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植物研究 ›› 2017, Vol. 37 ›› Issue (3): 360-369.doi: 10.7525/j.issn.1673-5102.2017.03.006

• 研究报告 • 上一篇    下一篇

降水强度变化对天山云杉地表凋落物和细根分解的影响

李吉玫, 张毓涛, 李翔, 韩燕梁   

  1. 新疆林业科学院森林生态研究所, 乌鲁木齐 830063
  • 收稿日期:2016-12-07 出版日期:2017-05-15 发布日期:2017-06-03
  • 作者简介:李吉玫(1980-),女,副研究员,从事干旱区森林生态研究。
  • 基金资助:
    新疆维吾尔自治区自然科学基金(2016D01A008)

Impact of Precipitation Intensity on the Decomposition of Floor Litter and the Fine Roots of Picea schrenkiana

LI Ji-Mei, ZHANG Yu-Yao, LI Xiang, HAN Yan-Liang   

  1. Institute of Forest Ecology, Xinjiang Academy of Forestry, Urumqi 830063
  • Received:2016-12-07 Online:2017-05-15 Published:2017-06-03
  • Supported by:
    Natural Science Foundation of the XinJiang Uygur(2016D01A008)

摘要: 为了探明不同降水条件下干旱区山地森林主要优势树种凋落物分解特征,采用野外模拟试验,通过设计3种降水强度处理[ZP(去除降水)、CK(自然降水,对照)、DP(双倍降水)],研究了降水强度变化对天山云杉地表凋落物(叶和枝)和细根分解的影响。研究结果表明:分解24个月后对照凋落叶、凋落枝和细根干重损失率比去除降水损失率分别高24.79%、2.54%和23.09%,比双倍降水损失率低7.04%、0.68%和10.70%,去除降水对凋落叶和细根分解的抑制作用显著,对凋落枝抑制作用较微弱,双倍降水对分解具有促进作用,但仅对细根分解的促进作用显著。对照和双倍降水处理下凋落叶和细根月平均分解率均表现为双峰型曲线,凋落枝为单峰曲线,去除降水处理下地表凋落物和细根月平均分解率相对平缓。木质素和纤维素残留率也表现为去除降水 > 对照 > 双倍降水。不同降水处理下分解过程中N元素释放模式不同,但C释放模式基本一致。相关分析表明,凋落物月分解率与0~10 cm土层温度的相关性不显著(P>0.05),但与土壤含水量间为线性极显著正相关(P<0.05)。我们研究结果发现云杉凋落物与根系分解对降水强度变化存在明显差异,未来气候变化对土壤碳周转影响应该充分考虑这种器官间差异。

关键词: 降水强度, 凋落物, 分解, 养分释放, 天山云杉, 干旱区山地森林

Abstract: To study the characteristics of litter decomposition of the dominant tree species of mountain forests in arid areas under different precipitation conditions, a field simulation experiment was performed with three precipitation treatments of ZP(zero precipitation), CK(natural precipitation), and DP(double precipitation). The impact of precipitation intensity on the decomposition of litter(leaves and branches) and the fine roots of Picea schrenkiana was investigated. Compared with decomposition rates of leaf, branch and fine root under CK treatment, those of under ZP treatment were 24.79%,2.54% and 23.09% lower, whereas, those of under DP treatment were 7.04%, 0.68% and 10.70% higher, respectively. ZP treatment significantly inhibited the decomposition of leaf litters and fine roots(P<0.05) and weakly inhibited the decomposition of branch litters(P>0.05). DP treatment only significantly promoted the decomposition of fine roots(P<0.05). For the CK and DP treatments, the monthly average decomposition rates of leaf litters and fine roots and branch litters showed single-peak curves, respectively, whereas the monthly average decomposition rates of litters and fine roots were relatively stable for ZP treatment. The remaining rates of the lignin and cellulose from different organs showed that ZP>CK>DP. With the different precipitation treatments, the release patterns of N were different, whereas the release patterns of C were essentially the same. By correlation analysis, the monthly decomposition rate of litter was not significantly correlated with soil temperature at depths in 0 10 cm(P>0.05) but showed a significant positive linear correlation with the soil water content(P<0.05). Our findings highlight that future climatic change effects should fully consider the organ-dependent differences of litter and root decomposition in arid mountain forests.

Key words: precipitation intensity, litter, decomposition, nutrient release, Picea schrenkiana var. tianshanica, arid mountain forest

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