四川农业大学学报

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华西雨屏区巨桉人工林凋落物数量及其分解特征

胡庭兴   

  1. 四川农业大学林学院
  • 收稿日期:2011-03-21 修回日期:2011-12-12 出版日期:2011-12-25 发布日期:2011-12-26
  • 通讯作者: 胡庭兴

Study on the Characteristics of Litter Production and Decomposition in plantations of Eucalyptus grandis in Rainy Area of West China

Hu TingXing   

  1. College of Forestry, Sichuan Agricultural University
  • Received:2011-03-21 Revised:2011-12-12 Online:2011-12-25 Published:2011-12-26
  • Contact: Hu TingXing

摘要:

摘要:通过原位试验,研究了华西雨屏区巨桉(Eucalyptus grandis)林凋落量、凋落物分解以及养分释放特征。结果表明:⑴ 华西雨屏区巨桉人工林的年凋落量为6247.78 kg?hm-2;凋落叶是凋落物中的主要组分,占全年凋落量的94.85%;凋落物各组分间凋落量大小顺序表现为:凋落叶>凋落枝>凋落皮。⑵ 在不同组分凋落物分解过程中,叶的分解速率比枝条快,分解12个月后,叶的质量残留率为39.56%,枝条的质量残留率为56.35%;叶在分解的5~8月时分解速率较大,而枝则在第4~10月时分解率较大;凋落叶分解95%需要2.989 a,枝条分解95%需要4.783 a。⑶ 经12个月的分解,凋落叶各养分元素年释放速率大小表现为:N>C>P>K;凋落枝各养分元素释放速率大小表现为:C>N>K>P;凋落叶各养分元素释放速率均高于凋落枝;⑷ 凋落叶、凋落枝初始C/N分别为43.51、285.78;在分解过程中,各密度凋落叶、凋落枝C/N比变化动态总体均表现为下降趋势。

关键词: 凋落物分解, 养分释放, 巨桉林, 华西雨屏区

Abstract:

Abstract: An in situ experiment was conducted in Eucalyptus grandis plantation in Rainy Area of West China to study litter production, litter decomposition and litter nutrient release. The results were given as follows: ⑴ The stands give the annual litter production of 6247.78 kg?hm-2. Leaf litter is main component, and account for 94.85%, The amount of litter components of different density stands was leaf>twig>bark.⑵ The leaf and twig litter had different decomposition rates, and the higher one was leaf litter. After decomposing for 12 months, the stands remained litter mass rate of leaf was 39.56%, and the remained litter mass rate of twig was 56.35%, Leaf litter had a faster decomposition speed during the 5th month to the 8th month, while the decomposing rate of twig was faster from the 4th month to the 10th month. It would take 2.989 a for 95% of leaf litter to decompose and 4.783 a for twig litter. ⑶ After decomposing for 12 months, the four nutrient elements could be arranged with respect to nutrient release rate in this sequence: (leaf) N>C>P>K, (twig)C>N>K>P. All nutrient release rates in leaf litter were higher than those in twig litter in the stands.⑷ The initial C/N ratios in leaf and twig litters were 43.51 and 285.78.In the decomposing process of litter and twig, the C/N had an decreasing trend.

Key words: litter decomposition, Nutrient Release, Eucalyptus grandis, Rainy Area of West China