准噶尔盆地荒漠-绿洲过渡区土壤呼吸特征

【目的】研究干旱区典型山盆结构下不同土地利用方式的土壤呼吸特征,为干旱区碳过程阐明提供数据支持。【方法】通过LI-8100碳通量测定系统对西北干旱区典型荒漠-绿洲过渡带的自然植被和人工作物覆盖下的土壤呼吸进行两个植物生长时期的监测。【结果】不同植被覆盖条件的土壤呼吸日变化均呈单峰曲线,且日呼吸速率最高值出现在14:00～16:00,最低值出现在02:00～04:00;植物花期的土壤呼吸速率平均值明显高于凋败期;土壤0～5、5～10、10～20 cm温度日变化与土壤呼吸速率变化趋势极为接近。【结论】不同土地利用/覆盖下土壤呼吸特征差异性明显,土壤温度是影响土壤呼吸的关键因子。

Characteristics of Soil Respiration in Desert - oasis Ecotone of Junggar Basin

【Objective】this study was intended to study soil respiration characteristics at typical mountain -basin landscape in different land use patterns,to provide data support for understanding the carbon cycling in arid areas.【Method】Soil respiration was monitored both in natural and agricultural practise by LI-8100 carbon flux measurement system at two growth periods in a typical desert-oasis transition zone in north Xinjiang.【Result】The results showed that the diurnal variation of soil respiration under different vegetation cover is unimodal curve,and the highest respiration rate appears at 14:00-16:00 in a day,the minimum value occurs at 2:00-4:00;The average respiratory rate of soil during the plants florescence is significantly higher than that in phase of decline;The trend of daily variation of 0-5,5-10,10-20 cm soil temperature is very close with that of soil respiration.【Conclusion】The characteristics of soil respiration differs greatly among different land use/cover types.Soil temperature was a key factor affecting soil respiration.