| 摘要: |
| 【目的】对云南省玉溪市磨盘山云南松天然次生林5种营养元素(N、P、K、Ca、Mg)的含量、积累、分配及其随林龄变化的趋势进行研究，为云南松林养分利用及森林生态服务功能价值核算提供基础数据。【方法】选取15，30和45年生云南松天然次生林为研究对象，在各林龄林地中各设置3个20 m×20 m的标准样地，对样地内的乔木层按照叶、枝、干、根取样，灌木分叶、枝、根取样，草本分地上部分和地下部分取样，凋落物全部取样，同种植物的相同器官取混合样品，所有样品取回后在实验室进行生物量和营养元素含量的测定与分析。【结果】云南松不同器官营养元素含量大小次序为树叶＞树枝＞树根＞树干；各器官营养元素含量均以N最高，其次是K和Ca，Mg、P较低。15，30和45年生云南松天然次生林营养元素积累总量分别为192.00，930.95和2 357.36 kg/hm2，其中乔木层营养元素积累量所占比例依次为70.70%，66.84%和98.82%，林下植被层所占比例依次为22.97%，7.53%，0.43%，地表现存凋落物所占比例依次为7.0%，26.98%和0.80%。乔木层、林下植被层和凋落物层均以N积累量最多，P最少。云南松N与P含量比随着林龄的增长呈下降趋势，15，30和45年生云南松天然次生林每积累1 t干物质需要5种营养元素的总量分别为8.38，8.52和7.68 kg，其中对N的利用效率最低，P最高。【结论】不同林龄云南松对营养元素的利用效率均较高，所以从营养元素利用效率来分析，云南松林不会因过度消耗土壤中的营养元素而导致土壤肥力降低，说明云南松有耐贫瘠、适应性强、适合荒山造林等特点。 |
| 关键词: 云南松 天然次生林 营养元素 积累与分配 |
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| 基金项目:国家林业局林业公益性行业科研专项（201204101-10） |
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| Accumulation and distribution characteristics of nutrients in Pinus yunnanensis forests with different ages |
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TONG Zhi-long,CHEN Qi-bo,WANG Yan-xia,et al
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| Abstract: |
| 【Objective】 The content,accumulation,distribution and their changing trends along with forest stand age of five nutrient elements (N,P,K,Ca,and Mg) in natural secondary Pinus yunnanensis forest in Mopan mountain,Yuxi City,Yunnan Province were studied,to improve nutrient utilization and estimation of forest ecological value.【Method】 Natural secondary Pinus yunnanensis forests with ages of 15,30 and 45 years were selected,and three 20 m×20 m standard samples were set in each forest.Samples were collected from leaves,branches,stems,and roots of arbor layer plants,leaves,twigs,and roots of shrubs,aboveground and underground parts of herbs,and all parts of litter in each sample plot.Biomass and nutrient elements of mixed samples from same organs of same plants were analyzed in laboratory.【Result】The contents of nutrition element in Pinus yunnanensis were in a decreasing order of leaves＞branches＞roots＞trunk.N was the nutrient element with highest content,followed by K and Ca,Mg and P had the lowest contents.The accumulations of total nutrient elements of 15,30 and 45-year-old natural secondary Pinus yunnanensis forests were 192.00,930.95 and 2 357.36 kg/hm2,respectively.Arbor layer accounted for 70.70%,66.84%,and 98.82%,understory vegetation layer accounted for 22.97%,7.53%,and 0.43%,and litter layer accounted for 7.0%,26.98% and 0.80%,respectively.N had the largest accumulation among all layers,while P was the lowest.The ratio of nitrogen content to phosphorus content decreased as the increase of forest age.The total of the five nutrient elements needed for accumulation of 1 t dry matter for Pinus yunnanensis with age of 15,30,and 45 years were 8.38,8.52 and 7.68 kg,respectively.The use efficiency of N was the least while that of P was the highest.【Conclusion】 Pinus yunnanensis had high nutrient use efficiency,and it would not result in decrease of soil fertility due to excessive consumption of nutrient elements in the soil.Pinus yunnanensis has high resistance and good adaptability,and is suitable for afforestation in barren hills. |
| Key words: Pinus yunnanensis natural secondary forest nutrient elements accumulation and distribution |
