北京绿化树种油松、雪松和刺槐树干液流的空间变异特征

doi:10.3773/j.issn.1005-264x.2010.08.005

摘要/Abstract

摘要：

城市绿化树木具有多重生态效应, 其耗水量不容忽视。在不了解树干液流空间变异的前提下, 将点的测定值推广到整树或者林段尺度会产生很大的误差。为准确地确定整树耗水, 采用热消散探针法研究了夏秋季北京成年常绿树种油松(Pinus tabulaeformis)、雪松(Cedrus deodara)和刺槐(Robinia pseudoacacia)树干液流的空间变异特征及产生原因。各树种树干液流存在方位变异, 受树干靠南的方向受光较多、木材解剖特征和枝下高高度的影响, 油松和雪松液流密度与方位之间的关系较为固定, 而刺槐液流密度与方位之间的关系表现出随机性。不同方位每小时液流密度之间高度相关(p < 0.000 1)。因此, 可以基于这种关系准确地计算其他方位的液流(R² > 0.91, p < 0.000 1)。油松和雪松树干液流的径向变异显著, 较深处和较浅处树干液流的日变化格局相似, 但是较深处的液流明显滞后于较浅处的树干液流, 且较浅处树干液流对环境因子的响应远高于深处的液流。不同深度树干液流之间密切相关, 因此可以利用较浅处的液流外推其他深度的液流(R² > 0.89, p < 0.000 1)。然而, 同一棵树不同方位径向剖面特征不同, 雪松南向较深处的液流明显高于其他方位, 且滞后不显著, 这与树冠南向受光较多有关。结合误差分析, 采取北向15 mm和75 mm深处的液流密度均值来估算整树耗水较为准确。

关键词: 雪松, 油松, 方位和径向变异, 刺槐, 热消散探针法

Abstract:

Aims Water consumption of urban plants with multiple ecological effects is important. However, large errors may occur when sap flow is scaled from single point measurement to whole tree without knowledge of spatial sap flow profiles in the trunk. Our objective was to investigate the spatial variation of sap flux density (J_s) and its possible cause to estimate whole-tree water use more precisely.

Methods Spatial patterns of sap flux density in the sapwood of Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia were investigated with thermal dissipation probe from June to November 2008 in Beijing, China.

Important findings Axial variation was substantial. Due to greater exposure to sun in the south aspect, the anatomy of the xylem structure and lower branch height, there was an apparent relationship between sap flux density and aspect in P. tabulaeformis and C. deodara, but no apparent relationship in R. pseudoacacia. Hourly J_s over 24 h at different aspects were highly correlated; therefore, mean J_s may be accurately estimated based on measurement obtained on one aspect. J_s showed marked radial variation within the trunk. J_s at different depths show similar diurnal pattern, while J_s at deeper depth lagged behind and was more sensitive to evaporative demand than the shallower depth. Hourly J_s over 24 h at different depths were highly correlated, so J_s at a particular depth could be extrapolated as a multiple of J_s at the depth of 15 mm. However, depth profiles of J_s differed among aspects within a tree. J_s at the deeper depth on the south aspect of C. deodara was greater and had no time lag compared to other aspects. In conclusion, sap flux density on the north side at depths of 15 and 70 mm could give an accurate estimation of whole-tree transpiration.

Key words: Cedrus deodara, Pinus tabulaeformis, radial and axial variation, Robinia pseudoacacia, thermal dissipation probe method

王华, 欧阳志云, 郑华, 王效科, 倪永明, 任玉芬. 北京绿化树种油松、雪松和刺槐树干液流的空间变异特征. 植物生态学报, 2010, 34(8): 924-937. DOI: 10.3773/j.issn.1005-264x.2010.08.005

WANG Hua, OUYANG Zhi-Yun, ZHENG Hua, WANG Xiao-Ke, NI Yong-Ming, REN Yu-Fen. Characteristics of spatial variations in xylem sap flow in urban greening tree species Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia in Beijing, China. Chinese Journal of Plant Ecology, 2010, 34(8): 924-937. DOI: 10.3773/j.issn.1005-264x.2010.08.005

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链接本文: https://www.plant-ecology.com/CN/10.3773/j.issn.1005-264x.2010.08.005

https://www.plant-ecology.com/CN/Y2010/V34/I8/924

图/表 14

表1 树干液流测定样木的树形特征

Table 1 Characteristics of tree structures in the sampled trees for sap flow measurements

树种 Species	胸径 DBH (cm)	高度 Height (m)	冠层投影面 A_c (m²)	边材面积 A_s (cm²)	插针方位 Orientation of sensor	插针数量和类型 Number and type of sensor
油松1号 Pinus tabulaeformis No. 1	17.00	5.90	22.02	163.56	南北 Northsouth	2TDP30
油松2号 P. tabulaeformis No. 2	16.20	5.70	19.97	147.52	南北 Northsouth	2TDP30
油松3号 P. tabulaeformis No. 3	18.70	5.80	23.31	200.60	南北 Northsouth	2TDP30 + 1TDP80
雪松1号 Cedrus deodara No. 1	23.50	7.30	37.59	300.63	东南西北 All aspects	4TDP30
雪松2号 C. deodara No. 2	24.20	6.40	23.22	313.50	东南西北 All aspects	4TDP30
雪松3号 C. deodara No. 3	33.60	11.20	59.53	500.86	东南西北 All aspects	4TDP80
刺槐1号 Robinia pseudoacacia No. 1	40.40	11.50	56.71	138.80	东南西北 All aspects	4TDP30
刺槐2号 R. pseudoacacia No. 2	38.60	12.30	71.00	129.57	东南西北 All aspects	4TDP30
刺槐3号 R. pseudoacacia No. 3	33.50	12.10	42.96	104.59	东南西北 All aspects	4TDP30

图1 测定液流期间环境因子的变化。

Fig. 1 Variations of environmental factors during the sap flow measurement.

图2 油松不同方位树干液流特征。 A-C, 2008年6月油松每一株测定样树南北向树干液流密度的日变化。E-F, 北向液流密度(x轴)与南向液流密度(y轴)之间的线性关系。

Fig. 2 Characteristics of sap flux density (Js) at south and north aspects in Pinus tabulaeformis. A-C, Diurnal variation in Js at south and north aspects in each of three Pinus tabulaeformis trees on June, 2008. E-F, Linear relationships between Js on north side (x-axis) and Js on south side (y-axis).

图3 雪松东南西北4个方位的树干液流特征。 A-C, 2008年6月雪松每一株测定样树东南西北向树干液流密度的日变化。E-F, 北向液流密度(x轴)与东向、南向、西向液流密度(y轴)之间的线性关系。

Fig. 3 Characteristics of sap flux density (Js) at north, south, east and west aspects in Cedrus deodara trees. A-C, Diurnal variation in Js at four aspects in each of three Cedrus deodara trees in June, 2008. E-F, Linear relationships between Js on north side (x-axis) and Js on east, south and west sides (y-axis).

图4 刺槐东南西北4个方位的树干液流特征。 A-C, 2008年6月刺槐每一株测定样树东南西北向树干液流密度的日变化。E-F, 北向液流密度(x轴)与东、南、西向液流密度(y轴)之间的线性关系。

Fig. 4 Characteristics of sap flux density (Js) at north, south, east and west aspects in Robinia pseudoacacia trees. A-C, Diurnal variation in Js at four aspects in each of three Robinia pseudoacacia trees in June, 2008. E-F, Linear relationships between Js on north side (x-axis) and Js on east, south and west sides (y-axis).

表2 2008年6月到11月油松、雪松和刺槐东、南、西方位液流密度与北向液流密度(x轴)之间的曲线拟合结果

Table 2 Curve estimation between sap flux density (Js) on north side (x-axis) and Js on east, south, west side (y-axis) in each of three Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia trees from June to November, 2008

物种 Species	方位 Orientation	方程 Equation	解释量 R²	显著度 p
油松 P. tabulaeformis	南和北 South and North	J_s-south = 5e - 5 + 1.075J_s-north	0.971	< 0.000 1
雪松 C. deodara	东和北 East and North	J_s-east = 3e - 5 + 0.807J_s-north	0.957	< 0.000 1
	南和北 South and North	J_s-south = 0.0001 + 1.038J_s-north	0.905	< 0.000 1
	西和北 West and North	J_s-west = 1e - 5 + 0.817J_s-north	0.936	< 0.000 1
刺槐 R. pseudoacacia	东和北 East and North	J_s-east = - 6e - 6 + 0.988J_s-north	0.955	< 0.000 1
	南和北 South and North	J_s-south = 2.9e - 5 + 0.930J_s-north	0.967	< 0.000 1
	西和北 West and North	J_s-west = - 1e - 5 + 1.072J_s-north	0.984	< 0.000 1

表3 油松、雪松和刺槐东西和南北冠幅差异的独立t检验

Table 3 The t-test for canopy width from south to north and canopy width from east to west of three Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia trees

树种 Species	方差同质性检验 Levene’s test for equality of variances			均值的t检验 t-test for equality of means
	F	显著度 p	t	自由度 df	显著度 p
油松 P. tabulaeformis,	1.176	0.339	1.796	4	0.147
雪松 C. deodara	0.175	0.697	0.904	4	0.417
刺槐 R. pseudoacacia	7.748	0.050	2.500	4	0.067

表4 2008年6月到11月油松、雪松、刺槐不同方位树干液流与水汽压亏缺、总辐射之间的曲线拟合结果

Table 4 Curve estimation between sap flux density (Js) at four aspects and vapor pressure deficit (D), total radiation (Rs) in Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia from June to November, 2008

物种 Species	方位 Orientation	环境因子 Environmental factors	方程 Equation	解释量 R²	显著度 p
油松	南	水汽压亏缺 D (kPa)	J_s = 0.0028 + 0.0021lnD	0.569	< 0.000 1
P. tabulaeformis	South	总辐射R_s (W·m^-2)	J_s = 0.0007 + 9e - 6R_s	0.707	< 0.000 1
	北	水汽压亏缺 D (kPa)	J_s = 0.0025 + 0.00019lnD	0.555	< 0.000 1
	North	总辐射R_s (W·m^-2)	J_s = 0.0006 + 8e - 6R_s	0.682	< 0.000 1
雪松	东	水汽压亏缺 D (kPa)	J_s = 0.002 + 0.0014lnD	0.364	< 0.000 1
C. deodara	East	总辐射R_s (W·m^-2)	J_s = 0.0008 + 6e - 6R_s	0.562	< 0.000 1
	南	水汽压亏缺 D (kPa)	J_s = 0.0026 + 0.0019lnD	0.447	< 0.000 1
	South	总辐射R_s (W·m^-2)	J_s = 0.0009 + 8e - 6R_s	0.655	< 0.000 1
	西	水汽压亏缺 D (kPa)	J_s = 0.002 + 0.0015lnD	0.410	< 0.000 1
	West	总辐射R_s (W·m^-2)	J_s = 0.0007 + 6e - 6R_s	0.609	< 0.000 1
	北	水汽压亏缺 D (kPa)	J_s = 0.0023 + 0.0018lnD	0.460	< 0.000 1
	North	总辐射R_s (W·m^-2)	J_s = 0.0008 + 7e - 6R_s	0.642	< 0.000 1
刺槐	东	水汽压亏缺 D (kPa)	J_s = 0.0022 + 0.0014lnD	0.565	< 0.000 1
R. pseudoacacia	East	总辐射R_s (W·m^-2)	J_s = 0.0008 + 6e - 6R_s	0.679	< 0.000 1
	南	水汽压亏缺 D (kPa)	J_s = 0.0021 + 0.0013lnD	0.515	< 0.000 1
	South	总辐射R_s (W·m^-2)	J_s = 0.0008 + 6e - 6R_s	0.636	< 0.000 1
	西	水汽压亏缺 D (kPa)	J_s = 0.0023 + 0.0015lnD	0.535	< 0.000 1
	West	总辐射R_s (W·m^-2)	J_s = 0.0009 + 6e - 6R_s	0.618	< 0.000 1
	北	水汽压亏缺 D (kPa)	J_s = 0.0021 + 0.0013lnD	0.493	< 0.000 1
	North	总辐射R_s (W·m^-2)	J_s = 0.0009 + 6e - 6R_s	0.597	< 0.000 1

表4 2008年6月到11月油松、雪松、刺槐不同方位树干液流与水汽压亏缺、总辐射之间的曲线拟合结果

物种 Species	方位 Orientation	环境因子 Environmental factors	方程 Equation	解释量 R²	显著度 p
油松	南	水汽压亏缺 D (kPa)	J_s = 0.0028 + 0.0021lnD	0.569	< 0.000 1
P. tabulaeformis	South	总辐射R_s (W·m^-2)	J_s = 0.0007 + 9e - 6R_s	0.707	< 0.000 1
	北	水汽压亏缺 D (kPa)	J_s = 0.0025 + 0.00019lnD	0.555	< 0.000 1
	North	总辐射R_s (W·m^-2)	J_s = 0.0006 + 8e - 6R_s	0.682	< 0.000 1
雪松	东	水汽压亏缺 D (kPa)	J_s = 0.002 + 0.0014lnD	0.364	< 0.000 1
C. deodara	East	总辐射R_s (W·m^-2)	J_s = 0.0008 + 6e - 6R_s	0.562	< 0.000 1
	南	水汽压亏缺 D (kPa)	J_s = 0.0026 + 0.0019lnD	0.447	< 0.000 1
	South	总辐射R_s (W·m^-2)	J_s = 0.0009 + 8e - 6R_s	0.655	< 0.000 1
	西	水汽压亏缺 D (kPa)	J_s = 0.002 + 0.0015lnD	0.410	< 0.000 1
	West	总辐射R_s (W·m^-2)	J_s = 0.0007 + 6e - 6R_s	0.609	< 0.000 1
	北	水汽压亏缺 D (kPa)	J_s = 0.0023 + 0.0018lnD	0.460	< 0.000 1
	North	总辐射R_s (W·m^-2)	J_s = 0.0008 + 7e - 6R_s	0.642	< 0.000 1
刺槐	东	水汽压亏缺 D (kPa)	J_s = 0.0022 + 0.0014lnD	0.565	< 0.000 1
R. pseudoacacia	East	总辐射R_s (W·m^-2)	J_s = 0.0008 + 6e - 6R_s	0.679	< 0.000 1
	南	水汽压亏缺 D (kPa)	J_s = 0.0021 + 0.0013lnD	0.515	< 0.000 1
	South	总辐射R_s (W·m^-2)	J_s = 0.0008 + 6e - 6R_s	0.636	< 0.000 1
	西	水汽压亏缺 D (kPa)	J_s = 0.0023 + 0.0015lnD	0.535	< 0.000 1
	West	总辐射R_s (W·m^-2)	J_s = 0.0009 + 6e - 6R_s	0.618	< 0.000 1
	北	水汽压亏缺 D (kPa)	J_s = 0.0021 + 0.0013lnD	0.493	< 0.000 1
	North	总辐射R_s (W·m^-2)	J_s = 0.0009 + 6e - 6R_s	0.597	< 0.000 1

图5 油松3号不同深度的树干液流特征。 A, 2008年8月3日油松3号北向不同深度树干液流密度的日变化。B, 15 mm深处液流密度(x轴)与75 mm深处液流密度(y轴)之间的线性关系, 箭头指向时滞方向。

Fig. 5 Characteristics of sap flux density (Js) at different depths in Pinus tabulaeformis trees. A, Diurnal variation in Js on the north aspect with two depths in Pinus tabulaeformis No. 3 tree on 3th, August, 2008. B, Linear relationships between Js at depth of 15 mm (x-axis) and Js at depth of 75 mm (y-axis). Arrows point to the time lag.

图6 雪松3号不同方向和不同深度的树干液流特征。 A-D, 2008年8月3日雪松3号东南西北向两个深度树干液流密度的日变化。E-H, 15 mm深处液流密度(x轴)与75 mm深处液流密度(y轴)之间的线性关系, 箭头指向时滞方向。

Fig. 6 Characteristics of sap flux density (Js) at different depths at four aspects in Cedrus deodara No. 3. A-D, Diurnal variation in Js at four aspects with two depths in Cedrus deodara No. 3 tree on 3rd, August, 2008. E-H, Linear relationships between Js at depth of 15 mm (x-axis) and Js at depth of 75 mm (y-axis). Arrows point to the time lag.

表5 7月到11月油松、雪松15 mm和75 mm深处的树干液流之间的曲线拟合

Table 5 Curve estimation between sap flux density (Js) between Js at depth of 15 mm and Js at depth of 75 mm in Pinus tabulaeformis and Cedrus deodara from July to November

物种 Species	深度 Depth	方程 Equation	解释量 R²	显著度 p
油松 Pinus tabulaeformis	15 mm vs 75 mm	J_s-75mm = 4e - 5 + 0.149J_s-15mm	0.943	< 0.000 1
雪松 Cedrus deodara	15 mm vs 75 mm	J_s-75mm = 2e - 5 + 0.105J_s-15mm	0.889	< 0.000 1

表6 7月到11月油松、雪松15 mm、75 mm深度树干液流与水汽压亏缺、总辐射之间的曲线拟合

Table 6 Curve estimation between sap flux density (Js) at depth of 15 mm, 75 mm and vapor pressure deficit (D), total radiation (Rs) in Pinus tabulaeformis and in Cedrus deodara from July to November

物种 Species	深度 Depth	环境因子 Environmental factors	方程 Equation	解释量 R²	显著度 p
油松 Pinus tabulaeformis	15 mm	水汽压亏缺 D (kPa)	J_s-15cm = 0.004 + 0.0029lnD	0.607	< 0.000 1
油松 Pinus tabulaeformis		总辐射R_s (W·m^-2)	J_s-15cm = 0.0009 + 1e - 5R_s	0.664	< 0.000 1
	75 mm	水汽压亏缺 D (kPa)	J_s-75cm = 0.0006 + 0.0004lnD	0.541	< 0.000 1
		总辐射R_s (W·m^-2)	J_s-75cm = 0.0002 + 2e - 6R_s	0.584	< 0.000 1
雪松 Cedrus deodara	15 mm	水汽压亏缺 D (kPa)	J_s-15cm = 0.003 + 0.002 1lnD	0.570	< 0.000 1
雪松 Cedrus deodara		总辐射R_s (W·m^-2)	J_s-15cm = 0.0007 + 9e - 6R_s	0.674	< 0.000 1
	75 mm	水汽压亏缺 D (kPa)	J_s-75cm = 0.0003 + 0.0002lnD	0.546	< 0.000 1
		总辐射R_s (W·m^-2)	J_s-75cm = 1e - 4 + 1e - 6R_s	0.626	< 0.000 1

图7 液流的空间变异对整树蒸腾造成的误差。 A, 油松、雪松和刺槐树干液流的方位变异对整树蒸腾造成的误差。B, 油松或者雪松树干液流的径向变异对整树蒸腾造成的误差。

Fig. 7 Error to whole-tree transpiration caused by spatial variation. A, Error to whole-tree transpiration caused by axial variation of sap flux density (Js) on different orientation in Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia. B, Error to whole-tree transpiration caused by radial variation of Js at different depth in Pinus tabulaeformis, Cedrus deodara and Robinia pseudoacacia.

图8 DOY210到DOY213期间雪松3号东南西北向15 mm和75 mm深度树干液流密度的日变化。 A, 雪松3号东南西北向15 mm深处树干液流密度的日变化。B, 雪松3号东南西北向75 mm深处树干液流密度的日变化。

Fig. 8 Diurnal variation in sap flux density (Js) at four aspects with two depths in Cedrus deodara No. 3 from DOY210 to DOY213. A, Diurnal variation in Js at four aspects at the depth of 15 mm in Cedrus deodara No. 3. B, Diurnal variation in Js at four aspects at the depth of 75 mm in Cedrus deodara No. 3.

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