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工业革命以来 ,人类活动所导致的 CO2 等温室气体的浓度在大气中持续上升 ,全球表面温度因此不断升高。在全球温暖化的背景下 ,土壤呼吸与温室效应之间正反馈关系势必影响到未来陆地生态系统功能与全球变化的趋势 ,所以 ,关于土壤呼吸对温度变化响应的研究备受瞩目。土壤呼吸对温度依赖性的研究已经有许多报道 ,其关系可以用简单的指数方程表示。但是 ,土壤水分条件对于土壤呼吸温度敏感性 (用 Q1 0 表示 )的影响却研究得较少。采用碱液吸收法对内蒙古典型温带草原 11个不同水分状况群落的土壤呼吸进行了测定 ,并分析了土壤呼吸的温度敏感性。结果显示土壤呼吸的温度敏感性存在一定程度的空间变异 ,各群落 Q1 0 值平均为 1.6 5 ,变异系数为 6 .94 %。其中 ,春小麦群落的 Q1 0 值最高 (1.84 ) ,其次是湿生杂类草群落 (Q1 0 =1.78) ,而 Q1 0 最低的是冷蒿 (Armesia frigida) -星毛萎陵菜 (Potentilla acaulis)群落 (1.4 7)。用 Spearm an秩相关分析法对表层土壤(0～ 2 0 cm )水分与 Q1 0 值之间的关系进行了分析 ,结果表明各群落 Q1 0 值与生长季土壤平均水分含量呈显著的正相关关系 (R=0 .6 4 5 4 5 ,p=0 .0 32 ) ,说明水分状况对土壤呼吸的温度敏感性有一定程度的影响。由此推断 ,在中国温带草原地区 ,?
Since the Industrial Revolution, the concentration of greenhouse gases such as CO2 caused by human activities has continuously risen in the atmosphere and the global surface temperature has been on the rise. In the context of global warming, the positive feedback relationship between soil respiration and the greenhouse effect will inevitably affect the future terrestrial ecosystem function and the trend of global change. Therefore, the research on the response of soil respiration to temperature changes has drawn much attention. There have been many reports on the temperature dependence of soil respiration, and their relationship can be expressed by a simple exponential equation. However, the effects of soil moisture conditions on soil respiration temperature sensitivity (denoted by Q1 0) have been less studied. The soil respiration of 11 different water status communities in a typical temperate steppe of Inner Mongolia was measured by alkali absorption method. The temperature sensitivity of soil respiration was also analyzed. The results showed that there was some degree of spatial variability in the temperature sensitivity of soil respiration. The average value of Q1 0 was 1.6 5 and the variation coefficient was 6.94%. Among them, the spring wheat community had the highest Q1 0 value (1.84), the second was the wet habitat hybrid community (Q1 0 = 1.78), and the lowest Q1 0 was the Armesia frigida-Potentilla acaulis Community (1.4 7). Spearm an rank correlation analysis was used to analyze the relationship between the water content in the topsoil (0 ~ 20 cm) and the Q1 0 value. The results showed that there was a significant positive correlation between the Q1 0 value and the average soil water content in the growing season (R = 0.46455, p = 0.322), indicating that the moisture status has a certain degree of influence on the temperature sensitivity of soil respiration. Inferred from this, in temperate steppe area of China,?