摘要
湿地在干旱区发挥着积极的作用,明确湿地土壤活性有机碳组分特征及影响因素对评价干旱区生态系统碳收支平衡有着重要意义。该研究以天山中部北坡的柴窝堡湿地土壤为研究对象,探讨了不同土地利用下干旱区湿地土壤有机碳组分特征。结果表明,柴窝堡湿地不同土地利用方式下,土壤中总有机碳含量特征为湿地垦殖为农田[(22.97±0.85)g·kg^–1]>自然农田[(21.83±1.97)g·kg^–1]>湿地–农田过渡带[(16.74±6.52)g·kg^–1]>湖泊湿地[(11.98±3.67)g·kg^–1]>盐碱湿地[(9.86±3.31)g·kg^–1]。湿地与农田土壤易氧化有机碳含量差异显著(P<0.05)。湿地垦殖为农田的土壤溶解性有机碳含量最高,并显著高于湿地–农田过渡带和自然农田土壤显著(P<0.05)。0–40 cm土层中湖泊湿地和湿地–农田过渡带土壤有机碳各组分中总有机碳、易氧化有机碳和可溶性有机碳含量随土壤深度的增加而降低,而盐碱湿地土壤可溶性有机碳变化趋势则相反;农田土壤活性有机碳含量随土壤深度的增加无明显变化。柴窝堡湿地5种土地利用方式下土壤有机碳密度均高于全国平均值。pH与土壤有机碳的累积极显著负相关(P<0.01),电导率与土壤有机碳含量和易氧化有机碳含量极显著正相关(P<0.01)。自然农田或湿地垦殖后的农田土壤活性有机碳均高于湿地土壤。该研究结果说明土地利用方式影响了干旱区湿地土壤中有机碳的积累,对土壤活性有机碳组分影响显著。
Wetlands is important for the carbon balance of the arid area ecosystem to clarify the characteristics and influencing factors of active organic carbon in wetland soil.In order to investigate the influence of land use type on total soil organic carbon contents,soil organic carbon(SOC),readily organic carbon(ROC),and dissolved organic carbon(DOC)contents,as well as the organic carbon density,of Chaiwopu Lake wetland soil were determined.Land use type affected SOC content,as follows:farmland reclaimed before 1983[(22.97±0.85)g·kg^–1]>natural farmland[(21.83±1.97)g·kg^–1]>wetland farm belt[(16.74±6.52)g·kg^–1]>lake wetland[(11.98±3.67)g·kg^–1]>salinized wetland[(9.86±3.31)g·kg^–1].There was a significant difference in ROC content between wetland and farmland(P < 0.05).Furthermore, the DOCcontents of the farmland (reclaimed after 1983) soil was highest and significantly different (P < 0.05)from that of wetlandfarmlandtransition zone and natural farmland soils respectively. The SOC, ROC, and DOC contents decreased withincreasing depth (0 – 40 cm) in the lake wetland and wetland-farmland transition zone soils, whereas the opposite trend wasobserved for the DOC of the salinized wetland soil. The active organic carbon contents of farmland soil did not changesignificantly with increasing soil depth. The organic carbon density of Chaiwopu Lake wetland soil under five different landuse types was higher than the national average. Soil pH was negatively correlated with organic carbon accumulation (P <0.01), and soil conductivity was positively correlated with both SOC and ROC contents (P < 0.01). These results revealedthat the active organic carbon components of arid-area wetland soil are affected by land use type and that the active organiccarbon content of farmland soil after natural or wetland transformation is higher than that of wetland soil.
作者
龚月月
朱新萍
李典鹏
郑梦竹
杜婕
孙涛
GONG Yueyue;ZHU Xinping;LI Dianpeng;ZHENG Mengzhu;DU Jie;SUN Tao(College of Grassland and Environment Sciences,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China)
出处
《草业科学》
CAS
CSCD
2019年第8期1944-1952,共9页
Pratacultural Science
基金
国家自然科学基金(41305136)
新疆农业大学大学生创新项目(dxscx2017086)
关键词
湿地土壤
有机碳
易氧化有机碳
可溶性有机碳
wetland soil
organic carbon
readily organic carbon
dissolved organic carbon
