摘要: 目的为了解决塞罕坝地区华北落叶松人工林林下更新困难的问题，实现人工林近自然经营，开展人工促进措施（以下简称促更）对林下更新效果的研究十分必要、�/sec> 方法以塞罕坝地区31年生华北落叶松人工林为研究对象，采用裂区设计等试验方法，从林分密度、枯落物处理方式、种子来源以及种子处理方式这4个方面进行对比试验，探讨林下更新对不同促更措施的响应、�/sec> 结果处理后的华北落叶松林下均能更新，更新频率�?00%左右。同时期不同密度的幼苗地径、苗高在生长末期的差异较小（ P> 0.05），而幼苗地径在2年间存在显著性差异（ P< 0.05）。不同处理间生长季成活率无显著差异（ P> 0.05），整体维持�?3.68% ~ 87.87%范围内；而更新密度、播种发芽率在不同枯落物处理方式间差异显著（ P< 0.05）。人工播种时，以沟状清理（SC）的更新密度最大，�? 633.33 �?hm ²，该处理下种子发芽率最高，�?.79%。此外，更新动态因播种时间而发生改变。自然下种时，处理间的更新动态相对一致，7月底为幼苗萌发高峰期�?月中旬人工播种时，只有SC处理的种子在7月底适时大量萌发、�/sec> 结论清理枯落物层和播种对于促进华北落叶松林下更新是有效的。促更措施主要是通过影响幼苗数量而非幼苗品质来影响更新效果。播种时间和种子处理方式会对幼苗的更新动态产生影响，6月中旬人工播种无处理的种子会造成当年更新动态的延迟。本试验条件下最佳促更措施：一是在枯落物沟状清理后6月中旬前进行人工播种；二是全面清理枯落物，同时在前一年度�?1月初人工播种、�/sec>

关键诌�
• 华北落叶杽�/a> /
• 天然更新/
• 促进更新/
• 枯落�?/a> /
• 清理方式/
• 更新苖�/a>

Abstract: ObjectiveIn order to solve the problem of understory regeneration of Larix principis-rupprechtiiplantation in Saihanba Area of Hebei Province, northern China and realize the near-natural management of plantation, it is necessary to study the effects of artificial promotion measures (hereinafter referred to as “promotion�? on understory regeneration. MethodThis study took 31 years old L. principis-rupprechtiiplantation in Saihanba Area as the research object, we adopted the split plot design and other methods. The experiments of promotion were carried out from four aspects: stand density, litter treatment, seed source and seed treatment. This paper discusses the response of understory regeneration to different promotion measures. ResultThe results showed that the regeneration can appear among the treatments and the regeneration frequency was about 100%. The ground diameter and seedling height of seedlings with different densities at the same period had little difference at the end of growth ( P> 0.05), while the ground diameter of seedlings had significant differences in two years ( P< 0.05). There was no significant difference in survival rate between different treatments ( P>0.05), and the overall survival rate remained in the range of 43.68%�?7.87%. However, the regeneration density and germination rate of seeds were significantly different among litter treatments ( P< 0.05). The regeneration density of 8 633.33 plant/ha of sulcate cleaning (SC) was the highest under artificial sowing, and seed germination rate of 1.79% was also the highest. In addition, the dynamic of regeneration changed with sowing time. When the seeds were sown naturally, the regeneration dynamics among the treatments were relatively consistent, and the peak of seedling germination was at the end of July. When the seeds were sown artificially in the middle of June, only the seeds in SC treatment germinated in large quantities at the end of July. ConclusionThe artificial interference with litter layer and seeding are effective to promote the regeneration of L. principis-rupprechtiiplantations. The promotion measures mainly affect the effects of regeneration by affecting the number of seedlings rather than the seedling quality. The sowing time and seed treatments affect the renewal dynamics of seedlings, and artificial sowing of untreated seeds in mid-June can cause the delay of renewal dynamics in the current years. The best way to promote the regeneration of L. principis-rupprechtiiplantations is as follows: the first way is to sulcate clean the litter layer and spread the seeds manually before mid-June, the second way is comprehensively clean the litter layer and spread the seeds in early November of the previous year.

Key words:
• Larix principis-rupprechtii/
• natural regeneration/
• promoting regeneration/
• litter/
• clearance way/
• regenerated seedling

�?nbsp; 1裂区设计示意国�/p>

CK. 对照；CC. 全面清理；BC. 带状清理；SC. 沟状清理。图�?类枯落物处理方式在副区中是随机排列的，林分密度由小到大分别表示为T₁、T₂、T₃。下同。CK, control; CC, completely cleaning; BC, banding cleaning ; SC, sulcate cleaning. The order of 4 litter treatments is random in the subplot, and stand densities from small to large are expressed as T₁, T₂, T₃, respectively. The same below.

Figure 1.Schematic diagram of slip plot design

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 2带状清理（BC，a）和沟状清理（SC，b）示意图

灰色区域为副区中枯落物的堆积区，白色区域为副区中枯落物的清理区。The gray area is the accumulation area of litter and the white area is the cleaning area of litter in the figure.

Figure 2.Schematic diagram of banding cleaning (a) and sulcate cleaning (b)

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 3幼苗地径、苗高在不同时期的比辂�/p>

不同大写字母表示密度间的差异显著＇�i>P< 0.05），不同小写字母表示年份间的差异显著＇�i>P< 0.05）。Different capital letters indicate significant difference between varied densities (P< 0.05), and different small letters indicate significant difference between varied years (P< 0.05).

Figure 3.Comparison of seedling ground diameter and seedling height in different periods

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 42019�?020年不同林分密度下不同枯落物处理方式的更新密度

不同大写字母表示枯落物处理方式间的差异显著（P< 0.05），不同小写字母表示密度间的差异显著＇�i>P< 0.05）。图6同。Different capital letters indicate the difference between different litter treatment modes (P< 0.05), and different small letters indicate the difference between varied stand densities (P< 0.05). The same as figure 6.

Figure 4.Regenaration density of different litter treatment modes under varied stand densities in 2019 and 2020

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 5T₁、T₂、T₃林分密度�?019�?020年不同处理间生长季存活幼苗密度的动态变匕�/p>

Figure 5.Dynamic changes of survival seedling density in growing season among different treatments under T₁, T₂and T₃stand densities in 2019 and 2020

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 6人工播种下各项处理中种子发芽率比辂�/p>

Figure 6.Comparison of seed germination rate of different treatments under artificial sowing

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 72020年不同种子处理方式间生长季存活幼苗密度的动态变匕�/p>

Figure 7.Dynamic changes of survival seedling density in growing season among different seed treatments in 2020

下载: 全尺寸图牆�/a> 幻灯牆�/a>

�?nbsp; 1固定试验样地基本林分信息

Table 1.Basic stand information of fixed experimental sample plots

样地叶�br/>Sample plot No.	平均密度/（株ˑhm�?（�br/>Average density/(treeˑha�?)	平均胸径 Average DBH/cm	平均树高 Average tree height/m	平均冠幅 Average crown width/m	郁闭�?br/>Canopy density	海拔 Altitude/m	立地类型 Site type	土壤类型 Soil type	土层状况 Soil condition
T1	1 650 ± 78	14.76 ± 2.73	13.62 ± 1.58	2.45 ± 0.56	0.52	1 669	曼甸 Plateau	灰色森林圞�br/>Grey forest soil	厚土 Thick soil
T2	2 250 ± 125	13.29 ± 3.16	12.64 ± 1.96	2.21 ± 0.71	0.62
T3	2 850 ± 209	12.23 ± 3.57	12.71 ± 2.15	1.90 ± 0.83	0.67
TN	1 375 ± 65	14.92 ± 2.97	12.40 ± 1.76	2.59 ± 0.69	0.49

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�?nbsp; 2华北落叶松良种基本参�?/p>

Table 2.Basic parameters of high quality seeds ofL. principis-rupprechtii

平均粒径 Average grain diameter/mm	千粒质量 Thousand-grain mass/g	发芽玆�br/>Germination rate/%	生活劚�br/>Seed viability/%
1.56 ± 0.14	5.90 ± 0.19	88.89 ± 4.16	97.78 ± 1.57

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�?nbsp; 3裂区设计的样地处理详惄�/p>

Table 3.Treatment details of fixed experimental sample plots in slip plot design

林分密度 Stand density	枯落物处理方弎�br/>Litter treatment method	枯落物清理面�?br/>Litter clearing area/m2	播种种子密度 Seeding density			播种种子质量 Quality of seed propagation
			播散野�br/>Seeding amount/（g·m�?（�/td>	播种密度/（粒·m�?（�br/>Seeding density/（cap·m�?（�/td>		各副区质野�br/>Mass of each subplot/g	各副区粒�?br/>Grain number of each subplot
T1	CK	0	1.50	254.15		150.00	25 415.00
	CC	100				150.00	25 415.00
	BC	50				75.00	12 707.50
	SC	19				28.50	4 828.85
T2	CK	0	1.50	254.15		150.00	25 415.00
	CC	100				150.00	25 415.00
	BC	50				75.00	12 707.50
	SC	19				28.50	4 828.85
T3	CK	0	1.50	254.15		150.00	25 415.00
	CC	100				150.00	25 415.00
	BC	50				75.00	12 707.50
	SC	19				28.50	4 828.85

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�?nbsp; 44类种子处理方弎�/p>

Table 4.4 kinds of seed treatment methods

处理 Treatment	播种时间 Sowing time	越冬保存条件 Wintering preservation condition	雪藏方式 Snow storage mode	播种前是否催芼�br/>Whether to promote germination before sowing
ST1	2019�?1月上�?br/>Early November, 2019	塞罕坝室外环墂�br/>Outdoor environment of Saihanba Area	室外天然雪藏 Natural snow stratification in the outdoor environment	� No
ST2	2020�?月中�?br/>Mid-June, 2020	塞罕坝室内环墂�br/>Indoor environment of Saihanba Area	不雪藎�br/>No snow stratification	� No
ST3	2020�?月中�?br/>Mid-June, 2020	塞罕坝室内环墂�br/>Indoor environment of Saihanba Area	不雪藎�br/>No snow stratification	� Yes
ST4	2020�?月中�?br/>Mid-June, 2020	塞罕坝室内环墂�br/>Indoor environment of Saihanba Area	室内人工雪藏 Artificial snow storage in the indoor environment	� Yes

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�?nbsp; 52019年和2020年华北落叶松林各级幼苗的更新频率

Table 5.Regeneration frequency of seedlings at various levels inL. principis-rupprechtiiplantations in 2019 and 2020

林分 密度 Stand density	枯落�?br/>处理方式 Litter treatment mode	2019								2020
		1a	更新频率 Regeneration frequency/%	2a	更新频率 Regeneration frequency/%	3a+	更新频率 Regeneration frequency/%	整体更新频率 Overall regeneration frequency/%		1a	更新频率 Regeneration frequency/%	2a	更新频率 Regeneration frequency/%	3a+	更新频率 Regeneration frequency/%	整体更新频率 Overall regeneration frequency/%
T1	CK	∙�/td>	100		0		0	100		∙�/td>	100	∙�/td>	50		0	100
	CC	∙�/td>								∙�/td>
	BC	∙�/td>								∙�/td>		∙�/td>
	SC	∙�/td>								∙�/td>
T2	CK	∙�/td>	75	∙�/td>	25		0	75		∙�/td>	100	∙�/td>	25		0	100
	CC									∙�/td>
	BC	∙�/td>								∙�/td>
	SC	∙�/td>								∙�/td>
T3	CK	∙�/td>	100	∙�/td>	25		0	100		∙�/td>	100		25	∙�/td>	25	100
	CC	∙�/td>								∙�/td>
	BC	∙�/td>								∙�/td>		∙�/td>
	SC	∙�/td>								∙�/td>
注：1a. 1年生幼苗�?a. 2年生幼苗�?a+. 3年生及以上幼苗。存在更新的样地标注符号“√”，没有更新的样地不作任何标注。幼树更新频率均�?，故在表中省略。Notes: 1a means 1-year-old seedlings; 2a means 2-year-old seedlings; 3a+ means more than 3 years old seedlings. There is a symbol “√� for the regenerated sample plots; there is no mark for the non-regenerated sample plots, and the regeneration frequency of young trees in all sample plots is 0, it is omitted in the above table.

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�?nbsp; 62019年和2020年的华北落叶松更新等级评宙�/p>

Table 6.Evaluation of regeneration levels ofL. principis-rupprechtiiin 2019 and 2020

林分密度 Stand density	枯落物处理方弎�br/> Litter treatment mode	2019			2020
		更新密度/（株ˑhm�?（�br/> Regeneration density/（treeˑha�?（�/td>	更新等级 Regeneration grade		更新密度/（株ˑhm�?（�br/> Regeneration density/（treeˑha�?（�/td>	更新等级 Regeneration grade
T1	CK	266.67 ± 47.14a	不良 Bad		1 933.33 ± 758.65a	不良/中等 Bad or medium
	CC	66.67 ± 94.28b	不良 Bad		5 700.00 ± 1 489.97a	良好 Good
	BC	300.00 ± 216.02b	不良 Bad		7 466.67 ± 1 901.46a	良好 Good
	SC	100.00 ± 141.42a	不良 Bad		7 200.00 ± 3 706.75a	中等/良好 Medium or good
T2	CK	366.67 ± 449.69b	不良 Bad		1 833.33 ± 205.48a	不良/中等 Bad or medium
	CC	0.00 ± 0.00b	不良 Bad		4 300.00 ± 565.69a	中等/良好 Medium or good
	BC	100.00 ± 81.65b	不良 Bad		6 000.00 ± 648.07a	良好 Good
	SC	100.00 ± 141.42a	不良 Bad		11 100.00 ± 5 114.68a	良好 Good
T3	CK	566.67 ± 205.48b	不良 Bad		2 733.33 ± 449.69a	中等 Medium
	CC	33.33 ± 47.14b	不良 Bad		5 300.00 ± 1 737.81a	中等/良好 Medium or good
	BC	66.67 ± 94.28a	不良 Bad		6 433.33 ± 3 492.21a	中等/良好 Medium or good
	SC	100.00 ± 141.42b	不良 Bad		7 600.00 ± 2 698.15a	良好 Good

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�?nbsp; 72019年和2020年不同林分密度下幼苗生长季成活率比较

Table 7.Comparison of survival rate of seedlings in growing season under different standdensities in 2019 and 2020

林分密度 Stand density	生长季成活率 Survival rate in growing season/%
	2019	2020
T1	70.28 ± 18.57Aa	73.93 ± 8.54Aa
T2	77.22 ± 9.65Aa	62.11 ± 14.97Aa
T3	49.65 ± 37.12Aa	62.26 ± 7.67Aa
注：大写字母表示密度间的差异，小写字母表示年份间的差异。字母不同表示差异显著，差异显著性水�?.05。Notes: capital letters indicate the difference between varied densities, and small letters indicate the difference between varied years. Different letters mean significant difference, and the difference significance level is 0.05.

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�?nbsp; 82020年不同林分密度和不同处理方式下幼苗生长季成活率比辂�/p>

Table 8.Comparison of survival rate of seedlings in growing season of different litter treatment modes under varied stand densities in 2020

枯落物处理方弎�br/>Litter treatment mode	林分密度 Stand density
	T1	T2	T3
CK	68.25 ± 27.31Aa	57.30 ± 22.44Aa	72.25 ± 10.81Aa
CC	65.85 ± 9.16Aa	85.22 ± 16.92Aa	60.50 ± 2.00Aa
BC	87.87 ± 1.04Aa	62.22 ± 10.80Aa	65.17 ± 18.27Aa
SC	73.74 ± 5.18Aa	43.68 ± 8.25Aa	51.12 ± 16.89Aa
注：大写字母表示枯落物处理方式间的差异，小写字母表示密度间的差异。字母不同表示差异显著，差异显著性水�?.05。下同。Notes: capital letters indicate the difference between varied litter treatments, and small letters indicate the difference between varied stand densities. Different letters mean significant difference, the difference significance level is 0.05. The same below.

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[2]孙国�? 李文�? 黄选瑞, �? 华北落叶松人工林天然更新及与土壤因子的关系[J]. 安徽农业大学学报, 2017, 44(6): 1047�?051. doi:10.13610/j.cnki.1672-352x.20171214.026

Sun G L, Li W B, Huang X R, et al. Natural regeneration of the Larix principis-rupprechtiiplantation and its relation to the soil factors[J]. Journal of Anhui Agricultural University, 2017, 44(6): 1047�?051. doi:10.13610/j.cnki.1672-352x.20171214.026 [3]高润�? 郭晋�? 郭跃�? 山西文峪河上游河岸林的土壤种子库与树种更新特征[J]. 植物科学学报, 2011, 29(5): 580�?88.

Gao R M, Guo J P, Guo Y D. Characteristics of soil seed bank and tree regenerations of riparian forests in the upper reach of Wenyuhe Watershed in Shanxi Province[J]. Plant Science Journal, 2011, 29(5): 580�?88. [4]董伯�? 黄选瑞, 徐学�? �? 退化华北落叶松人工林林隙更新特征[J]. 中南林业科技大学学报, 2014, 34(8): 1�?.

Dong B Q, Huang X R, Xu X H, et al. Recruitment characteristics of gaps in degraded Larix pricipis-rupprechtiiplantation[J]. Journal of Central South University of Forestry & Technology, 2014, 34(8): 1�?. [5]罗梅, 郑小�? 金沟岭林场落叶松人工林天然更新动态研究[J]. 中南林业科技大学学报, 2016, 36(9): 7�?1.

Luo M, Zheng X X. Dynamic study of natural regeneration of Larix olgensisplantation in Jingouling Forest Farm[J]. Journal of Central South University of Forestry & Technology, 2016, 36(9): 7�?1. [6]王雯�? 欧景�? 刘晓, �? 秦岭华北落叶松林乔木种群结构与更新[J]. 生态科�? 2011, 30(6): 618�?23. doi:10.3969/j.issn.1008-8873.2011.06.010

Wang W W, Ou J L, Liu X, et al. A survey on regeneration of trees in Larix pricipis-rupprechtiiforest[J]. Ecological Science, 2011, 30(6): 618�?23. doi:10.3969/j.issn.1008-8873.2011.06.010 [7]程中�? 吴水�? 刘世�? 我国森林天然更新及人工促进天然更新的现状与展望[J]. 山西农业大学学报(自然科学�?, 2018, 38(10): 71�?6. doi:10.13842/j.cnki.issn1671-8151.201807003

Cheng Z Q, Wu S R, Liu S R. Current status and future perspectives of both natural and assisted natural forest regeneration in China[J]. Journal of Shanxi Agricultural University (Natural Science Edition), 2018, 38(10): 71�?6. doi:10.13842/j.cnki.issn1671-8151.201807003 [8]连相�? 鲁法�? 刘成�? �? 我国人工林天然更新研究进展[J]. 世界林业研究, 2013, 26(6): 52�?8. doi:10.13348/j.cnki.sjlyyj.2013.06.015

Lian X R, Lu F D, Liu C J, et al. Research progress of natural regeneration of forest plantation in China[J]. World Forestry Research, 2013, 26(6): 52�?8. doi:10.13348/j.cnki.sjlyyj.2013.06.015 [9]姜祛�? 辽西油松人工促进天然更新技术模式研究[D]. 沈阳: 沈阳农业大学, 2018.

Jiang Q H. Research on the technology of artificial promotion of the natural regeneration for Pinus tabuliformisin western Liaoning[D]. Shenyang: Shenyang Agricultural University, 2018. [10]刘铁�? 毕君, 王超, �? 冀北山地油松人工林天然更新研究[J]. 中南林业科技大学学报, 2017, 37(7): 55�?8, 65. doi:10.14067/j.cnki.1673-923x.2017.07.008

Liu T Y, Bi J, Wang C, et al. Study on the natural regeneration of Pinus tabuliformisplantation in the northern mountain of Hebei Province[J]. Journal of Central South University of Forestry & Technology, 2017, 37(7): 55�?8, 65. doi:10.14067/j.cnki.1673-923x.2017.07.008 [11]赵�? 贾宏�? 蔡道�? �? 红椎天然更新及其影响因子研究[J]. 北京林业大学学报, 2018, 40(11): 76�?3. doi:10.13332/j.1000-1522.20180190

Zhao Z, Jia H Y, Cai D X, et al. Natural regeneration and its influencing factors of Castanopsis hystrix[J]. Journal of Beijing Forestry University, 2018, 40(11): 76�?3. doi:10.13332/j.1000-1522.20180190 [12]李玉�? 袁春�? 刘淑�? �? 章古台固沙林更新造林中天然更新的结合与利用[J]. 防护林科技, 2008(5): 35�?7. doi:10.13601/j.issn.1005-5215.2008.05.028

Li Y H, Yuan C L, Liu S L, et al. Combination & utilization of natural regeneration of regeneration planting on fixing sand forest in Zhanggutai Region[J]. Protection Forest Science and Technology, 2008(5): 35�?7. doi:10.13601/j.issn.1005-5215.2008.05.028 [13]唐继�? 贾宏�? 曾冀, �? 南亚热带米老排人工林皆伐迹地天然更新研究[J]. 中南林业科技大学学报, 2018, 38(3): 59�?3. doi:10.14067/j.cnki.1673-923x.2018.03.010

Tang J X, Jia H Y, Zeng J, et al. Natural regeneration on clearcut land of Mytilaria laosensisplantation in south subtropical area of China[J]. Journal of Central South University of Forestry & Technology, 2018, 38(3): 59�?3. doi:10.14067/j.cnki.1673-923x.2018.03.010 [14]陈永�? 森林天然更新障碍机制研究进展[J]. 世界林业研究, 2012, 25(2): 41�?5. doi:10.13348/j.cnki.sjlyyj.2012.02.013

Chen Y F. Research progress of natural regeneration barrier of forest[J]. World Forestry Research, 2012, 25(2): 41�?5. doi:10.13348/j.cnki.sjlyyj.2012.02.013 [15]李小�? 彭明�? 党承�? 植物自然更新研究进展[J]. 生态学杂志, 2007, 26(12): 2081�?088. doi:10.13292/j.1000-4890.2007.0364

Li X S, Peng M C, Dang C L. Research progress on natural regeneration of plants[J]. Chinese Journal of Ecology, 2007, 26(12): 2081�?088. doi:10.13292/j.1000-4890.2007.0364 [16]朱教�? 刘足�? 王贺�? 辽东山区长白落叶松人工林天然更新障碍分析[J]. 应用生态学�? 2008, 19(4): 695�?03. doi:10.13287/j.1001-9332.2008.0213

Zhu J J, Liu Z G, Wang H X. Obstacles for natural regeneration of Larix olgensisplantations in montane regions of eastern Liaoning Province, China[J]. Chinese Journal of Applied Ecology, 2008, 19(4): 695�?03. doi:10.13287/j.1001-9332.2008.0213 [17]张树�? 李梅, 张树�? �? 塞罕坝华北落叶松人工林天然更新影响因子[J]. 生态学�? 2015, 35(16): 5403�?411.

Zhang S Z, Li M, Zhang S B, et al. Factors affecting natural regeneration of Larix principis-rupprechtiiplantations in Saihanba of Hebei, China[J]. Acta Ecologica Sinica, 2015, 35(16): 5403�?411. [18]张小�? 王得�? 杜江�? �? 微生境对华山松人工林天然更新的影响[J]. 西北农林科技大学学报(自然科学�?, 2018, 46(1): 39�?5.

Zhang X P, Wang D X, Du J T, et al. Effects of microhabitat on natural regeneration of artificial Pinus armandiiplantation[J]. Journal of Northwest A&F University (Natural Science Edition), 2018, 46(1): 39�?5. [19]喻方�? 周景�? 林木种苗质量检验技术[M]. 北京: 中国林业出版�? 2008: 20�?8.

Yu F Y, Zhou J L. Quality inspection techniques of forest tree seedlings[M]. Beijing: China Forestry Publishing House, 2008: 20�?8. [20]刘足�? 朱教�? 袁小�? �? 辽东山区长白落叶松天然更新调查[J]. 林业科学, 2007, 43(1): 42�?9. doi:10.3321/j.issn:1001-7488.2007.01.007

Liu Z G, Zhu J J, Yuan X L, et al. Investigation and analysis of the natural regeneration of Larix olgensisin mountain regions of eastern Liaoning Province, China[J]. Scientia Silvae Sinicae, 2007, 43(1): 42�?9. doi:10.3321/j.issn:1001-7488.2007.01.007 [21]杨秀�? 影响关帝山华北落叶松天然更新与幼苗存活的微生境变量分析[J]. 山西农业大学学报(自然科学�?, 2010, 30(6): 542�?47. doi:10.13842/j.cnki.issn1671-8151.2010.06.017

Yang X Q. Analysis on micro-habitat variables affecting natural regeneration and survial of Larix principis-rupprechtiiseedlings in Guandi Mountain[J]. Journal of Shanxi Agricultural University (Natural Science Edition), 2010, 30(6): 542�?47. doi:10.13842/j.cnki.issn1671-8151.2010.06.017 [22]Zerbe S. Restoration of natural broad-leaved woodland in Central Europe on sites with coniferous forest plantations[J]. Forest Ecology and Management, 2002, 167(1�?): 27�?2. doi:10.1016/S0378-1127(01)00686-7 [23]崔丽�? 孙海�? 张曼, �? 华北落叶松和油松混交林林隙特征及更新研究[J]. 西北林学院学�? 2015, 30(1): 14�?9. doi:10.3969/j.issn.1001-7461.2015.01.03

Cui L H, Sun H J, Zhang M, et al. Forest gap characteristics and regeneration of Larix principis-rupprechtiiand Pinus tabulaeformismixed forest[J]. Journal of Northwest Forestry University, 2015, 30(1): 14�?9. doi:10.3969/j.issn.1001-7461.2015.01.03 [24]张树�? 塞罕坝华北落叶松人工林种群更新特征及影响因素[D]. 保定: 河北农业大学, 2014.

Zhang S Z. Analysis on regeneration characteristics and factors affecting natural regeneration of Larix principis-rupprechtiiplantations in Saihanba Forest Farm [D]. Baoding: Heibei Agricultural University, 2014. [25]郭晋�? 李海�? 刘宁, �? 华北落叶松和白杄幼苗对光照和竞争响应的差异比较[J]. 林业科学, 2009, 45(2): 53�?9. doi:10.3321/j.issn:1001-7488.2009.02.010

Guo J P, Li H B, Liu N, et al. Comparison of responses of Larix principis-rupprechtiiand Picea meyeriseedling growth to light availability and planting density under controlled environment[J]. Scientia Silvae Sinicae, 2009, 45(2): 53�?9. doi:10.3321/j.issn:1001-7488.2009.02.010 [26]Aussenac G. Interactions between forest stands and microclimate: ecophysiological aspects and consequences for silviculture[J]. Annals of Forest Science, 2000, 57(3): 287�?01. doi:10.1051/forest:2000119 [27]李进, 石晓�? 高润�? �? 华北落叶松天然次生林更新及影响因素[J]. 森林与环境学�? 2020, 40(6): 588�?96.

Li J, Shi X D, Gao R M, et al. Regeneration and affecting factors of Larix principis-rupprechtiinatural secondary forests[J]. Journal of Forest and Environment, 2020, 40(6): 588�?96. [28]刘忠�? 刘建�? 胡伟, �? 不同密度胡桃楸次生林枯落物和土壤持水特性的研究[J]. 森林工程, 2021, 37(3): 52�?9,66. doi:10.3969/j.issn.1006-8023.2021.03.007

Liu Z L, Liu J M, Hu W, et al. Water-holding characteristics of litter and soil of Juglans mandshuricanatural secondary forest with different densities[J]. Forestry Engineering, 2021, 37(3): 52�?9,66. doi:10.3969/j.issn.1006-8023.2021.03.007 [29]梁文�? 华北土石山区典型林分健康经营技术基础研究[D]. 北京: 北京林业大学, 2013.

Liang W J. Basic research on typical forest health management technology in rocky mountain area of northern China[D]. Beijing: Beijing Forestry University, 2013. [30]Vitale M, Savi F, Baldantoni D, et al. Modeling of early stage litter decomposition in Mediterranean mixed forests: functional aspects affected by local climate[J]. iForest-Biogeosciences and Forestry, 2014, 8(4): 517�?25. [31]罗梅, 郑小�? 北京十三陵林场人工侧柏林天然更新研究[J]. 西北农林科技大学学报(自然科学�?, 2012, 40(12): 73�?8. doi:10.13207/j.cnki.jnwafu.2012.12.031

Luo M, Zheng X X. Natural regeneration of artifical Platycladus orientalisstands in Shisanling Forest Farm, Beijing[J]. Journal of Northwest A&F University (Natural Science Edition), 2012, 40(12): 73�?8. doi:10.13207/j.cnki.jnwafu.2012.12.031 [32]Cintra R. Leaf litter effects on seed and seedling predation of the palm Astrocaryum murumuruand the legume tree Dipteryx micranthain Amazonian forest[J]. Journal of Tropical Ecology, 1997, 13(5): 709�?25. doi:10.1017/S0266467400010889 [33]罗桂�? 马履一, 贾忠�? �? 油松人工林林隙天然更新及与环境相关性分析[J]. 北京林业大学学报, 2019, 41(9): 59�?8. doi:10.13332/j.1000-1522.20180416

Luo G S, Ma L Y, Jia Z K, et al. Correlation analysis between natural regeneration and environment in canopy gap of Chinese pine ( Pinus tabuliformis) plantation[J]. Journal of Beijing Forestry University, 2019, 41(9): 59�?8. doi:10.13332/j.1000-1522.20180416 [34]董伯�? 华北落叶松林更新过程与枯落物蓄水功能对经营措施的响应[D]. 保定: 河北农业大学, 2011.

Dong B Q. The response of regeneration process and litter water storage function of Larix principis-rupprechtiion management measures[D]. Baoding: Heibei Agricultural University, 2011.