土壤异养呼吸温度敏感性（Q10）的影响因子

Controls on the Temperature Sensitivity of Soil Heterotrophic Respiration： Q10 Variability and Analysis

首先对国内外土壤异养呼吸Q10的研究成果进行了全面的综合述评．影响土壤异养呼吸Q10的因子主要包括环境因子（主要是温度和湿度）、呼吸底物和土壤生物等．较多的研究表明土壤异养呼吸的Q10在低温时较高，高温时较低，但Q10也可随温度升高而增加，或随温度变化而保持稳定；通常土壤异养呼吸的Q10与土壤水分成正相关，但极端水分条件下（干旱胁迫或渍水）Q10较低；有限的研究表明呼吸底物和土壤生物对土壤异养呼吸Q10的影响还具有很大的不确定性；调控土壤异养呼吸Q10的机理目前还不清楚．然后从温度、水分、呼吸底物、土壤微生物对土壤异养呼吸Q10的影响等方面对影响土壤异养呼吸温度敏感性的原因进行了深入的探讨，并提出未来应重点开展的研究：（1）加强不同尺度土壤异养呼吸Q10的影响因子及调控机理研究；（2）扩大土壤异养呼吸Q10的野外研究；（3）扩大热带、亚热带土壤异养呼吸Q10的研究；（4）深入探讨呼吸底物有效性和土壤生物对土壤异养呼吸Q10的影响；（5）加强其他因子对土壤异养呼吸Q10影响的研究．

Soil heterotrophic respiration （SHR） of terrestrial ecosystems is a major flux in the global carbon cycle and at the same time a potentially important mechanism of positive feedback to climate change. Q10 value （an indicator of temperature sensitivity） of SHR are usually affected by a range of factors such as temperature, water content, respiratory substrate anti soil organisms. These factors substantially evoke temporal and spatial variability of Q10. Generally, Q10 value of SHR decreases with increasing temperature, but can under some conditions increases with increasing temperature, or even remains constant as temperature changes. Q10 value of SHR often increases positively with soil water content, but under extreme water conditions, such as desiccation stress or waterlogged, Q10 goes down. There still remains a lot of uncertainty of the effects of respiratory substrate and soil organisms upon Q10 of SHR. By now, the mechanistic understanding of how temperature and other factors affect Q10 of SHR is still lacking. The uncertainty will be reduced by deepening research on controls of Q10 and its intrinsic mechanisms at different scales, paying more attention to field work, expending research within tropical and subtropical areas, and enhancing emphasis to the effects of substrate availability and soil organisms, etc.