摘要: |
【目的】研究增加降水对四川干旱河谷区云南松(Pinus yunnanensis)人工林凋落叶分解的影响。【方法】2013年3月至2014年3月,采用尼龙网袋法,设置增加降水10%(A1,80 mm/(m2·a))、增加降水20%(A2,160 mm/(m2·a))、增加降水30%(A3,240 mm/(m2·a))和对照(CK,0 mm/(m2·a))4个处理。通过原位试验研究了四川干旱河谷区云南松人工林凋落叶在不同增加降水处理下的分解动态。【结果】分解1年后,A1、A2、A3处理云南松凋落叶的质量残留率分别较CK降低了8.70%,6.40%和4.60%,凋落叶的分解速率表现为A1>A2>A3>CK;与CK相比,A1处理促进了N元素的释放,A3处理促进了N元素的富集;各增加降水处理均促进了P元素的释放,其中A3处理的促进作用最强;增加降水促进了凋落叶木质素的降解,降低了凋落叶C/N和木质素/N,而凋落叶C/P随降水增加表现为先减小后增大的趋势。【结论】增加降水促进了干旱河谷区云南松人工林凋落叶的分解,但促进作用并不随降水量的增加而增强。 |
关键词: 降水量 云南松人工林 凋落叶分解 |
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基金项目:国家“十二五”科技支撑计划项目(2010BACO1A11) |
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Effects of increasing precipitation on leaf litter decomposition in Pinus yunnanensis plantation in Sichuan dry river valley |
LIU Wei,WANG Lihua,LIU Lin,et al
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Abstract: |
【Objective】The study investigated the effects of increasing precipitation on leaf litter decomposition in Pinus yunnanensis plantation in Sichuan dry river valley area.【Method】Litter-bag method was used to investigate leaf decomposition of P.yunnanensis in the arid valley area in Sichuan with four treatments including CK (natural state,0 mm/(m2·a)),A1 (increasing precipitation by 10%,80 mm/(m2·a)),A2 (increasing precipitation by 20%,160 mm/(m2·a)) and A3 (increasing precipitation by 30%,240 mm/(m2·a)).The research was conducted during March 2013 to March 2014.【Result】After one year decomposition, the mass residual ratios of A1,A2 and A3 were reduced by 8.70%,6.40% and 4.60% compared with CK,and decomposition rates were in the order of A1>A2>A3>CK.A1 promoted the release of N,and A3 promoted the enrichment of N.All treatments promoted the release of P,and A3 was the best.Increasing precipitation significantly inhibited the enrichment of lignin,reduced C/N and lignin/N,and C/P decreased firstly before increasing.【Conclusion】Leaf litter decomposition was promoted by increasing precipitation in P.yunnanensis plantation in Sichuan dry river valley area,but the effect didn’t enhance with increase of precipitation. |
Key words: precipitation Pinus yunnanensis plantation leaf litter decomposition |