晋西黄土区退耕年限对土壤物理性质的影响

张恒硕; 查同刚; 张晓霞

doi:10.12171/j.1000-1522.20190087

晋西黄土区退耕年限对土壤物理性质的影响

张恒硕^1,,
查同刚^1,2,3, ,,
张晓霞^1,2

1.
北京林业大学水土保持学院，北京 100083
2.
水土保持国家林业和草原局重点实验室，北京 100083
3.
北京市水土保持工程技术研究中心，北京 100083

基金项目: 国家“十二五”科技支撑计划课题（2015BAD07B03）

详细信息

作者简介:
张恒硕。主要研究方向：土壤退化与生态修复。Email：zhs418473740@bjfu.edu.cn　地址：100083北京市海淀区清华东路35号北京林业大学水土保持学院

责任作者:
查同刚，博士，副教授。主要研究方向：土壤退化与生态修复。Email：zhtg73@bjfu.edu.cn　地址：同上

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出版历程
- 收稿日期: 2019-02-24
- 修回日期: 2019-08-06
- 网络出版日期: 2020-05-10
- 发布日期: 2020-06-30

Effects of converting years from farmland to forestland on soil physical properties in the loess area of western Shanxi Province, northern China

1.
School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
2.
Key Laboratory of National Forestry and Grassland Administration on Soil and Water Conservation, Beijing 100083, China
3.
Beijing Soil and Water Conservation Engineering Technology Research Center, Beijing 100083, China

摘要

摘要:
目的为评价晋西黄土区退耕年限对土壤物理性质的影响，并为该地区水土保持林构建提供依据。
方法以山西吉县蔡家川小流域的农地为对照，对晋西黄土区5种典型退耕还林林分（包括自然恢复山杨林、刺槐×侧柏人工混交林、油松×刺槐人工混交林、刺槐人工纯林和油松人工纯林）的土壤物理性质进行了连续23年的定位观测。
结果（1）所有人工林土壤密度随退耕年限呈现先上升（退耕后前1 ~ 4年）后下降（退耕后4 ~ 23年间）的趋势，在10 ~ 15年下降至一个比初始值更低的值后逐渐趋于平稳；自然恢复林随退耕年限土壤密度呈不断下降趋势，最高下降幅度为11.21%（0 ~ 20 cm土层）。（2）人工林土壤总孔隙度在前10 ~ 15年呈先下降后上升的趋势，自然恢复林土壤总孔隙度随恢复年限上升趋势越来越缓慢，0 ~ 20 cm土层和20 ~ 40 cm土层累积变化率为1.4%和0.6%。（3）5种典型林分的毛管孔隙度均随退耕年限增加呈上升趋势，其中人工林内20 ~ 40 cm土壤层的毛管孔隙度变化大于0 ~ 20 cm土层，自然恢复林0 ~ 20 cm土层和20 ~ 40 cm土层的累积变化率分别为2.5%和1.5%左右。
结论退耕年限对土壤物理性质影响显著（P < 0.05），4种人工林中土壤物理性质的变化主要发生在退耕后的前10 ~ 15年内，其中刺槐×侧柏混交林对土壤物理性质的改良效果更明显，建议该地区人工林恢复类型应以刺槐×侧柏混交林为主。
- 退耕还林 /
- 土壤物理性质 /
- 退耕年限 /
- 林分类型
Abstract:
ObjectiveThis paper aims to evaluate the effects of converting time from cropland to forestland on soil physical properties, and provide a basis for the construction of soil and water conservation forests in the region.
MethodThe 23 years positioning continuous monitoring was taken on soil physical properties under five typical forests, including one natural restoration Populus davidiana plantation, two mixed plantations of Platycladus orientalis and Robinia pseudoacacia, Pinus tabuliformis and Robinia pseudoacacia, two pure plantations of Robinia pseudoacacia and Pinus tabuliform, and taking the corn farmland as control.
Result(1) With the increase of converted years, the soil bulk density (BD) under the four plantations increased first and then decreased to a stable value, which was lower than initial value at about 10−15 years. In the natural restoration forest (NF), BD showed a downward tendency with the highest decreasing range of 11.21% at 0−20 cm soil depth. (2) The soil total porosity (TP) under the 4 plantations decreased first and then increased to a stable value, which was higher than initial value at about 10−15 years. The cumulative changing rates of TP at the soil depths of 0−20 cm and 20−40 cm were 1.4% and 0.6%, respectively under NF. (3) The capillary porosity (CP) under the five typical forests all showed an increasing trend with the increase of converting time. The CP at 0−20 cm changed more than at 20−40 cm in the plantations; the cumulative changing rates of CP at 0−20 cm and 20−40 cm were 2.5% and 1.5%, respectively under NF.
Conclution The converted years showed a significant effects on soil physical properties (P < 0.05) under the typical forests, while for the plantations, the change of BD and TP mostly occurred in the first 10−15 years. The mixed forests of Pinus tabuliformis and Robinia pseudoacacia should be the prioritized for the artificial vegetation restoration in the research area based on its remarkable improvement effects on soil physical properties.
- converting farmland to forestland /
- soil physical property /
- converting years from farmland to forestland /
- forest type

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图 1 恢复年限对土壤密度的影响

Figure 1. Effects of recovery time on soil bulk density

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图 2 恢复年限对土壤总孔隙度的影响

Figure 2. Effects of recovery time on soil total porosity

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图 3 恢复年限对土壤毛管孔隙度的影响

Figure 3. Effects of recovery time on soil capillary porosity

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图 4 不同植被类型下土壤有机质变化幅度

Figure 4. Changing range of soil organic matter under different vegetation types

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表 1 林地基本信息

Table 1 Basic information of the research sites

序号 No.	植被类型 Vegetation type	海拔 Altitude/m	坡度 Slope degree/（°）	坡向 Slope aspect/（°）	密度/（株·hm⁻²） Density/（plant·ha⁻¹）	胸径 DBH/cm	树高 Tree height/m	郁闭度 Canopy density
1	RP	1 195	18	NE32	1 386	12.8	8.5	0.84
2	PP	1 234	13	NE37	1 650	9.4	6.5	0.78
3	PRP	1 126	15	NE15	1 100 × 600	7.9 × 8.8	6.6	0.87
4	RPP	1 232	12	NE20	830 × 750	10.1 × 6.2	5.2	0.82
5	NP	1 158	19	NE45	1 530	8.7	7.3	0.92
6	CK	1 154	10	NE22	73 580	3.4	2.4	0.84
注：RP.刺槐人工林; PP.油松人工林; PRP.油松×刺槐混交林; RPP.刺槐×侧柏混交林; NP.自然恢复的山杨林; CK.耕地。NE.东北方向。下同。树高和胸径为平均值，耕地的郁闭度为玉米农作物的冠层覆盖度。Notes: RP, Robinia pseudoacacia plantation; PP, Pinus tabuliformis plantation; PRP, Pinus tabuliformis and Robinia pseudoacacia plantation; RPP, Robinia pseudoacacia and Platycladus orientalis plantation; NP, natural recovery Populus davidiana; CK, cultivated lands. NE, northeast aspect. The same below. Tree height and DBH are the average values, and the canopy density of cultivated land is the canopy coverage of corn crops.

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表 2 不同植被下0 ~ 20 cm与20 ~ 40 cm层土壤机械组成变化

Table 2 Changes of soil mechanical composition in 0−20 cm and 20−40 cm soil layers under different vegetations %

组成 Composition	土层深度 Soil depth/cm	项目 Item	RP	PP	PRP	RPP	NP	CK
黏粒 Clay	0 ~ 20	1993年 Year 1993	16.16	13.85	16.05	15.92	17.48	16.12
		2006年 Year 2006	15.75	14.25	16.15	16.04	19.73	15.97
		变化幅度 Range of change	− 2.54	2.89	0.62	0.75	12.87	− 0.93
	20 ~ 40	1993年 Year 1993	15.87	13.56	15.89	15.45	17.43	15.98
		2006年 Year 2006	15.72	13.79	15.94	15.62	18.13	16.04
		变化幅度 Range of change	− 0.95	1.70	0.31	1.10	4.02	0.38
粉粒 Silk	0 ~ 20	1993年 Year 1993	52.54	53.25	51.17	51.87	51.98	49.32
		2006年 Year 2006	53.02	53.51	51.80	52.27	52.02	49.49
		变化幅度 Range of change	0.91	0.49	1.23	0.77	0.08	0.34
	20 ~ 40	1993年 Year 1993	52.33	53.04	51.12	52.01	51.53	49.01
		2006年 Year 2006	52.51	53.08	51.47	52.32	52.35	49.00
		变化幅度 Range of change	0.34	0.08	0.68	0.60	1.59	− 0.02
砂粒 Sand	0 ~ 20	1993年 Year 1993	31.30	32.90	32.78	32.21	30.54	34.56
		2006年 Year 2006	31.23	32.24	32.05	31.69	28.25	34.54
		变化幅度 Range of change	− 0.22	− 2.01	− 2.23	− 1.61	− 7.50	− 0.06
	20 ~ 40	1993年 Year 1993	31.80	33.40	32.99	32.54	31.04	35.01
		2006年 Year 2006	31.77	33.13	32.59	32.06	29.52	34.96
		变化幅度 Range of change	−0.09	−0.81	− 1.21	− 1.48	− 4.90	− 0.14

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表 3 不同植被类型与恢复年限对土壤物理性质影响的方差分析

Table 3 Variance analysis on the effects of different vegetation types and recovery years on soil physical properties

土壤物理性质 Soil physical property	土层深度 Soil depth/cm	项目 Item	平方和 Sum of squares	自由度 df	均方 Mean squares	F	显著性 Sig.
土壤密度 Soil bulk density/ （g·cm⁻³）	0 ~ 20	恢复年限 Recovery time	0.158	22	0.007	12.589	0.000
		林分种类 Stand species	0.292	4	0.073	127.755	0.000
		总计 Total	44.103	114
	20 ~ 40	恢复年限 Recovery time	0.047	22	0.000	8.252	0.000
		林分种类 Stand species	0.155	4	0.039	148.384	0.000
		总计 Total	167.235	114
土壤总孔隙度 Soil total porosity/%	0 ~ 20	恢复年限 Recovery time	17.992	22	0.818	31.457	0.000
		林分种类 Stand species	2 186.973	4	546.743	21 029.616	0.000
		总计 Total	374 820.670	113
	20 ~ 40	恢复年限 Recovery time	7.711	22	0.350	11.236	0.000
		林分种类 Stand species	1 980.467	4	495.117	15 872.489	0.000
		总计 Total	243 388.632	113
土壤毛管孔隙度 Soil capillary porosity/%	0 ~ 20	恢复年限 Recovery time	2.834	22	0.129	2.624	0.001
		林分种类 Stand species	2 743.996	4	685.999	13 959.025	0.000
		总计 Total	173 816.589	84
	20 ~ 40	恢复年限 Recovery time	4.579	22	0.208	14.364	0.000
		林分种类 Stand species	2 864.019	4	716.005	49 417.602	0.000
		总计 Total	161 268.871	138

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