水保所知识产出(1956---)知识库

为研究黄土高原水蚀风蚀交错区不同土地利用方式下的土壤呼吸特征及其对水热因子的响应，于2012 年5 月至10 月，
采用动态密闭气室法（IRGA）对裸地、农地、苜蓿地、柠条地和撂荒地土壤呼吸速率进行连续日动态测定，基于小时测定结果，分析
土壤呼吸特征及其与水热因子的关系。结果显示，土壤呼吸日动态变化为单峰曲线，土壤呼吸速率一般在5：00—7：00（UTC+8）最
低，在13：00—15：00 最高，9：00 和19：00 时土壤呼吸测量值最接近日平均值。土地利用方式显著影响土壤呼吸速率（P<0.01），其均
值大小顺序为：苜蓿地>柠条地>撂荒地>农地>裸地。温度是影响土壤呼吸的决定性因子，土壤呼吸速率与5 cm 土层温度相关程度
最高（P<0.01）。5 月至8 月中旬降雨促进土壤呼吸，8 月下旬至10 月下旬降雨抑制土壤呼吸；水分对土壤呼吸具有双向调节作用：
当0~10 cm 土层含水量低于0.20 cm3·cm-3 时，水分促进土壤呼吸，超过0.20 cm3·cm-3 时抑制土壤呼吸。研究提出的E-P-Q
（Exponential-Piecewise-Coefficient）模型能够合理解释区域内水热因子对土壤呼吸的响应规律。

It is of critical importance to evaluate the regional carbon cycling and balance more accurately as global warming is the key issue
of the climate changes. This research is aimed to reveal the soil respiration（SR）and its responses to soil temperature and water in a waterwind
erosion interlaced zone in the Loess Plateau, China. Hourly SR in bareland, cropland, alfalfa land, cartagena korshinkii land and abandoned
land were measured automatically from May to October, 2012, using Infra-Red Gas Analysis（IRGA）method. Soil temperature at
depth of 5 cm and 15 cm（T5 and T15, respectively）and volumetric water content of 0~10 cm and 10~20 cm soils（VWC0-10 and VWC10-20, respectively）
were also monitored. The SR diurnal dynamics was a single-peak curve, with the peak occurring between 13：00 （UTC+8, similarly
hereinafter）and 15：00, and the trough between 05：00 to 07：00. The SR measured at 9：00 and 19：00 was equal to the daily average
value. Land use patterns had significantly impacts on SR （P<0.01）, with order of alfalfa land> cartagena korshinkii land> abandoned land>
cropland> bare land. The SR had significant positive correlation with T5 , T15 , VWC0~10 and VWC10~20 for five land use patterns, but the correlationship
with soil water was weaker than with soil temperature. The correlation coefficients were greater for T5 than T15 and VWC0~10 than
VWC10-20. The precipitation increased SR during May to late August, but inhibited SR during September to late October. Soil SR increased
with increasing soil water when VWC0~10 was less than 0.2 cm3·cm-3, but decreased as soil water further increased when VWC10~20 was greater
than 0.2 cm3·cm-3. The E-P-Q（Exponential-Piecewise-Coefficient）model could rationally explain relationships between SR and soil
temperature and/or soil water.