抚育间伐对马尾松人工林氮形态的影响毕业论文_生态学毕业论文

抚育间伐对马尾松人工林氮形态的影响毕业论文

2021-04-27更新

摘 要

本文以南京市溧水林场实施间伐10年的30年生马尾松(Pinus massoniana Lamb.)人工林为研究对象,以实施封山育林的30年生马尾松(Pinus massoniana Lamb)人工林为对照。通过两块样地研究间伐对马尾松人工林土壤各形态氮的含量的影响,同时研究其他因素与土壤氮的关系。以期找出科学的经营措施提高土壤氮的含量,提高土壤肥力,为提高森林质量提供科学依据。结果表明:

  1. 实施间伐后的马尾松人工林在土壤表层(0-10cm)的总氮含量为0.216g/kg,相比较未间伐增长了23.4%,实施间伐后的马尾松人工林在土壤亚表层(10-20cm)的总氮含量为0.147g/kg,相比较未间伐增长了24.6%,总体而言实施间伐后的马尾松林的总氮含量是呈现增长趋势的。
  2. 实施间伐后的马尾松人工林土壤表层(0-10cm)的氨态氮含量是2.847mg/kg,相比较未间伐增长了40.1%,实施间伐后的马尾松人工林土壤亚表层(10-20cm)的氨态氮含量是3.025mg/kg,相比较未间伐增长了80.9%;实施间伐的马尾松人工林土壤表层(0-10cm)的硝态氮含量是5.653mg/kg,相比较未间伐降低了了65.1%,土壤亚表层(10-20cm)的硝态氮含量是3.981mg/kg,相比较未间伐降低了61.0%。

(3)实施间伐的马尾松人工林土壤表层(0-10cm)的可溶性有机氮含量是17.719mg/kg,相比较未间伐增长了8.0%;实施间伐的马尾松人工林土壤亚表层(10-20cm)的可溶性有机氮含量是3.778mg/kg相比较未间伐增长了31.7%。

关键词:马尾松人工林,土壤氮,间伐,封山育林

The effect of thinning tending measures on Nitrogen forms in Pinus massoniana Lamb Plantation

Abstract

   In this thesis,an experiment was conducted to find out the effects of thinning tending measure on the content of different forms of soil nitrogen and the influence caused by other factors on the soil nitrogen in two sample plots with the same site condition.The sample plot is a 30-year-old Pinus massoniana Lamb. plantations in LiShui , one of them was thinned in 2004 the other have no measure being taken . So as to find out the scientific management measures in order to increase the content of soil nitrogen ,to improve the soil fertility and to provide a scientific basis for improving the forest quality.Study has shown that:
   After thinning the content of total soil nitrogen were 0.216g/kg at the 0-10cm soil layer and increased by 23.4% compared with the control plot;at the 10-20 cm layer it was 0.147g/kg, increased by 24.6% compared with the control plot.The content of total soil nitrogen has the trend of increasing.
    Thinning increased the content of ammoniacal nitrogen and reduced the content of the soil nitrate nitrogen. The content of soil ammoniacal nitrogen in the 0-10cm, 10-20cm soil layer in the thinning sample plot is 2.847mg/kg and 3.025mg/kg, which were 40.1% and 80.9% higher than the blank control. On the contrary, the content of soil nitrate nitrogen in 0-10cm and 10-20cm soil layer is 5.653mg/kg and 3.981mg/kg which reduced by 65.1% and 61.0%.
   Thinning obviously increased the content of soil soluble nitrogen. In 0-10cm and 10-20cm soil layer in the sample plot, the soluble nitrogen were 17.719mg/kg and 3.778mg/kg which is 8.0% and 31.7% higher than the blank control sample plot.

Keywords: Pinus massoniana Lamb. Plantations, soil nitrogen, Thinning , close hillsides to facilitate afforestation

目 录

1 绪论……………………………………………………………………………………………………………1

1.1选题依据及研究意义……………………………………………………………………………………1

1.2森林土壤氮形态国内外研究状况……..…………………………………………………………1

1 . 2 . 1森林土壤氮素的形态……………………………………………………….………………………2

1 . 2 . 2森林土壤氮素对干扰的响应……………………………….………………..…………….…..2

1 . 2 . 3森林土壤氮素对抚育间伐的响应………………………….…………………..…….………..3

2 研究区概况和研究方法 ……………………………………………………………………………4

2.1研究区概况……………………………………………………………..…………………………………4

2 . 1 .1研究区概况…………………………..………………………………………………………………4

2 . 1 . 2 林分概况………………………………………..……………………….…………..……………4

2 . 1 . 3 样地设置……………………………………………..………………………………..…………5

2.2研究方法……………………………………………………………….…………………………………5

2 . 2 .1样品采集和处理…………………………………………..………………..………6

2 . 2 . 2 测定方法…………………………………………..…………………………………………….………6

2 . 2 . 3 数据分析…………………………………………..…………………………………………….………7

2 .3 技术路线……………………..………………………………..………………………………………………………7

3 研究结果…………………………………………………………………….………………………………8

3 .1 间伐对土壤氮含量的影响……………………………………………..………………………………….8

3 .2 间伐对马尾松林下土壤中硝态氮、氨态氮的影响…………………..…………….……………………8

3 .3间伐对土壤中可溶性有机氮的影响………………………………..…………..………..…………………9

4 分析与讨论…………………………………………………………………………..……………….….……11

…………………………………………………………………………………………………………………….

致谢………………………………………………………………………………………….………………………13

参考文献………………………………………………………………….……………………………………………………14

1绪论

选题依据及研究意义

氮素是生态系统中最多的元素,同时是植物个体乃至自然生态系统和人工生态系统中作物生长的限制因子。森林生态系统土壤氮储量占整个生态系统氮储量的90%-95%。作为全球氮库的主体,森林生态系统土壤氮库的微小变化,可能导致大气中N2O的浓度发生较大变化,以致影响全球气候变化。森林生态系统作为制约土壤氮库的重要因素已经成为世界各国调控平衡土壤氮库的最主要途径。

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