不同管理模式下工苜蓿地固碳效应分析.pdf

人工草地在退耕 2a-10a 间的固碳速率已由退耕初期的 0.05 kg m-2 a-1 上升到 0.52 kg m-2 a-1 ，退耕 10a-30a 间固碳速率虽有下降但仍高于退耕初期。利用表征土壤结构的重 要指标之一土壤容重与人工草地总有机碳储量进行相关分析得出其与人工草地总有机 2 碳储量存在极显著的线性负相关，R =0.943 。另外，其他种群的出现、群落的演替和群 落结构的改变导致的植被生物量的变化对人工草地总有机碳储量具有重要影响。 关 键 词：紫花苜蓿；人工草地；管理模式；碳储量；固碳速率；影响因素 论文类型：理论研究 Subject : Research on Carbon Sequestration Effect of Alfalfa Grassland in Different Management Modes Specialty : Environmental Science Name : Shao Chuan-ke （Signature ） Instructor : Zhao Xiao-guang （Signature） ABSTRACT Alfalfa artificial grassland in loess hilly and gully regions of southern ningxia was studied in a space series of replaced time courses. With the management mode of mowing in the earlier years and abandonment in the later years, the variation of vegetation and soil carbon storage and rate in different restoration years were studied. 1、 During 2a-30a,the alfalfa was still the dominant of the artificial grassland.The importance value of alfalfa decreased from 97.33 to 22.20 with the increase of restoration years.The Margalef, Alatalo and Shannon-Wiener index increased by 1.22,1.55 and 0.40 respectively and the simpson index decreased by 0.70. 2 、 With the change of management mode, the organic content, total nitrogen content and phosphorus content declined first and then rose.The changing trend of soil volume weight showed in opposite direction.It changed in 2a in the trends of all of them.Both soil organic content and total nitrogen content reached maximum in the 0 -10cm layer. 3 、 Both of the above