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应用生态学报 ›› 2011, Vol. 22 ›› Issue (06): 1389-1394.

• 研究报告 • 上一篇    下一篇

干旱区人工防护林带不同林分凋落叶分解及养分释放

杨玉海1,2,郑路3**,段永照4   

  1. 1荒漠与绿洲生态国家重点实验室, 乌鲁木齐 830011; 2中国科学院新疆生态与地理研究所, 乌鲁木齐 830011; 3中国林业科学研究院热带林业实验中心, 广西凭祥 532600; 4新疆农业职业技术学院, 新疆昌吉 831100
  • 出版日期:2011-06-18 发布日期:2011-06-18

Leaf litter decomposition and nutrient release of different stand types in a shelter belt in Xinjiang arid area.

YANG Yu-hai1,2, ZHENG Lu3, DUAN Yong-zhao4   

  1. 1State Key Laboratory of Desert and Oasis Ecology, Urumqi 830011, China;2Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; 3Experimental Centre of Tropical Forestry, Chinese Academy of Forestry, Pingxiang 532600, Guangxi, China;4Xinjiang Agricultural Vocational Technical College, Changji 831100, Xinjiang, China
  • Online:2011-06-18 Published:2011-06-18

摘要: 2007年10月下旬至2008年11月,采用原位模拟分解网袋法,对新疆克拉玛依市区北郊人工防护林新疆杨、紫穗槐及二者混合凋落叶进行为期365 d的分解及养分释放动态试验.结果表明:树种不同,凋落叶质量损失率的动态变化不同;凋落叶组成对质量损失率有显著影响,与单优林凋落叶相比,紫穗槐与新疆杨凋落叶混合后更易于分解.经修正Olson负指数衰减模型分析,新疆杨凋落叶分解系数最低(k=0.167),混合凋落叶分解系数最高(k=0.275),估测3种凋落叶半分解和95%分解所需时间为2.41~4.19 a和10.79~17.98 a.不同的分解时期3种凋落叶中N、P和K的残留率不同,分解1年后,K为净释放,N和P为固持或从周围环境中吸收而富集.分解过程中,除紫穗槐凋落叶在分解中期有机碳分解率下降外,其他处理凋落叶有机碳分解率均不断上升,1年后分解率在35.5%~44.2%之间.C/N值基本呈下降趋势,分解前期和中期下降幅度较小,后期下降较快.

关键词: 凋落叶, 分解, 养分释放

Abstract: From October 2007 to November 2008, an in situ mesh bag experiment was conducted to study the leaf litter decomposition and nutrient release of forest stands Populus alba var. pyramidalis, Amorpha fruticosa, and P. alba  var. pyramidalis + A. fruticosa in a shelter belt in Karamay, Xinjiang. It was observed that the mass loss rate of leaf litter differed with tree species, and was significantly affected by leaf litter composition. The leaf litter of P. alba var. pyramidalis + A. fruticosa was more easily decomposed than that of the other two mono-dominance forest trees. The analysis with improved Olson’s exponential model indicated that P. alba var. pyramidalis leaf litter had the lowest decomposition coefficient (k=0.167), while P. alba var. pyramidalis + A. fruticosa leaf litter had the highest one (k=0.275). According to the model, it would cost for about 2.41-4.19 years and 10.79-17.98 years to have 50% and 95% decomposition of the three kind leaf litters, respectively. The residual rates of nitrogen, phosphorus, and potassium in the three kind leaf litters differed with decomposition period. After one year decomposition, potassium was wholly released, while nitrogen and phosphorus were immobilized or enriched via the absorption from surrounding environment. Except that the A. fruticosa leaf litter had a decreased organic carbon decomposition rate in the mid period of decomposition, the leaf litters of P. alba var. pyramidalis and P. alba var. pyramidalis + A. fruticosa all had an increasing organic carbon decomposition rate with the decomposition, which was about 35.5%-44.2% after one year decomposition. The C/N value of the leaf litters had a decreasing trend, and the decrement was smaller in the early and mid periods but larger in the late period of decomposition.

Key words: leaf litter, decomposition, nutrient release