机构地区:[1]闽江学院海洋学院地理科学系,福州350108 [2]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福州350007
出 处:《生态学报》2018年第13期4861-4868,共8页Acta Ecologica Sinica
基 金:国家自然科学基金项目(31470501;31370465);"973"前期项目(2012CB722203);福建省高等学校新世纪优秀人才支持计划(2015)
摘 要:为了研究红壤侵蚀区生态恢复过程中土壤有机碳的组成与动态变化,选择红壤侵蚀区生态恢复10 a和30 a的马尾松林为对象,以侵蚀裸地和次生林为对照,应用土壤有机碳物理分组方法,研究了侵蚀地植被恢复过程中表层土壤粗颗粒态有机碳(cPOC)、细颗粒态有机碳(f POC)和矿质结合有机碳(MOC)含量及POC/MOC比值的变化。结果表明:生态恢复显著提高了土壤有机碳含量(P<0.05),土壤中不同组分有机碳含量也相应增加。生态恢复10 a,土壤有机碳主要以f POC形式积累,cPOC和MOC没有显著变化,其中0—10 cm土层POC占总土壤有机碳(SOC)比例高达64.1%,但稳定性较差。与恢复10 a相比,生态恢复至30 a时,0—10 cm土壤f POC含量相对不变,cPOC和MOC含量均显著增加(P<0.05),10—20 cm土壤f POC和MOC增加量达到显著水平,而cPOC含量仍未显著增加,说明生态恢复过程中土壤固碳模式符合SOC饱和理论。生态恢复过程中土壤POC/MOC比值呈先升高后降低的趋势,且表层土壤大于亚表层土壤,说明随着生态恢复时间的增加,土壤有机碳稳定性逐渐提高,且亚表层土壤高于表层。因此,生态恢复对于侵蚀地碳固定的长期有效性具有重要意义。Composition and dynamics of soil organic carbon (SOC) are important indicators for soil restoration. However, little attention has been paid to SOC dynamics in red soil erosion areas. We conducted an investigation in the surface soil layers (0-10 and 10-20 cm) in Pinus massoniana woodlands with restoration histories of 10 and 30 years respectively. We studied the changes of the contents of soil organic carbon (SOC) fractions, coarse particulate organic carbon (cPOC), fine particulate organic carbon (fPOC), and mineral-associated organic carbon (MOC), as well as the POC/MOC ratios, to determine the effects of ecological restoration in both woodlands compared to bare land and secondary forest. Our results showed that the various types of soil organic carbon in both soil layers significantly increased with time of restoration (P 〈 0.05). In the stand with 10 years restoration, the soil fPOC increased significantly in the top soil (0-10 cm) which accounted for more than 64.1% of the total SOC content, indicating that the SOC mostly accumulated in the form of fPOC. However, the soil cPOC and MOC had no significant changes. Compared to the stand with 10 years of restoration, in the Pinus massoniana woodland with 30 years of restoration, the soil cPOC and MOC increased significantly in the top layer (〈 10 cm), but fPOC did not. The contents of fPOC and MOC also increased significantly in the 10-20 cm layer, but the cPOC contents did not. The results demonstrated that the patterns of SOC sequestration in the process of ecological restoration confirmed the SOC saturation theory. The soil POC/MOC ratio was higher in the top layer than in the deeper layer and initially increased with time of restoration, reaching its highest value in our study in the 10-year stand, then decreased rapidly. The results indicated that the SOC became more stable in subsoil than in topsoil with restoration time, which highlighted that ecological restoration plays a crucial role in long-term sequestration o
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