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Variability in energy partitioning and resistance parameters for a vineyard in northwest China


Agricultural Water Management 96 (2009) 955–962

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Agricultural Water Management
journal homepage: www.elsevier.com/locate/agwat

Variability in energy partitioning and resistance parameters for a vineyard in northwest China
Sien Li a, Ling Tong a,*, Fusheng Li b, Lu Zhang c, Baozhong Zhang a, Shaozhong Kang a
a

Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China Agricultural College, Guangxi University, Nanning, Guangxi 530005, China c CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia
b

A R T I C L E I N F O

A B S T R A C T

Article history: Received 27 June 2008 Accepted 14 January 2009 Available online 7 February 2009 Keywords: Bowen ratio Eddy covariance Semiarid and arid regions Surface resistance Vineyard

Grapevines are extensively grown in the semiarid and arid regions, but little information is available on the variability of energy partitioning and resistance parameters for the vineyard. To address this question, an eddy covariance system was applied to measure energy balance over a vineyard in northwest China during 2005–2006. Result indicated that 2-year average Bowen ratio (b) of vineyard was 1.0, canopy resistance (rc) 289.3 s m?1, aerodynamic resistance (ra) 9.7 s m?1 and climatological resistance (ri) 117 s m?1. This implied that the annual energy was split almost equally between sensible heat and latent heat. Compared to the corresponding values in other ecosystems reported by Wilson et al. [Wilson, K.B., Baldocchi, D.D., Aubinet, M., Berbigier, P., Bernhofer, C., Dolman, H., Falge, E., Field, C., Goldstein, A., Granier, A., Grelle, A., Halldor, T., Hollinger, D., Katul, G., Law, B.E., Lindroth, A., Meyers, T., Moncrieff, J., Monson, R., Oechel, W., Tenhunen, J., Valentini, R., Verma, S., Vesala, T., Wofsy, S., 2002. Energy partitioning between latent and sensible heat ?ux during the warm season at FLUXNET sites. Water Resource Research 38, 1294–1305.], the vineyard had a higher b, rc and ri than deciduous forests, corn and soybean, and grassland. Such difference was mainly attributed to (1) serious water stress in 2005, which resulted in a greater rc up to 364.4 s m?1; (2) sparse canopy with row spacing of 2.9 m and plant spacing of 1.8 m; (3) warm-dry climate and high attitude (1581 m) along with higher ri and lower psychrometer (54 Pa K?1) in the arid region of northwest China. These characters of vineyard revealed varying process of energy partitioning and surface resistance, and provided a scienti?c basis in understanding and modeling water and energy balance for the vineyard in the semiarid and arid regions. Crown Copyright ? 2009 Published by Elsevier B.V. All rights reserved.

1. Introduction Grapevines are extensively grown in the semiarid and arid regions owing to its high economical and nutritive value and strong drought tolerance. Generally, the vineyard has three important features: (1) it usually has tall plants and widely spaced rows. Wide row spacing increased the contribution of soil evaporation to the vineyard evapotranspiration, and sparse canopy may also add the dif?cult to accurately quantify water and energy exchange over the canopy. (2) It always has trellis wires, which alter the distribution of net radiation in the vineyard and change the canopy and soil energy balance (Heilman et al., 1996). (3) Grapevine has a higher drought resistant ability and lower water demand relative to other crops, e.g. maize and wheat, thus it has been widely planted in the water scarcity region. Although

* Corresponding author. Fax: +86 10 62737611. E-mail addresses: tongling2001@tom.com (L. Tong), lpfu6@163.com (F. Li).

accurately quantifying the energy partitioning process of vineyard is dif?cult for its previous features, it is critical for understanding the hydrological cycle and energy balance in the vineyard. Several researchers have investigated the characters of energy partitioning and transport in the vineyard. Hicks (1973) reported that a strong sensible heat advection transported from soil surface to canopy in a warm vineyard in Australia. Oliver and Sene (1992) indicated that grapevines and soil could be treated as independent systems with little energy transport between them. Heilman et al. (1994) showed that the sensible heat from the exposed soil is a major contributor to canopy energy balance and transpiration. Heilman et al. (1996) examined the effect of trellising on energy balance of a vineyard, and indicated that the canopy net radiation and transpiration were substantially higher for the open hedgerows in 1993 relative to the value for the dense hedgerows in 1992, but little effect was presented on vineyard net radiation and evapotranspiration across the both years. Yunusa et al. (2004) studied the energy components over the warm-dry period and cool-humid period in eastern Australia. The ratio of latent heat ?ux

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to available energy increased from 0.47 in warm-dry period to 0.57 in cool-humid period. This increase was associated with a reduced vapor pressure de?cit that enhanced dissipation of energy absorbed by canopy as evapotranspiration through the canopy. The previous studies provided useful information on water and energy exchange in soil–vineyard–atmosphere system, but little information was presented on seasonal and annual variability in the long-term Bowen ratio over the vineyard canopy. How the energy partitions between the latent and sensible heat ?uxes during a long term in this ecosystem remains unanswered to the hydrologist and agro-meteorologist. Additionally, studying on the surface resistance is important to quantify Bowen ratio and simulate water and heat transports. How the surface resistance parameters of the vineyard varied on seasonal or annual scales is still unclear and of interest for the investigator. Furthermore, Wilson et al. (2002) listed mean Bowen ratio value of many ecosystems using the eddy covariance data from FLUXNET, but the information about the vineyard Bowen ratio was not included. Thus it is necessary to extend the work of Wilson et al. (2002). Therefore, we conducted a 2-year experiments using eddy covariance over a vineyard in arid region of northwest China so as to (1) examine diurnal, seasonal and annual variation of vineyard Bowen ratio; (2) reveal variation pattern of surface resistances over the growing season; and (3) quantify the effect of surface resistance on energy partitioning. 2. Materials and methods 2.1. Experimental site and design Field experiment was conducted at Shiyanghe Experimental Station for Water-saving in Agriculture and Ecology of China Agricultural University in 2005 and 2006. The experimental site was located in Wuwei City, Gansu Province, in the border of Tenger Desert (N378520 2000 , E1028500 5000 , altitude 1581 m). The site is in a typical continental temperate climate zone with a mean annual temperature of 8 8C, annual accumulated temperature (>0 8C) of 3550 8C. Mean annual precipitation is 164 mm and pan evaporation is 2000 mm. Average annual sunshine duration is 3000 h with over 150 frost-free days. Groundwater table is 25–30 m below the ground surface and soil is light sandy loam texture. Four-year old grapevines were grown with row spacing of 290 cm and plant spacing of 180 cm in an area of 10,177.5 m2 (177 m ? 57.5 m). The average canopy height was about 1.5 m in the maturity growth stage. The experimental vineyard was irrigated four times during the whole growing stage, with irrigation dates of 10 May, 26 May, 12 June and 1 July 2005 and irrigation amount of 15, 15, 20 and 20 mm, respectively. In 2006, the vineyard was also irrigated four times, with irrigation date of 5 May, 28–29 May, 29 June and 9–10 August and an irrigation amount of 41.7 mm for each supply. Precipitation during the whole growing stage was 70 mm in 2005 and 177 mm in 2006. 2.2. Eddy covariance measurements An open-path eddy covariance system was installed near the central of vineyard. The sensor height was 0.8 m above the top of the canopy in accordance with available fetch (80 m). The eddy covariance system consisted of a 3D sonic anemometer/thermometer (model CSAT3, Campbell Scienti?c Inc., Logan, UT, USA), a Krypton hygrometer (KH20, Campbell Scienti?c Inc., USA) and a temperature and humidity sensor (model HMP45C). Model CSAT3 and KH20 measured vertical ?uctuations of wind, sonic temperature and water vapor density at 0.1 s interval, and the sensors were 20 cm apart. Temperature and humidity sensor can measure mean air temperature and vapor pressure de?cit for 10 min periods. All

the sensors were connected to a datalogger (model CR5000, Campbell Scienti?c Inc., Logan, UT, USA), and the statistics (average, variance and covariance) were computed for 10 min periods. Measurements were made continuously during the period of 16 April to 10 September in 2005 and 30 April to 7 October in 2006. Latent and sensible heat ?uxes were calculated by eddy covariance (Baldocchi, 2003):

lET ? ra lw0 q0
H ? C p ra w0 T 0

(1) (2)

where lET and H are the latent and sensible heat ?ux (W m?2), w0 q0 the covariance between ?uctuations of vertical wind speed w0 (m s?1) and humidity q0 (kg kg?1), w0 T 0 the covariance between ?uctuations of w0 and sonic temperature T0 (K), ra the air density (kg m?3), Cp the speci?c heat of dry air at constant pressure (J kg?1 K?1), l the latent heat of water vaporization, and ET is the crop evapotranspiration (kg m?2 s?1). The corrections to open-path eddy covariance measurements include: (1) choice of 10-min interval for eddy ?ux computation (Twine et al., 2000); (2) the signal asynchrony correction; (3) the oxygen-correction proposed by Tanner and Greene (1989); (4) planar ?t method used for coordinate rotation (Paw et al., 2000; Finnigan et al., 2003); (5) density correction according to the method of Webb et al. (1980); and (6) data gaps ?lled using the MDV (mean diurnal variation) method (Falge et al., 2001). Sum of (lET + H) accounts for about 78% of the available energy over whole experimental period. The assessment of energy balance closure has been conducted in Li et al. (2008) in detail. 2.3. Other measurements Net radiation (Rn) was measured by a net radiometer (model Q7.1) at the same height above the vegetation surface as the integrated temperature-humidity probe. The radiometer was calibrated by a high precision albedometer (model CM7B, Kipp & Zonen, Delft, The Netherlands) and a net pyrgeometer (model CG2, Kipp & Zonen, Delft, The Netherlands) before the experiment. Two soil heat ?ux plates (model HFP01, Hukse?ux, The Netherlands) were inserted below 80 mm soil depth, which were respectively located between the inter-row and inter-plant. Surface soil heat ?ux was calculated by correcting the heat ?ux at 80 mm for heat storage above the transducers, determined by change in soil temperature of the soil volume above the heat ?ux transducers. Temperature above the soil heat ?ux plates was measured with four pairs of thermocouples (model 105T, Campbell Scienti?c, USA) at depths of 20 and 60 mm in two positions in line with every soil heat ?ux plate. All the sensors were sampled 10 min averages of net radiation and soil heat ?ux, which were calculated and stored in the datalogger. Daily reference crop evapotranspiration (ET0), short wave net radiation (Rs) and precipitation were determined by an automatic weather station located at the north of the vineyard. Measurements were continuously made during the period of 16 April to 7 October in 2005 and 15 April to 7 October 2006. 2.4. Computation of Bowen ratio and surface resistance parameters The Bowen ratio is de?ned as (Wilson et al., 2002):

b?

H

lET

(3)

where lET and H are the latent and sensible heat ?ux determined by eddy covariance (W m?2). According to Wilson et al. (2002), the

S. Li et al. / Agricultural Water Management 96 (2009) 955–962

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Bowen ratio can also be expressed as

3. Results and discussion (4) 3.1. Diurnal variation of Bowen ratio Fig. 1 indicates the diurnal variation of Bowen ratio under different soil moisture condition. When the soil moisture was higher and adequate water can be supplied to the grapevine (Fig. 1(a)), b showed a regular parabolic trend during daytime and it was nearly constant over the period of 10:00–17:00 h. However, b presented a ‘‘L’’ shape in the daytime under the water de?cit condition (Fig. 1(b)). And b increased or decreased signi?cantly during the daytime. Such result may be due to that the canopy has an ability to maintain the constant ratio of energy partitioning when wet soil can supply adequate water to meet grapevine requirement. However, the canopy reduced stomatal aperture to restrict water loss in the drought soil, then the partitioning of available energy into sensible heat ?ux increased signi?cantly. Fig. 2 shows the diurnal variation of b under different weather condition. b was nearly constant at the midday of clear day (Fig. 2(a)). However, b varied with the change of net radiation in a cloudy day though net radiation shows an unexpected change (Fig. 2(b)). Crago (1996) indicated that the canopy has an ability to keep evaporative fraction (ratio of latent heat ?ux to available energy) constant during the sunny days, which was similar to our result. But our study still demonstrated that the conservative of b or evaporative fraction depended on the weather condition and soil moisture. As shown in Figs. 1 and 2, it can be concluded that net radiation and soil wetness are two key factors affecting the diurnal behavior of b in the vineyard.

b?

1 ? r c =r a ? r i =r a D=r ? ri =ra

where rc is the canopy resistance (s m?1), ra the aerodynamic resistance (s m?1), ri the climatological resistance (s m?1), D the slop of the saturation vapor pressure curve with respect to temperature at a speci?ed temperature (Pa K?1), and r is the psychrometer constant. The ra was calculated between the top of grapevine canopy and the observation point of eddy covariance above the canopy, following Rana and Katerji (2008): ra ? 1 k u?
2

In

z?d hc ? d

(5)

where z is the observation point of eddy covariance, d the zero plane displacement (m), is estimated by d = 0.67hc, with hc the mean height of grapevine canopy (m), k the Karman constant and u* is the friction velocity (m s?1) which measured by eddy covariance. The climatological resistance (ri) is ri ?

rC p VPD r?Rn ? G?

(6)

Based on the calculation of b, ra and ri, rc can be calculated by rearranging Eq. (4):   D ri rc ? b ? (7) ra ? ri ? ra r ra

Fig. 1. Diurnal variation of Bowen ratio under different soil moisture condition. When u exceeds 60% of uf, adequate water can be provided to the crop, otherwise there exists water de?cit in the ?eld. Symbols: b, Bowen ratio; uf, ?eld water capacity; u, volumetric soil moisture.

Fig. 2. Diurnal variation of Bowen ratio under different weather condition. (a) Clear day and (b) cloudy day. Symbols: b, Bowen ratio; Rn, net radiation.

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S. Li et al. / Agricultural Water Management 96 (2009) 955–962 Table 1 The values of meteorological parameters. Parameter Unit May 2005 ET0 Rs Rn Precipitation Irrigation Ta Wind speed VPD mm month W m?2 W m?2 mm mm 8C m s?1 kPa
?1

959

June 2006 111.5 518.0 345.2 30.0 83.4 19.4 1.7 1.7 2005 131.0 588.1 335.5 4.0 20.0 25.0 1.2 2.1 2006 122.4 569.4 376.9 3.0 41.7 24.7 1.3 2.1

July 2005 102.7 458.3 298.4 16.0 20.0 25.6 1.1 2.0 2006 98.5 421.1 328.3 91.0 24.4 1.2 1.6

August 2005 97.1 412.9 309.8 30.0 24.0 1.1 1.6 2006 93.1 412.3 344.1 36.0 41.7 24.6 1.1 1.7

September 2005 60.9 315.2 21.0 2006 59.3 331.9 271.2 17.0 18.5 1.1 1.2

121.6 574.3 342.4 19.0 30.0 20.4 1.5 1.7

3.2. Seasonal variation of Bowen ratio In order to investigate the seasonal variation of b in 2005 and in 2006, it is necessary to present the variation of meteorological and soil parameters in both years. Fig. 3(a) shows the variation trend of ET0 in 2005 and 2006. Daily ET0 ranged from 0.5 to 6 mm, and it generally increased from April to June, peaked in June, and then decreased from June to September in both years. Total ET0 in different months were listed in Table 1. It can be seen that the monthly ET0 was higher in 2005 than in 2006, indicating that the potential atmosphere evaporation was greater in 2005. Fig. 3(b) shows that daily Rs gradually increased from April to June, and then slightly decreased from June to September in both years. Monthly averaged Rs was slightly higher in 2005 than in 2006 from May to August, but lower in September (Table 1). Total precipitation during May–September was 90 mm in 2005, and 177 mm in 2006. Thus year 2005 was an insuf?cient water-supply year, while year 2006 a plentiful water-supply year. Total irrigation and precipitation in 2005 was 160 mm from May to September, but its corresponding value in 2006 is 348.8 mm. Variations of wind speed, air temperature, vapor pressure de?cit, and soil moisture were also depicted in Fig. 3. Fig. 4(a) presents that b varied from ?1 to 6, and it decreased from April to June, was nearly constant during June to August, and went up slightly in September in both years. It also indicated that b was higher in 2005 than in 2006, with averaged b of 1.2 in 2005 and 0.8 in 2006, respectively (Table 2). Compared to the other ecosystems, Wilson et al. (2002) reported that mean b for coniferous forests in Mediterranean climate, coniferous forests, tundra, grasslands, deciduous forests and crops sites were 17.9, 1.07, 0.99, 0.89, 0.42 and 0.31, respectively. In our study, 2-year average b of the vineyard was approximately equal to 1, which is lower than the coniferous forests in the Mediterranean climate, close to the coniferous forests and tundra, but signi?cantly greater than the deciduous forests and crops sites. The high b in the vineyard can be explained by the following reasons: (1) Serious drought occurred in 2005 signi?cantly increased the energy partitioning into sensible heat ?ux. (2) The vineyard belongs to typical sparse canopy with row spacing of 2.9 m and plant spacing of 1.8 m. And its LAI (leaf area index) varied from 0 to 3. (3) The warm-dry climate also resulted in stomatal restraint on crop transpiration and higher canopy resistance. Moreover, the variability of b over vegetation types can be quanti?ed by the surface resistance parameters (Wilson et al., 2002), which will be analyzed in the following section. When compared to the vineyards in other regions, Heilman et al. (1996) investigated daytime energy components of a vineyard over the period of Days 152–159 in 1992 and Days

155–163 in 1993, indicating the average b over the two periods was 0.33 and 0.76, respectively. Yunusa et al. (2004) compared the energy balance components of a drip-irrigated vineyard for the warm-dry days in mid-February (Period 1) and the cool-humid days in late March (Period 2), mean b during the two stages was 1.10 and 0.76, respectively. However, these studies only report the energy partitioning over a short-term period, which is different from a relatively long-term period in our study. But these investigations all revealed that great variability in b often exists above the sparse canopy and the energy partitioning processes are affected by other environmental factors, e.g. climate factor and irrigation. Fig. 4(b) depicts the seasonal variation of canopy resistance (rc). rc ranged from 0 to 1000 s m?1 over both seasons; rc was higher in the ?rst 2-month period than in the last 3-month. Fig. 4(b) also illustrated that rc was signi?cantly higher in 2005 than in 2006, with annual average of 364.4 and 214.2 s m?1 in both years, respectively. Wilson et al. (2002) illustrated mean rc for the coniferous forests in Mediterranean climate, grasslands, coniferous forests, deciduous forest, tundra, and crops sites were 654, 244, 120, 72, 71, and 60 s m?1, respectively. Thus vineyard rc was only lower than the coniferous forests in Mediterranean climate, close to the grasslands, but signi?cantly greater than the other ecosystems. As for the vineyard in eastern Australia, Yunusa et al. (2004) indicated that the daily average rc values were 840 and 410 s m?1 during the warm-dry and cool-humid periods, respectively. In the humid-dry day, rc exceeded 1000 s m?1 in the morning. According to the results of Yunusa et al. (2004) and this study, it can be concluded that the sparse vineyard generally has a higher rc, especially during the warm-dry days. Fig. 4(c) indicates that the climatological resistance (ri) ranged from 0 to 300 s m?1, and seasonal variations were not found signi?cantly in both years. Annual ri was 119.4 and 114.4 s m?1 in both years, respectively (Table 2). Wilson et al. (2002) reported that mean ri for the coniferous forests in Mediterranean climate, grasslands, coniferous forests, crops sites, deciduous forest and tundra were 66, 65, 43, 40, 37 and 26 s m?1. Our results were signi?cantly higher than the previous values. Such difference was mainly attributed to the warm-dry climate, high attitude (altitude 1581 m), low air pressure (about 85 kPa) and low psychrometric constant (0.054 kPa 8C?1) in the arid region of northwest China. In addition, time period is different in both studies. Our study selected the period of 10:00–17:00 (local standard time) to calculate daytime average value while Wilson et al. (2002) selected the period of 10:00–14:30 (local standard time) to calculate the value. Fig. 4(d) shows that the aerodynamic resistance (ra) ranged from 0 to 20 s m?1, and seasonal variations were not found signi?cantly in both years, too.

Fig. 3. Seasonal variation of meteorological and soil parameters in 2005 and 2006. Symbols: ET0, reference crop evapotranspiration; Rs, net short wave radiation, VPD, water vapor pressure de?cit.

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Fig. 4. Seasonal variation of Bowen ratio (a), canopy resistance (b), climatological resistance (c), and aerodynamic resistance (d) in 2005 and in 2006. Symbols: b, Bowen ratio; rc, canopy resistance; ri, climatological resistance; ra, aerodynamic resistance.

3.3. Response of Bowen ratio to surface resistance parameters Fig. 5(a) indicates that there existed a strong linear relationship between b and rc (R2 = 0.70), e.g. b increased signi?cantly along with the increased rc. rc has great effect on the variability of energy partitioning, which has been demonstrated by many researchers (Wilson et al., 2002; Yunusa et al., 2004). Fig. 5(b) shows an
Table 2 Annual average values of Bowen ratio (b), surface resistances (rc, ra, and ri) and total precipitation and irrigation (P + I). Annual average b and resistances were calculated by averaged the daily value. Year 2005 2006

b
1.2 0.8

rc (s m?1) 364.4 214.2

ra (s m?1) 9.3 10.0

ri (s m?1) 119.4 114.4

P + I (mm) 140.0 343.8

approximately decreasing trend of b along with the increase of ri. Fig. 5(c) indicates a weak correlation between b and ra. Wilson et al. (2002) analyzed the effect of the resistance terms on energy partitioning, focused on the role of rc and ri but not ra, because the evaporation and b are less sensitive to ra. Our result was similar to the conclusion of Wilson et al. (2002). Fig. 5(d) shows the relationship between rc/ra and ri/ra over both seasons, it can be seen that rc/ra was linearly correlated with ri/ra. rc/ra ranged from 0 to 100 while ri/ra from 0 to 30. Katerji and Rana (2006) applied an empirical equation to calculate rc, which was rc/ ra = a. (r*/ra) + b, where a and b are the empirical calibration coef?cients determined by the experiment, r* is the climatic resistance containing temperature (r* = (D + r)*ri/D, D is the slope of the saturation pressure de?cit versus temperature, and r is the psychrometric constant). The relationship was con?rmed over many crop types, e.g. grass, wheat, rice, alfalfa, tomato,

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Fig. 5. Relationship between Bowen ratio and canopy resistance (a), climatological resistance (b), and aerodynamic resistance (c). And the relationship between rc/ra (the ratio of canopy resistance to aerodynamic resistance) and ri/ra (the ratio of climatological resistance to aerodynamic resistance) (d).

drip-irrigated vineyard, soybean, etc. (Katerji and Rana, 2006; Rana and Katerji, 2008). In this study, a linear relationship between rc/ra and ri/ra also existed over the furrow-irrigated vineyard, which was in line with the results of Katerji and Rana (2006) and Rana and Katerji (2008), despite that this study adopt ri but not r*. Our result indicates that using this empirical canopy resistance equation to simulate the evapotranspiration for the furrow-irrigated vineyard is feasible. 4. Conclusions The following conclusions can be drawn from this study: (1) Daily b, rc, ri and ra varied from ?1 to 6, 0 to 1000 s m , 0 to 200 s m?1 and 0 to 20 s m?1, with 2-year average value of 1, 289.3, 117 and 9.7 s m?1, respectively. Compared to the other ecosystems, e.g. deciduous forests, corn and soybean, and grassland, the vineyard had higher b, rc and ri. (2) On daily scale, soil wetness and net radiation affected the diurnal variation of b signi?cantly. On seasonal scale, the variability of b can be quanti?ed by rc, ra and ri. rc can account for 70% of b, but b was less sensitive to the change of ra. On annual scale, b varied from 1.2 in 2005 to 0.8 in 2006. (3) A linear relationship between rc/ra and ri/ra was found in the furrow-irrigated vineyard, which provides an empirical equation to calculate rc. In summary, the vineyard had high b, rc and ri and the available energy was almost equally partitioned between the sensible and latent ?ux on the seasonal basis. The variability in vineyard b can be explained by the variation of rc. These results may provide
?1

scienti?c basis in understanding and modeling energy transport over the vineyard in the arid region of northwest China. Acknowledgements The research was ?nancially supported by Chinese National Natural Science Fund (50679081, 40771034, 50869001), National High Tech Research Plan (2006AA100203) and PCSIRT (IRT0657). We would like to think the anonymous reviewers for their constructive comments. References
Baldocchi, D.D., 2003. Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future. Global Change Biology 9, 479–492. Crago, R.D., 1996. Conservation and variability of the evaporative fraction during the daytime. Journal of Hydrology 180, 173–194. Falge, E., Baldocchi, D.D., Olson, R., Anthoni, P., Aubinet, M., Bernhofer, C., Burba, G., ¨ Ceulemans, R., Clement, R., Dolman, H., Granier, A., Gross, P., Grunwald, T., Hollinger, D., Jensen, N.-O., Katul, G., Keronen, P., Kowalski, A., Ta Lai, C., Law, ¨ B.E., Meyers, T., Moncrieff, J., Moors, E., Munger, J.W., Pilegaard, K., Rannik, U., Rebmann, C., Suyker, A., Tenhunen, J., Tu, K., Verma, S., Vesala, T., Wilson, K., Wofsy, S., 2001. Gap ?lling strategies for long term energy ?ux data sets. Agricultural and Forest Meteorology 107, 71–77. Finnigan, J.J., Clement, R., Malhi, Y., Leuning, R., Cleugh, H.A., 2003. A re-evaluation of long-term ?ux measurement techniques. Part I. Averaging and coordinate rotation. Boundary-Layer Meteorology 107, 1–48. Heilman, J.L., McInnes, K.J., Savage, M.J., Gesch, R.W., Lascano, R.J., 1994. Soil and canopy energy balances in a west Texas vineyard. Agricultural and Forest Meteorology 71, 99–114. Heilman, J.L., McInnes, K.J., Gesch, R.W., Lascano, R.J., Savage, M.J., 1996. Effects of trellising on the energy balance of a vineyard. Agricultural and Forest Meteorology 81, 79–83. Hicks, B.B., 1973. Eddy ?uxes over a vineyard. Agricultural and Forest Meteorology 12, 203–215.

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S. Li et al. / Agricultural Water Management 96 (2009) 955–962 Twine, T.E., Kustas, W.P., Norman, J.M., Cook, D.R., Houser, P.R., Meyers, T.P., Prueger, J.H., Starks, P.J., Wesely, M.L., 2000. Correcting eddy-covariance ?ux underestimates over a grassland. Agricultural and Forest Meteorology 103, 279–300. Webb, E.K., Pearman, G.I., Leuning, R., 1980. Correction of ?ux measurements for density effects due to heat and water vapor. Quarterly Journal of the Royal Meteorological Society 106, 85–100. Wilson, K.B., Baldocchi, D.D., Aubinet, M., Berbigier, P., Bernhofer, C., Dolman, H., Falge, E., Field, C., Goldstein, A., Granier, A., Grelle, A., Halldor, T., Hollinger, D., Katul, G., Law, B.E., Lindroth, A., Meyers, T., Moncrieff, J., Monson, R., Oechel, W., Tenhunen, J., Valentini, R., Verma, S., Vesala, T., Wofsy, S., 2002. Energy partitioning between latent and sensible heat ?ux during the warm season at FLUXNET sites. Water Resource Research 38, 1294–1305. Yunusa, I.A.M., Walker, R.R., Lu, P., 2004. Evapotranspiration components from energy balance, sap?ow and microlysimetry techniques for an irrigated vineyard in inland Australia. Agricultural and Forest Meteorology 127, 93–107.

Katerji, N., Rana, G., 2006. Modelling evapotranspiration of six irrigated crops under Mediterranean climate conditions. Agricultural and Forest Meteorology 138, 142–155. Li, S.E., Kang, S.Z., Li, F.S., Zhang, L., Zhang, B.Z., 2008. Vineyard evaporative fraction based on eddy covariance in an arid desert region of Northwest China. Agricultural Water Management 95, 937–948. Oliver, H.R., Sene, K.J., 1992. Energy and water balances of developing vines. Agricultural and Forest Meteorology 61, 167–185. Paw, U.K.T., Baldocchi, D.D., Meyers, T.P., Wilson, K.B., 2000. Correction of eddy covariance measurements incorporating both advective effects and density ?uxes. Boundary-Layer Meteorology 97, 487–511. Rana, G., Katerji, N., 2008. Direct and indirect methods to simulate the actual evapotranspiration of an irrigated overhead table grape vineyard under Mediterranean conditions. Hydrological Processes 22, 181–188. Tanner, B.D., Greene, J.P., Measurement of Sensible Heat and Water-vapor Fluxes using Eddy-correlation Methods. Final Report Prepared for U.S Army Dugway Proving Grounds, U.S. Army, Dugway, Utah, 1989, 17 p.


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30.3 Performance Variability of a 90GHz Static ...The variation of critical circuit parameters for ... voltage, parasitic capacitance, and resistance. ...
...VARIABILITY FOR YIELD PARAMETERS AND RUST RESISTANCE IN F2....unkown
(Supplement on Genetics and Plant Breeding) www.thebioscan.in GENETIC VARIABILITY FOR YIELD PARAMETERS AND RUST RESISTANCE IN F2 POPULATION OF WHEAT (...
VARIABILITY OF RESISTANCE TO NATURAL HAEMONCHUS CONTORTUS ....unkown
www.animalmedicalresearch.org VARIABILITY OF RESISTANCE TO NATURAL HAEMONCHUS CONTORTUS INFECTION VIS-A-VIS HAEMATOLOGICAL AND BIOCHEMICAL PARAMETERS IN GAROLE ...
VARIABILITY OF DISEASE RESISTANCE, HEMATOLOGICAL PARAMETERS ....unkown
47-53/Al-Seaf and Al-Harbi Research Article VARIABILITY OF DISEASE RESISTANCE, HEMATOLOGICAL PARAMETERS AND LYMPHOCYTE PROLIFERATION IN TWO GOAT BREEDS AND ...
olecular Genetic Variability, Within a Population of ....unkown
Molecular Genetic Variability, Within a Population ... non- race specific resistance Abstract The ...in the Eutypa lata population of single vineyard....
...in single cardiac myocytes reduces variability in parameters.unkown
Fitting membrane resistance in single cardiac myocytes reduces variability in parameters Jaspreet Kaur1, Anders Nygren1, Edward J. Vigmond2 1 University of ...
...in Single Cardiac Myocytes reduces Variability in Parameters.unkown
Fitting Membrane Resistance in Single Cardiac Myocytes reduces Variability in Parameters Jaspreet Kaur1, Anders Nygren1, Edward J Vigmond2 1 University of ...
...zonal vineyard management and phenolic variation in wine.unkown
vineyard management and phenolic variation in wine By Nathan Scarlett1 and ...According to Bramley (2005), "understanding and predicting the variability is...
...Structure in the Eutypa lata Population of a Single Vineyard.unkown
Genetic Structure in the Eutypa lata Population of a Single Vineyard J-P....Variability also was ob- served for cultural traits and radial growth rate ...
...variability of soil evaporation in a drip irrigated vineyard.unkown
The magnitude and spatial variability of soil evaporation in a drip irrigated...vineyard was found to be: 1) 0.47 of ETc from direct measurement of ...
...RS techniques for canopy variability evaluation in vineyards.unkown
variability evaluation in vineyards Niccolò Dainelli...(EC) within the Energy, Environment and ...vineyard management organisations with an integrated ...
...variation in correlations between vineyard canopy and wine....unkown
between vineyard canopy and winegrape composition and yield Andrew Hall; ...agriculture tool used to inform management of spatial variability in vineyards...
MANAGING VINEYARD VARIABILITY FOR A TARGETED WINE OUTCOME.unkown
MANAGING VINEYARD VARIABILITY FOR A TARGETED WINE OUTCOME FINAL REPORT to GRAPE AND WINE RESEARCH & DEVELOPMENT CORPORATION Project Number: CSU 03/05 ...
Spatial variability of potential pollutants in a vineyard of ....unkown
Thus, the objective of the present work was to study the concentrations of different elements and their variability in a vineyard soil of the Ribeiro D....
Spatial variability in Ontario Cabernet franc vineyards III. ....unkown
(3): 167-192, 2014 Journal Appl Spatial variability in Ontario Cabernet ...in this region to delineate vineyard sub-zones of differing quality levels....
...and Physical Variability in A Paso Robles Vineyard. Impact....unkown
Soil Chemical and Physical Variability in A Paso Robles Vineyard. Impact on Vine Root Distribution and Vine Vigor. Authors: Lambert, J.J.1, R.A. ...
...on soil moisture and runoff variability in vineyards under....unkown
variability in vineyards under different rainfall distributions in a ...variability of soil moisture at different depths in bare vineyard fields ...
Hydrological response variability in a small vineyard ....unkown
Hydrological response variability in a small vineyard catchment (D.O. Penedès, NE Spain): effects of rainfall intensity and soil moisture conditions THE ...
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