青海黄土高寒区4种典型人工林树木叶片碳氮磷含量及化学计量特征

doi:10.11707/j.1001-7488.20220103

摘要/Abstract

摘要：

目的: 探究青海黄土高寒区4种典型人工林树木(针叶和阔叶2种生活型)叶片的有机碳(OC)、全氮(TN)、全磷(TP)含量和化学计量特征，及其随生长季阶段(Ⅰ：5月15日—6月15日; Ⅱ：6月15日—7月15日; Ⅲ：7月15日—8月15日)和坡位的变化，为指导青海高寒森林的经营管理提供科学依据。方法: 野外采集华北落叶松、青海云杉、白桦和青杨4种树木叶片样品，室内测定叶片的OC、TN和TP含量，通过正态性检验、单因素方差分析、邓肯多重比较、相关性分析、除趋势对应分析、冗余分析和蒙特卡洛置换检验，探究叶片养分含量及化学计量特征。结果: 4种树木叶片的OC、TN和TP含量平均值(变化范围)分别为591.84(571.19~605.67)、17.76(7.14~27.62)和1.47(0.81~2.65)g ·kg^-1，变异系数表现为TP > TN > OC; 阔叶树叶片TN含量高于针叶树，阔叶树叶片TN和TP含量受生长季阶段的影响大于针叶树; 4种树木叶片的C ∶N(OC ∶TN)、C ∶P(OC ∶TP)和N ∶P(TN ∶TP)平均值(变化范围)为38.87 (26.04~97.73)、1 042.97(667.53~1 971.00)和28.32(18.87~51.50)，变异系数表现为C ∶N < N ∶P < C ∶P; 阔叶树叶片C ∶N和C ∶P受生长季阶段的影响大于针叶树; 除青海云杉外，其他3种树木叶片的TN和TP含量极显著正相关(P < 0.01); 生长季阶段和生活型均极显著影响树木叶片OC、TN和TP含量及化学计量比(P < 0.01)，而坡位影响不显著(P>0.05)。结论: 青海黄土高寒区青海云杉叶片C ∶N和C ∶P较高，N ∶P较低，说明其生长较慢且更多受TN限制，要注意TN养分的补给。生长季阶段和针叶、阔叶生活型是影响青海黄土高寒区4种树木叶片养分含量和化学计量比的显著因素(P < 0.01)，养分管理要关注树木所属的生活型和所处的生长季阶段。

关键词: 叶片养分, 生态化学计量比, 生活型, 生长季阶段, 坡位

Abstract:

Objective: The purpose of this study was to investigate the contents of organic carbon (OC), total nitrogen (TN), and total phosphorus (TP) and their stoichiometric characteristics in leaves of four typical plantation species (coniferous and broad-leaved life forms) in the alpine zone of the Loess Plateau in Qinghai, and their changes with the stages of the growing season (Ⅰ: May 15 to June 15; Ⅱ: June 15 to July 15; Ⅲ: July 15 to August 15) and the slope positions, and to provide a scientific basis for the management of forest in Qinghai. Method: The OC, TN, and TP in leaf samples of four typical plantation species (Larix principis-rupprechtii, Picea crassifolia, Betula platyphylla, and Populus cathayana) were measured by field manual sampling and indoor experimental analysis. The nutrient contents and stoichiometric characteristics were analyzed by normality test, one-way analysis of variance, Duncan multiple comparison, correlation analysis, detrended correspondence analysis, redundancy analysis, and Monte Carlo permutation test. Result: The mean values and variation range of the OC, TN, and TP contents in leaves of the four typical plantation species in the alpine zone of the Loess Plateau in Qinghai were 591.84 (571.19-605.67), 17.76 (7.14-27.62), and 1.47 (0.81-2.65) g·kg^-1, respectively. The coefficients of variation were ranked TP> TN> OC. The leaf TN content of the broad-leaved trees was higher than that of the coniferous trees. The leaf TN content and TP content of the broad-leaved trees were more affected by the stages of the growing season than that of the coniferous trees. The mean values and variation range of leaf C ∶N (OC ∶TN), C ∶P (OC ∶TP), and N ∶P (TN ∶TP) were 38.87 (26.04-97.73), 1 042.97 (667.53-1 971.00), and 28.32 (18.87-51.50), respectively. The coefficients of variation were ranked C ∶N < N ∶P < C ∶P. The leaf C ∶N and C ∶P of the broad-leaved trees were more affected by the stages of the growing season than that of the coniferous trees. Except for P. crassifolia, the contents of TN and TP in leaves of the other three tree species showed a very significant positive correlation (P < 0.01). The effects of stages of the growing season and life forms on leaf OC, TN, and TP contents and stoichiometric ratios of the four typical plantation species reached extreme levels of significance (P < 0.01), while the effect of slope positions was not significant (P>0.05). Conclusion: In the alpine zone of the Loess Plateau in Qinghai, the mean values of C ∶N and C ∶P in leaves of P. crassifolia were at a high level, while N ∶P was at a low level, indicating that the growth rate of P. crassifolia was relatively slow and the major reason was probably the limitation of TN. Attention should be paid to the supply of TN nutrient. Since the stages of growing season and the life form were two significant factors affecting leaf nutrient contents and stoichiometric ratios of the four typical plantation species (P < 0.01), both of them should be concerned carefully in the nutrient management in the alpine zone of the Loess Plateau in Qinghai.

Key words: leaf nutrient, ecological stoichiometry ratio, life form, stage of the growing season, slope position

中图分类号:

S718.55

温文杰,王冬梅. 青海黄土高寒区4种典型人工林树木叶片碳氮磷含量及化学计量特征[J]. 林业科学, 2022, 58(1): 22-31.

Wenjie Wen,Dongmei Wang. Content and Stoichiometric Characteristics of Carbon, Nitrogen, and Phosphorus in Leaves of Four Typical Plantation Species in the Alpine Zone of the Loess Plateau in Qinghai[J]. Scientia Silvae Sinicae, 2022, 58(1): 22-31.

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林分类型 Forest types	样地编号 Plot codes	海拔 Altitude/m	坡度 Slope/(°)	坡向 Slope aspect	坡位 Slope position	平均树高 Mean tree height/m	平均胸径 Mean DBH/cm
华北落叶松林 L. principis- rupprechtii forest	1	2 786	15.4	阴坡Shady slope	下坡Downhill	7.5	10.4
	2	2 817	12.4	阴坡Shady slope	下坡Downhill	9.0	16.3
	3	2 820	7.8	阴坡Shady slope	下坡Downhill	9.8	18.4
	4	2 840	12.9	阴坡Shady slope	中坡Mid-slope	8.7	14.7
	5	2 910	13.0	阴坡Shady slope	中坡Mid-slope	11.6	12.7
	6	2 920	25.0	阴坡Shady slope	上坡Uphill	8.9	14.2
	7	2 930	14.3	阴坡Shady slope	上坡Uphill	11.9	13.0

青海云杉林 P. crassifolia forest	8	2 822	19.5	阴坡Shady slope	下坡Downhill	7.9	12.1
	9	2 826	18.8	阴坡Shady slope	下坡Downhill	8.7	12.2
	10	2 871	17.7	阴坡Shady slope	中坡Mid-slope	8.5	11.5
	11	2 878	14.1	阴坡Shady slope	中坡Mid-slope	8.6	14.1
	12	2 907	20.9	阴坡Shady slope	上坡Uphill	9.6	12.9
	13	2 911	18.9	阴坡Shady slope	上坡Uphill	11.8	12.2

白桦林 B. platyphylla forest	14	2 802	16.3	阴坡Shady slope	下坡Downhill	6.2	14.3
	15	2 812	16.3	阴坡Shady slope	下坡Downhill	5.5	8.3
	16	2 862	16.4	阴坡Shady slope	中坡Mid-slope	3.3	9.5
	17	2 851	19.3	阴坡Shady slope	中坡Mid-slope	3.5	9.9
	18	2 921	19.5	阴坡Shady slope	上坡Uphill	6.3	14.1
	19	2 889	16.5	阴坡Shady slope	上坡Uphill	3.9	12.3

青杨林 P. cathayana forest	20	2 803	17.2	阴坡Shady slope	下坡Downhill	8.8	16.9
	21	2 804	25.0	阴坡Shady slope	下坡Downhill	8.7	2.9
	22	2 826	6.4	阴坡Shady slope	中坡Mid-slope	7.0	11.3
	23	2 835	6.7	阴坡Shady slope	中坡Mid-slope	7.4	12.1
	24	2 847	17.1	阴坡Shady slope	上坡Uphill	7.8	13.5
	25	2 860	18.5	阴坡Shady slope	上坡Uphill	7.3	10.6

元素 Elements	项目 Item	华北落叶松 L. principis-rupprechtii	青海云杉 P. crassifolia	白桦 B. platyphylla	青杨 P. cathayana
OC	n	15	12	11	12
	AM/(g·kg^-1)	599.81	591.47	605.77	571.19
	GM/(g·kg^-1)	599.69	590.69	605.67	571.08
	CV(%)	2.08	5.16	1.90	2.02
	P_(S-W)	0.113	0.001	0.021	0.736

TN	n	15	12	11	12
	AM/(g·kg^-1)	22.67	7.14	27.62	23.31
	GM/(g·kg^-1)	22.26	7.10	27.36	22.58
	CV(%)	19.41	11.90	14.67	26.08
	P_(S-W)	0.634	0.593	0.401	0.264

TP	n	15	9	11	12
	AM/(g·kg^-1)	2.65	0.85	1.57	2.25
	GM/(g·kg^-1)	2.32	0.81	1.18	1.57
	CV(%)	44.91	37.65	66.24	68.00
	P_(S-W)	0.061	0.005	0.047	0.217

元素 Elements	项目 Item	针叶树 Coniferous trees	阔叶树 Broad-leaved trees	P₂
OC	Ⅰ/(g·kg^-1)	600.48±10.86a	590.12±20.97a	0.134
	Ⅱ/(g·kg^-1)	585.68±36.34a	586.39±27.54a	0.969
	Ⅲ/(g·kg^-1)	600.54±14.15a	584.68±16.35a	0.103
	P₁	0.299	0.873

TN	Ⅰ/(g·kg^-1)	17.51±10.13a	29.65±3.36a	0.001
	Ⅱ/(g·kg^-1)	13.89±6.35a	22.17±3.94b	0.016
	Ⅲ/(g·kg^-1)	14.51±7.70a	20.70±4.30b	0.116
	P₁	0.606	0.000

TP	Ⅰ/(g·kg^-1)	2.36±1.57a	3.07±0.83a	0.195
	Ⅱ/(g·kg^-1)	1.77±0.64a	1.35±0.66b	0.265
	Ⅲ/(g·kg^-1)	0.85±0.13a	0.41±0.15c	0.003
	P₁	0.167	0.000

元素 Elements	项目 Item	针叶树 Coniferous trees	阔叶树 Broad-leaved trees	P₂
OC	下坡Downhill/(g·kg^-1)	603.95±11.74a	592.28±16.17a	0.104
	中坡Mid-slope/(g·kg^-1)	586.84±33.67a	583.83±23.58a	0.836
	上坡Uphill/(g·kg^-1)	596.73±13.07a	587.64±23.69a	0.358
	P₃	0.838	0.755

TN	下坡Downhill/(g·kg^-1)	16.28±9.11a	24.41±6.08a	0.058
	中坡Mid-slope/(g·kg^-1)	14.59±7.69a	26.27±6.70a	0.005
	上坡Uphill/(g·kg^-1)	16.45±9.61a	25.30±4.27a	0.032
	P₃	0.886	0.824

TP	下坡Downhill/(g·kg^-1)	2.10±1.46a	1.38±1.09a	0.299
	中坡Mid-slope/(g·kg^-1)	2.10±1.10a	2.21±1.59a	0.870
	上坡Uphill/(g·kg^-1)	1.86±1.37a	2.12±1.28a	0.705
	P₃	0.921	0.449

计量比 Stoichiometric ratios	项目 Item	华北落叶松 L. principis-rupprechtii	青海云杉 P. crassifolia	白桦 B. platyphylla	青杨 P. cathayana
C∶N	n	15	12	11	12
	AM	32.04	97.73	26.04	30.45
	GM	31.43	97.14	25.83	29.50
	CV(%)	19.79	11.48	12.90	26.01
	P_(S-W)	0.188	0.515	0.424	0.391

C∶P	n	15	9	11	12
	AM	803.11	1 971.00	1 876.90	1 640.37
	GM	667.53	1 877.43	1 330.24	938.01
	CV(%)	71.89	30.39	87.87	120.79
	P_(S-W)	0.000	0.274	0.013	0.000

N∶P	n	15	9	11	12
	AM	24.80	19.63	69.01	45.55
	GM	21.24	18.87	51.50	31.80
	CV(%)	70.28	24.71	83.61	99.71
	P_(S-W)	0.000	0.040	0.006	0.000