observed over time in relation to changes in the magnitude of N deposition. Simulated high N deposition significantly reduced the soil respiration rate by approximately 23.6±2.5% (P<0.05), whereas low N deposition significantly increased the soil respiration rate by approximately 66.7±2.7% (P<0.05). These differences were clearer in the final growth stage (September). The different levels of N deposition had little effect on soil moisture, whereas N deposition significantly increased the soil temperature in the 0-5 cm layer (P<0.05). These results suggest that in the desert ecosystem of the Ebinur Lake area, N deposition indirectly changes the soil respiration rate by altering soil properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry
  • Carbon / metabolism
  • China
  • Desert Climate
  • Ecosystem
  • Lakes / chemistry
  • Nitrogen / chemistry
  • Nitrogen / metabolism*
  • Populus / metabolism*
  • Soil / chemistry*
  • Soil Microbiology
  • Temperature
  • Water / chemistry

Substances

  • Soil
  • Water
  • Carbon
  • Nitrogen

Grants and funding

This work was supported by grants from the International Science & Technology Cooperation Program of China (2010DFA92720), the Open Project from Key Laboratory of the Xinjiang Uygur Autonomous Region (2015KL004), the National Natural Science Foundation of China (41571034), the State Key Program of National Natural Science of China (41130531), and the Ministry of Education Innovation Team Project (IRT1180). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.