基于BaPS技术的橡胶林土壤呼吸研究

阐明橡胶林生态系统土壤呼吸作用及影响因素,对制定橡胶林土壤管理措施、培育土壤有机碳库和评估区域碳收支平衡具有重要意义。本文采用气压分离技术(Ba PS)研究了橡胶林砖红壤的土壤呼吸速率对温度、水分及碳氮源的响应。结果表明,随着土壤温度(10~30℃)的升高,土壤呼吸速率先增加后下降;土壤孔隙度水(WFPS)为35%~60%时,土壤呼吸速率与其呈显著正相关关系(R~2=0.448,p<0.05)。WFPS为60%~90%,二者呈极显著负相关关系(R~2=0.923,p<0.01);与不施氮相比,低量硝态氮的添加(0.5、2.0、4.0 g/m~2)显著促进了土壤呼吸速率(p<0.05),高量铵态氮的添加(10.0~40.0 g/m~2)则显著抑制了土壤呼吸速率(p<0.05)。土壤呼吸速率与硝态氮、铵态氮(4.0~40.0 g/m~2)均呈显著负相关关系(R~2=0.282,p<0.05;R~2=0.345,p<0.05);与不施碳相比,添加碳(1.0~40.0 g/m~2)激发了土壤呼吸速率(p<0.05),二者呈极显著正相关关系(R~2=0.307,p<0.01)。 

Soil Respiration of Rubber Plantation by BaPS Technique

Understanding soil respiration and its influence factors are important for formulating soil management practices, cultivating soil organic carbon pool, and assessing regional carbon balance in the rubber plantation ecosystem. Soil respiration rate in response to temperature, soil moisture, sources of carbon and nitrogen in the latosols of rubber plantation was studied by barometric process separation (BaPS) technique. The results showed that the soil respiration rate increased first and decreased with the soil temperature increased in the ranges from 10 ℃ to 30 ℃. In addition, soil respiration rate also showed a significant positive correlation (R2=0.448, p<0.05) and a significant negative correlation (R2=0.923, p<0.01) with water-filled pore space (WFPS) in the ranges of 35% to 60% and 60% to 90%, respectively. Compared with no nitrogen fertilization, soil respiration rate (p<0.05) could be significantly enhanced under low nitrate nitrogen addition (0.5, 2.0 and 4.0 g/m ). However, soil respiration rate (p<0.05) could be significantly inhibited by high ammonium nitrogen addition (10.0-40.0 g/m ). There were significantly negative correlation between the soil respiration rate and the addition amount (4.0-40.0 g/m ) of nitrate nitrogen, ammonium nitrogen (R =0.282, p<0.05; R =0.345, p<0.05), respectively. On the contrary, soil respiration rate (p<0.05) could be intensively stimulated by carbon2 addition (1.0-40.0 g/m ) with compared to no carbon application, and there was highly significantly positive correlation (R =0.307, p<0.01) between soil respiration