不同龄组人工林土壤团聚体结构状况——以杉木、鹅掌楸为例毕业论文

 2021-04-20 09:04

摘 要

土壤团聚体结构状况作为土壤优劣指标,也是土壤肥力的重要指标之一,对林业生产具有重要影响。杉木、鹅掌楸作为重要的人工林栽培树种,对其人工林土壤团聚体结构状况的深入研究,对改善人工林土壤肥力具有重要意义。为分析比较不同龄组人工林土壤团聚体的结构状况,获得较可靠的土壤团聚体状况指标与研究方法,分别揭示了不同龄组人工林的土壤质量。以福建洋口国际林场不同龄组的杉木、鹅掌楸人工林为研究对象,采用湿筛法测定土壤团聚体的组成,研究不同龄组人工林土壤团聚体的结构状况。结果表明:

  1. 杉木与鹅掌楸人工林内gt;0.25mm的大团聚体含量由大到小分别是成熟林、幼龄林、中龄林。
  2. 杉木人工林较鹅掌楸人工林不同龄组间团聚体分布波动较为平稳,其团聚体分布差异较小。随着土层的加深,杉木人工林土壤大团聚体的比例在幼、中龄木人工林中均出现先减后增的趋势,而在成熟林内则出现小幅度先增后减的波动。
  3. 鹅掌楸人工林大团聚体在不同林龄土壤中的比例却各不相同,幼龄林内出现逐渐增加的趋势,中龄林内出现先减后增的趋势,成熟林内波动较低,中层土内含量略高于浅层土和深层土。
  4. 不同林龄与土层深度均对人工林土壤团聚体的稳定性有显著影响。

关键词:人工林;团聚体;林龄

Soil Aggregate Structure of Different Age Groups of Plantations: A Case Study of Chinese Fir and Liriodendron

ABSTRACT

The soil aggregate structure status is an indicator of soil quality and is also an important indicator of soil fertility, which has an important impact on forestry production.Cunninghamia lanceolata and Liriodendron chinense are important plantation species, and the in-depth study on the soil aggregate structure of artificial forests is of great significance for improving the soil fertility of artificial forests. In order to analyze and compare the structural status of soil aggregates in different age groups, the soil aggregates status indicators and research methods were obtained, and the soil quality of different age groups was revealed. Taking the Cunninghamia lanceolata and Liriodendron chinense plantations in different age groups of Fujian Yangkou International Forest Farm as the research object, the composition of soil aggregates was determined by wet sieve method, and the structure of soil aggregates in different age groups was studied. The results show:

(1) The content of large aggregates gt;0.25mm in Cunninghamia lanceolata and Liriodendron chinense plantations is mature forest, young forest and middle-aged forest.

(2) The distribution of aggregates in different age groups of Cunninghamia lanceolata plantations was relatively stable, and the distribution of aggregates was small. With the deepening of the soil layer, the proportion of large aggregates in the soil of Cunninghamia lanceolata plantation decreased firstly and then increased in the young and middle-aged wood plantations, while in the mature forest, there was a small increase and then decrease.

(3) The proportion of large aggregates of Liriodendron chinense plantation in different soil ages is different. The young forests tend to increase gradually, and the middle-aged forests tend to decrease first and then increase, and the mature forests have low fluctuations. The content of the middle layer soil is slightly higher than that of the shallow soil and the deep soil.

(4) Different forest ages and soil depths have significant effects on the stability of soil aggregates in plantations.

Keywords:plantation;aggregate;stand age

目录

摘 要 I

1 绪论 1

1.1 研究目的和意义 1

1.2 国内外研究进展 1

1.2.1 土壤团聚体的形成及稳定性 1

1.2.1.1 土壤团聚体的形成 1

1.2.1.2 土壤团聚体的稳定性 3

1.2.2 林业土壤团聚体的组成及变化规律 4

1.2.2.1 天然林土壤团聚体的组成及变化规律 5

1.2.2.2 人工林土壤团聚体的组成及变化规律 5

1.2.3 林业土壤团聚体的影响因素 7

1.2.3.1 林木对土壤团聚体的影响 7

1.2.3.2 经营年限对土壤团聚体的影响 8

1.3 研究内容与技术路线 11

1.3.1 研究内容 11

1.3.2 技术路线 11

2 研究地概况与研究方法 12

2.1 研究地概况 12

2.2 研究方法 12

2.2.1 样地选择 12

2.2.2 土壤样品采集与处理 13

2.2.3 土壤团聚体分级及其有机碳测定方法 13

2.2.4 数据处理 13

3 结果分析 13

3.1 不同龄组杉木人工林土壤团聚体结构状况 14

3.1.1 杉木人工林土壤各粒级团聚体含量 14

3.1.2 杉木人工林土壤团聚体(gt;0.25mm)含量 15

3.2 不同龄组鹅掌楸人工林土壤团聚体结构状况 16

3.2.1 鹅掌楸人工林土壤各粒级团聚体含量 16

3.2.2 鹅掌楸人工林土壤团聚体(gt;0.25mm)含量 17

3.3 杉木、鹅掌楸人工林 0-60cm 土壤团聚体结构总体状况 18

4 结论与讨论 19

致谢 20

参考文献 21

不同龄组人工林土壤团聚体结构状况

——以杉木、鹅掌楸为例

1 绪论

1.1 研究目的和意义

土壤团聚体是土壤功能的基本单位,团聚体结构状况不仅直接影响土壤孔隙性、持水性、通气性,而且还会影响土壤抗蚀性及水土保持性能。已有研究表明,土壤团聚体结构状况受土壤种类、土层位置、植被、利用状况及利用时间等多种因素的影响,因此,通过野外调查、采样和室内分析,研究不同龄组人工林土壤团聚体结构状况,对科学经营人工林、改善土壤结构和提高水土保持性能都具重要意义。

1.2 国内外研究进展

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