Comparison of concentration of SOC in desert steppe between 2004 and 2010.

†<p>from Wang (2009).</p>‡<p>Figures in parentheses indicate the percent change between the 2004 and 2010 sampling dates.</p

Partial ANOVA table showing degrees of freedom (DF) and <i>P</i>-values from GLM analysis (at α = 0.05) of TN, SOC, MBC and C∶N ratio in the study sites across grazing intensity (GI) and depths (D).

<p>NS not significant.</p

Correlation between SOC, TN, MBC, and C/N for study sites (incorporating all depths and all stocking rates, n = 240 in desert steppe, n = 160 in typical steppe).

**<p>means significant difference at the <i>P</i>≤0.001 level;</p>*<p>means significant difference at the <i>P</i>≤0.05 level;</p>†<p>All values are Pearson correlation coefficient (range 0–1).</p

The relationship of soil organic carbon (SOC) and total nitrogen (TN) storage with years of growing alfalfa in North, Northeast and Northwest region of China.

<p>The relationship of soil organic carbon (SOC) and total nitrogen (TN) storage with years of growing alfalfa in North, Northeast and Northwest region of China.</p

Mean (SE) C∶N ratios (incorporating all depths) and mean (SE) MBC∶SOC ratios (incorporating 0–5 cm and 5–10 cm depths) with different grazing pressure for two sites.

<p>Data in different letters means significant differences between different stocking rates (<i>P</i><0.05).</p

Relationships between SOC or TN (0–60cm) and ≥10°C of the effective total accumulated temperature (T_e) or total precipitation (mm) in the growing reason (P_g) in the North and Northwest region.

<p>Relationships between SOC or TN (0–60cm) and ≥10°C of the effective total accumulated temperature (T_e) or total precipitation (mm) in the growing reason (P_g) in the North and Northwest region.</p

Mean monthly air temperature and rainfall distribution for typical steppe and desert steppe in 2010.

<p>Variation of annual average temperature and annual average precipitation from 1990–2010 in typical steppe and desert steppe.</p

Location of the study areas in China.

<p>Location of the study areas in China.</p

Details of soil samples from alfalfa grasslands growing for different numbers of years in the three regions.

<p>Details of soil samples from alfalfa grasslands growing for different numbers of years in the three regions.</p

Annual precipitation (mm) and annual temperature (°C) in the three regions from 1985 to 2010.

<p>The data from China Meteorological Date sharing Service System: <a href="http://cdc.cma.gov.cn/" target="_blank">http://cdc.cma.gov.cn/</a>.</p