黄土高原人工苜蓿草地固碳效应评估  

Evaluation on carbon sequestration effects of artificial alfalfa pastures in the Loess Plateau area

作　　者：李文静[1,2] 王振[1,2] 韩清芳[1,2] 任曾辉 闫明科 张鹏[1] 贾志宽[1,2] 杨宝平[1,2] 

机构地区：[1]西北农林科技大学中国旱区节水农业研究院∕农业部西北黄土高原作物生理生态与耕作重点实验室,杨凌712100 [2]西北农林科技大学农学院,杨凌712100

出　　处：《生态学报》2013年第23期7467-7477,共11页Acta Ecologica Sinica

基　　金：国家"十二五"科技支撑计划资助项目(2012BAD09B09);高等学校学科创新引智计划资助项目(B12007);陕西科技创新资助项目(2010NKC-03;2011NXC01-16);西北农林科技大学基本科研业务费资助项目(CX200902)

摘　　要：苜蓿草地作为黄土高原草地的重要组成部分,在黄土高原草地生态系统碳循环中占有重要地位。同时由于苜蓿具有固氮和固碳的双重作用,使它在低碳农业的发展中具有重要意义。以1年生(建植初期)、3年生(盛产期)、5年生(稳产期)和10年生(衰败期)的人工苜蓿草地为研究对象,利用地上地下生物量和土壤碳贮量,定量分析了人工苜蓿草地不同发育阶段的固碳能力;结合种植面积,对黄土高原区人工苜蓿草地的总固碳效应进行了评价。研究结果表明:苜蓿草地地上生物固碳能力以3年生和5年生最强,并显著高于其他年限;地下生物固碳和土壤固碳量均以10a苜蓿草地最高,且显著高于其他年限。总体而言,人工苜蓿草地以土壤固碳为主,并集中在0—80cm土壤,各年限0—80cm土层土壤固碳量分别占到总固碳量的41.02%、39.43%、41.56%、39.59%;而地下生物固碳主要发生在0—20cm土层,各年限该层生物固碳量分别占到地下生物总固碳量的45.74%、55.68%、53.12%和43.28%。苜蓿草地在整个生命周期中总固碳量随生长年限逐年增长,但增长速度不明显,各年限单位面积总固碳量分别为12.69、13.49、13.31 kg/m2和14.83 kg/m2。估算得到黄土高原的人工苜蓿草地年总固碳量为1.430×1011kg(143.0 Tg),其中地上、地下、土壤分别为5.43、1.15Tg和136.4Tg。研究结果为正确分析区域碳循环和发展低碳大农业提供了重要理论参考。Carbon of grasslands is an important component in the global carbon cycle and often plays a dominant role in continental and regional carbon budgets. Identifying Carbon dynamics in grassland ecosystems is significant to predict the response of grassland ecosystems to future climate change. As the important component of the grasslands on Loess Plateau, alfalfa pastures which have both effects of nitrogen fixation and carbon sequestration, not only have great influences on the carbon cycle of the grasslands on Loess Plateau, but also play a significant role in low carbon agriculture. However, the carbon sequestration effects of alfalfa pastures on Loess Plateau are poorly understood. This research studied the carbonsequestration effects of alfalfa pastures which have grown one year（ initial stage of establishment）, three years（ high yielding period）, five years （stable production period） and ten years（ obviously decline phase）. With measuring the carbon content of the above-ground vegetation, below-ground vegetation, and soil, the research quantitatively analysed the carbon sequestration effects of alfalfa pastures with different planting ages, meanwhile, evaluated the carbon sequestration effects of the alfalfa pastures on Loess Plateau. The results showed that alfalfa pastures with the growth of 3 and 5 years owned the strongest ability of above-ground vegetation carbon sequestration, while the 10-year-old had the highest ability of carbon sequestration of both below-ground vegetation and soil. The soil carbon sequestration focused on 0--80cm soil layer, while the below-ground vegetation focused on 0--20cm. The soil carbon sequestration amount of 0--80 cm soil layer of different planting ages accounted for 41.02%, 39.43%, 41.56% and 39.59% of their total soil carbon sequestration amount respectively whilst the below-ground vegetation occupied 45.74%, 55.68%, 53.12% and 43.28% respectively. The total fixed carbon amounts of alfalfa pastures were growing with the increase of planting age, but the ra

关 键 词：黄土高原 人工苜蓿草地 发育阶段 固碳 空间特征 

分 类 号：S541.9[农业科学—作物学]