Soil Respiration in a Desert Steppe Varies by Different Grazing Regimes in Northern China

Recent studies have identified soil respiration as one of the most important research topics (Thomey et al., 2011) because it is the second largest flux between terrestrial ecosystems and the atmosphere, and plays an important role in regulating the soil carbon (C) pool and ecosystem C-cycling (Saiz et al., 2006). Soil respiration represents the carbon dioxide (CO2) released from the soil surface, generated mainly from a combination of the metabolic activity of roots and microorganisms. Soil temperature, soil water content, plant growth, soil carbon (C) and nitrogen (N) contents all affect soil respiration. In this water-limited ecosystem, we hypothesize that soil respiration will vary with different types of grazing management and that this variation is regulated by grazing-induced changes in abiotic (soil temperature and soil water content) and biotic (plant above-ground and below-ground production) factors