Effects of temperature and grazing on soil organic carbon storage in grasslands along the Eurasian steppe eastern transect

PLoS One. 2017 Oct 30;12(10):e0186980. doi: 10.1371/journal.pone.0186980. eCollection 2017.

Abstract

Soil represents the largest terrestrial organic carbon pool. To address global climate change, it is essential to explore the soil organic carbon storage patterns and their controlling factors. We investigated the soil organic carbon density (SOCD) in 48 grassland sites along the Eurasian steppe eastern transect (ESET) region, which covers the Inner Mongolia grassland subregion and Mongolia grasslands subregion. Specifically, we analyzed the SOCD in the top 30 cm soil layer and its relationships with climatic variables, soil texture, grazing intensity and community biomass productivity. The results showed that the average SOCD of the ESET was 4.74 kg/m2, and the SOCD of the Inner Mongolia grassland subregion (4.11 kg/m2) was significantly lower than that of the Mongolia grassland subregion (5.79 kg/m2). Significant negative relationships were found between the SOCD and the mean annual temperature (MAT), mean annual precipitation (MAP) and grazing intensity in the ESET region. The MAT and grazing intensity were identified as the major factors influencing the SOCD in the ESET region; the MAP and MAT were the major factors influencing the SOCD in the Inner Mongolia grassland subregion; and the MAT and soil pH were the major factors influencing the SOCD in the Mongolia grassland subregion.

MeSH terms

  • Asia
  • Carbon / analysis*
  • Grassland*
  • Mongolia
  • Soil / chemistry*
  • Temperature*

Substances

  • Soil
  • Carbon

Grant support

This study was supported by the National Key Technology Support Program (2015BAC02B04) and the Natural Science Foundation of Inner Mongolia (2015MS0302). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.