monitoring of co2 flux and contribution for components in ... · monitoring of co 2 flux and...

Monitoring of CO2 Flux and Contribution for Components in the Soil-Plant System in a Grassland from Northeastern Mexico

1 López-Santos Armando, 2 Cadena-Zapata Martín, 2 Zermeño-González Alejandro, 3 González-Cervantes Guillermo., 2 Gil-Marín José Alexander, 3 Sánchez-Cohen Ignacio

1 Unidad Regional Universitaria de Zonas Áridas de la UACh ([email protected]), 2 División de Ingeniería UAAAN, Buenavista, Saltillo, Coah. Méx., 3 Centro Nacional de Investigación Interdisciplinario en Relaciones Agua Suelo Planta Atmósfera del INIFAP, Gómez Palacio, Dgo, Mex.

Abstract The monitoring and quantification of CO2 released to the atmosphere by the rural production systems is an uprising need when facing the actual challenge of global warming. It is known, that in the last decade the change of land use and silviculture have contributed in a significant manner in the net emissions of CO2 to the atmosphere. However, is not quite clear the magnitude of the contribution of each individual ecosystem, and even it is least known the contribution of the separate action of the soil-plant system components. There are three methods for monitoring and quantifying the CO2 flux in an extensive open area condition: i) Open or close use of interchange gas chambers; ii) Using the technique of the Bowen Relation Method; and iii) Using the Eddy Covariance Method. In this experiment, the last mentioned was used for its high reliability in the measurements of mass and energy flux in extensive land conditions. The experiment was carried out at Rancho Los Angeles Municipality of Saltillo, Coahuila, México (25º 6.650’ N and 100º 59.413’ W). It was measured the CO2 flux, in plots of 2.4 ha after removing the native vegetation, dominated by three families (Chenopodacea, Euphorbacea y Asteraceae), using two tillage treatments: vertical tillage by chiseling (VT) and conventional tillage by disc ploughing (CT), the flux was measured as well in a reference plot without tillage treatment (NT). In all plots it was determined the magnitude of flux for each component at the soil-plant system. The results showed that under the predominant climatic conditions at Autumn 2006, when separating the components of the soil-plant system from the CO2 total flux monitored (FCO2tm), the more important contribution came from the soil in both tillage methods used (FCO2sLV=66 % and FCO2sLC=74 %). Key words: Eddy Covariance, Rural Production Systems, CO2 flux.

Introduction

Mexico ranks second among the Latin-Americans countries as CO2 emitter, with net emissions of 444.5 millions of metric tons for 1990, from this amount, it is estimated that the change in land use and silviculture contribute with 30.6 % (PNUMA-SEMARNAT, 2004). Considering the need to reduce release of CO2 and maintain the quality of the soil to support food production, the role and importance of the tillage practices and its impact in the organic matter should be reexamined (So et al, 2001; Lokupitiya et al, 2006), this is also important because of the raise of carbon bonus market among the countries that signed the Kyoto protocol (Inclán, 2007; Cervantes, 2007).

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López-Santos et al XIIIth World Water Congress, 2008 Montpellier, Fr.

The CO2 emissions from the surface on bare soil give a direct assessment in the short time about the carbon dynamic in the soil, but when vegetation is present, the interpretation of the total soil respiration is difficult due to the root contribution in the CO2 release (Rochete, 1999). It has been estimated that the rizosfera contributes with 40-50 % of the total soil respiration, and the 50-60 % remaining includes the decomposed microbial root exudates and other rhizodepotitions (Kuzyakov, 2002). Some authors (Rochete, 1999) have utilized values of isotopic carbon (13C) in order to measure CO2 separating from the total soil respiration that which comes from the rhizosphere in a maize crop (Zea mays L.) by using a portable chamber for gas exchange (LI-Cor), from those experiments, and they found that the rhizosphere contributes with 45% of the total respiration, this value agrees also with that reported by Kuzyakov (2002). Also they observed as well that the values of the soil respiration decreased from 3.3 to 1.4 g m-2d-1. Similarly, other authors (Qi et al, 2007) used a dark gas exchange fix chamber to measure total respiration, also the microbial and radicular from a grassland dominated by S. balcalensis and from bare soil, condition obtained by cutting the aerial part of the plants the day before the sampling, it was found that maximum spoil respiration occurred in July with a value of 6 g CO2 m-2d-1. In terrestrial ecosystems, the CO2 movements, as well as, other energy flux energetic, can be measured basically by three methods: 1) Eddy Covariance, (EC); 2) Bowen Relation, (BR); and 3) Open or Close, exchange gas chamber (CIG). Every method have advantages and disadvantages in relation to the measurements to characterize the flux behavior, because they are affected by variability in the local and surrounding conditions during day and night, such as humidity, temperature, barometric pressure, wind direction, etc. (Peters et al, 2001; Clark , 2001). In the present work, the total measure of CO2 flux, is part of an investigation based in the Eddy Covariance method, which have the follow characteristics: i) Direct measurements of the heat flux, water vapor and carbon dioxide; ii) Not assumption is made of coefficient values; iii) measurements are independent; iv) Allow to evaluate the precision of energy balance (Rn=H+LE+G); and v) Is considered the most precise method to measure superficial fluxes (Peters et al, 2001; Clark , 2001). Based on the above, the objectives of this work were: i) Monitoring CO2 flux in extensive outdoor conditions and ii) To asses the contribution of native vegetation in the CO2 sequestration by the separation of the soil-plant components system.

Materials and Methods

This investigation was carried out in the autumn 2006, at Rancho “Los Angeles”, municipality of Saltillo, Coah., México. This is a farm dedicated to the Charolais breed production, in a total surface around 6700 has. The site location is 25º 6.650’ N and

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100º 59.413 W, in the sub province called Gran Sierra Plegada, located at north of the Physiographic Region Sierra Madre Oriental, as could be seen in the Figure 1.

Figure 1. Field where was put the monitoring system (UTM coordinates system)

Two factors influence the cattle management in this place: One is the climate [BWhw(x´)(e)] which is semiarid (Garcia, 1975), having a precipitation of 350 mm per year, with a rainy season from May to September when falls 80 to 90 percent of total rain; the other factor is the landform; having to the north mountains like the Sierra Leona with a maxim altitude above sea level of 2850 m and to the south the Sierra Los Angeles with 2400 m above sea level, this condition have produced small valleys used as grazing lots, which have an average altitude of 2100 m. The soil type, is mainly Luvisol in a 40 % of total surface, the soils are deep with superficial horizons of dark color and high organic matter content (INEGI, 1976). The vegetation have a distribution in relation to the topographic, edaphic, and microclimatic characteristics in this place, in the hillslope prevail the shrub and in the hilltop prevail the pine trees (Pinus sp.) combined with shrubs; In the valleys is well established the grasses which are a compound that includes the following gramineae: Asistida, Buchloe, Boteloua, Mulenbergia, Steria e Stipia (Mellado, 2007), that are sharing spaces with other plants from families like Laminaceas, Chenopodaceas, Euphobaceas and Asteraceas.

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Selection, location and characteristics of the monitoring plot The monitoring of CO2 flux was made in an area of 35 has of the grazing lot number four located at the central part of the Ranch (rectangle at the Figure1 centre). Three plots of 2.4 ha each, with similar characteristics in soil type and vegetation were established. The dimensions of each plot were: a width of 120 m to N-S direction and a length of 200 m to E-W direction. The soil horizons from 0-0.30 and 0.30-0.60 m depth were studied, the resulting data showed texture with clay content greater than 40% (Boyoucos Hydrometer), PH with more than 8 (potentiometer), color in the soil surface layer (Munsell tables: 10YR 5/2), and total carbonates content grater than 37% (neutralization volume), from this data and based on the INEGI (2001) methodology, it is deduced that the soil characteristics match with a Feozem luvic (Hl) (INEGI 1976; FAO-ISRIC-ISSS-AISS-IBG, 1994). On the other hand, the native vegetation found in this season of the year and its relative importance value (RIV) was determined using line interception method and the more important species are shown in Table 1. Table 1. Floristic list and RIV in the monitoring plots Family Technical name RIV

Asteraceae Brickellia laciniata Gray 7

Asteraceae Zinnia acerosa (DC.) Gray 5

Asteraceae Aphanostephus ramosissimus DC. 5

Acanthaceae Dischoryste linearis (T.&G.)O. Ktze 7

Onagraceae Calylophus belandieri (Spach) Towner 10

Euphorbiaceae Euphorbia furcillata H.B.K. 2

Boraginaceae Tiquila canescens (DC.) Richardson 8

Laminacea Marrubium vulgare L. 50 It was noticed that in the grazing lot were experimental plots were established, the gramineae were not dominant spices due to this lot had been also used to establish winter forage crops like oats (Avena sativa) and barley (Hordeum vulgare L.), so other families as listed in table 1 were dominants. Monitoring duration of FCO2 and separation of components In the first plot the monitoring of FCO2 was made during space of 21 days (from October 20th to November 10th) under not disturbed soil-plant system, this condition was defined as total flux monitored or FCO2NT, in a second plot, the measurements of

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FCO2 was made during 18 days (from November 10th to November 28th) the condition of the plot was that the present vegetation was eliminated, with a chisel plough with delta wings at 25 cm depth. This condition of the system where vegetation were removed by vertical tillage was defined as FCO2SVT the flux was monitored directly from the tilled soil. In a third plot the native vegetation was removed using a disc plough, to a depth of 25 cm. The measurements of CO2 flux in this condition of bare soil defined as FCO2SCT was made for 27 days (until December 8th) Figure 2, illustrates the condition of the second and third plot where the two types of tillage were carried out.

Figure 2. Exclusion vegetal cover by VT (left) and CT (right)

Instrumentation for monitoring the systems The instruments used, were integrated in an automatic meteorological station (Eddy Station), which has the following components: (1) net radiometer Nr (model NR-LITE, Keep and Zonen Inc.) to measure the difference between short and long wave radiation, (2) a sensor to measure air temperature and water vapor, respectively (model HMP45C, Vaisala, Inc.) (3) two plates to measure heat flux soil (model HFT3, REBS Inc.), attached with two thermocouples of four tips (model TCAV, Campbell, Sci. Inc) for measuring the energetic gradient in the soil, G. The Eddy Station had other instruments like a sensor to measure wind speed and wind direction (model 03001-5, RM Young Inc.), an electronic pluviograph to measure the rain events (model TE525, Texas Instruments, Inc.). Also, were used two [datalogers] (models 23X and CR7, both of Campbell, Sci Inc.), and two solar panel one of 64 W and other of 20 W, which provided the energy required for the monitoring system.

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Results and Discussion

The results that will be discussed correspond to the first step of an investigation about the measure and evaluation of energy and mass flux under different conditions of soil management and season of the year. The purpose of this is to asses the role of the agroproductive systems from semiarid condition in the FCO2 dynamics. Figure 3, shows a flow chart for the analysis for the energy and mass flux from the data collected at the experimental plots.

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Figure 3. Diagram to analysis for the energy and mass flux

As a first step, the data of the experiment was arranged in two sets, the data from the eddy station was tabulated for analysis in excel files. Other data from laboratory, and field properties of soil and characteristics of the vegetation was arranged in another set for analysis. In a second step, the analysis of G and the wind direction (WD) was used as a criterion to correct every one of the flux variables. According to the experimental site prevailing wind direction, the acceptable range of WD were from 0 to 90o NE and from 270 to 360o NW. As a third step, energetic fluxes were determined, with the exception of Rn under soil surface and in soil surface with W m-2. The first is represented by the heat flux at the edaphic layer (G) at 0.08 m depth. The second is represented by the sensible heath (H) and latent heath or water vapor (LE) which were measured at 1.4 m above the soil surface.

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The correction of G was made using the formula:

[(Cds+θw•Cw) ρd •∆T•∆z] G = GD8 + ∆t (1)

Were GD8 is the heath flux, measured at 8 cm depth from the soil surface; Cds is caloric capacity of the minerals (840 J•Kg-1K-1); θw is the volumetric water content, Cw is the caloric capacity of the water (4190 J•Kg-1K-1); ∆T is the average change in temperature (oC) by the sensors placed from 2 to 6 cm depth. ∆z is the depth at which the plate for sensing the heath flux is placed (0.08m); and ∆t is the variation of time in seconds. For H and L, there were utilized the following equations (2) and (3):

H = ρa•Cp • w’ Ts’ -0.51•Ta [ ρa•Cp ] λE λ

(2)

LE = λw’ ρwv’ (3)

Were, ρa is the air density (kg m-3); Cp is the caloric capacity of the air (J kg-1 K-1); Ts is the sonic temperature measured whit the anemometer; Ta is the air temperature; w’ is the vertical win speed (m s-1); λ is the heat water vapor (J kg-1). w’Ts’, w’ρwv’ represents the covariance among the variables and the top bar means the average in a time interval that was established as 20 minutes. The frequency of data gathering for w’, Ts, and ρwv, and Ta were of 10 Hz. A fourth step was the correction of FCO2 according to the next formula (4).

FCO2 = ρCO2’• w’ (4)

Where ρCO2 is the density of carbon dioxide (μmol CO2 m-3) and ρwv is the density of the water vapor (kg m-3). The frequency on the measurements was the same as indicated before for the other variables. As a fifth step for the data from the accepted ranges of WD, the CR is determined according to the following equation:

[Rn-G] CR = [H + LE] (5)

In this case it is important to mention the instantaneous values measured with the carbon dioxide analyzer and the air water content from the 3D sonic anemometer.

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Those data are valid when corrected according to the local air density and correspond to values between 0.7 and 1 (Zermeño-Gonzalez, 2001; Ham, 2003). The sixth and last part of the process was to make the numerical and graphic analysis of FCO2 considering that as mass flux μmol m-2s-1 is independent from the calculations in equation (5). However, it is used as a reference, the data series that fall in the ranges that meet the criteria indicated for CR.

FCO2 measured above the soil-plant system In the first plot (reference plot) not disturbed by the tillage was made the total measuring of FCO2. In this phase of monitoring as can be seen in the Figure 4 for the day number 294, had a typical behavior represented for diurnal assimilation and nocturnal release. The first, due to the photosynthetic process from the phototropic organisms, with a rate maxim of assimilation close to 3 μmol de CO2 m-2s-1, which occurred around 13:00 hs; and the second like product from breakdown organic matter by macro and microorganism whit a maxim releaser of -3 μmol de CO2 m-2s-1, occurred between the 19:00 and the 20:00 hs. These results are similar to other reported (Scow, 1999; Pumpanen et al 2003; Qi et al, 2007). These allow to found the general characteristics in the FCO2 dynamic, for the release as well as assimilation, and whit this was estimated the proportion of the contribution from every component of the soil-plant system.

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Figure 4. CO2 flux from the soil with native vegetation (FCO2NT), observed at day 294

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FCO2 monitored whit native vegetation excluded by tillage The temporal elimination of the vegetation at the soil surface and the exposition of the root system to the action of environmental factors, allowed to have an exclusion of the vegetal cover and its root system, like can see in the Figure 5. From that, it was established that the flux measured under those soil management conditions correspond to the FCO2 produced or released under the soil condition left by both tillage system used VT and CT. This is FCO2SVT and FCO2SCT, respectively.

Figure 5. Exclusion vegetation effect. Aboveground (left) and root in the profile

view (right)

As a result of the use of both tillage method it could be observed a significant change in the FCO2 typical behavior, because it changed from capture source to release source; in both management systems the assimilation was negligible, and this situation was maintained for eight and nine continuing days. The release, although with a decrement trend on time was observed day and night in both cases, from 1.14 to 0.99 μmol CO2 m-2 s-1 and for 1.3 to 0.87 μmol CO2 m-2 s-1 for VT y CT, respectively. For VT, as it can be seen in the Figure 6, that a maximum value of 2 μmol CO2 m-2 s-1, occurred at the 14:00 h, it could be observed that the curve that represent the release, was maintained day and night being more pronounced for the last case, similar condition was present for CT as it can be seen en the Figure 7, also, in this tillage system can see a frequent variation in the releases of CO2 from the soil, the maximum value registered was almost same at 2 μmol CO2 m-2 s-1 and values of assimilation of less than 0.5 μmol CO2 m-2 s-1.

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Figure 6. CO2 flux from the soil without vegetation observed at day 316, two days after VT

The data gathered in the different treatments allow to separate and to quantify the participation of each component of the soil-plant studied, it also make the possibility to determine the impact of tillage in the flux dynamics of this production system.

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Figure 7. CO2 flux observed days from 333 to 335, between two and fourth days after CT

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FCO2 estimated for components fro the soil-plant system The net contribution for each component of the soil-plant system, to the release and assimilation of CO2 was estimated taking as a reference the average of four events of the instantaneous rates recorded by the sensor in the undisturbed plot, representing as FCO2mt. The difference resulting from the fluxes in the reference plot (undisturbed condition) and those rates measured in the plots disturbed for each type of tillage are the contribution of each condition to the CO2 released as it is presented in table 2. It should be also stated that under certain environmental condition some abiotic processes such as the dissolution of carbonates and chemical oxidation could be contributing also to the total CO2 flux (Hashimoto and Suzuki, 2002).

Table 2. Average of rate release of CO2 measured and estimated for components from the soil-plant system

LV LC

Events FCO2mt

(†)

FCO2 from the soil-plant system

(FCO2SPVT)‡

FCO2 from the

soil (FCO2sVT)

§

FCO2 from the soil-plant system

(FCO2SPCT)¶

FCO2 from the

soil (FCO2SCT)#

μmol CO2m-2s-1 1 1.600 0.200 1.400 0.730 0.870

2 1.270 0.295 0.975 0.020 1.250

3 1.710 1.030 0.680 0.170 1.540

4 1.618 0.628 0.990 0.741 0.877

Averages 1.527 0.508 1.011 0.415 1.134 Percents 100 34% 66% 26% 74%

† FCO2mt total instant rate measured in the NT plot. ‡ FCO2SPVT, estimated rate for difference among FCO2mt and FCO2sVT. § FCO2sVT, Instant rate measured in the plot with VT. ¶ FCO2SPCT, estimated rate for difference among FCO2tm and FCO2sCT # FCO2sCT, Instant rate measured in the plot with CT.

Conclusions

It was possible to establish the importance that vegetation has (where not gramineae are dominant) in the sequestration of carbon. The rhizosphere in the described soil condition for the experiment contributes with 26 to 34 % of the total flux of CO2.

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Both soil tillage methods used promotes the liberation of CO2 to the atmosphere, this is particularly important when land use have to be changed or when tillage is performed early in the season 4 or 6 months before the rainy season as it is the case in the region.

Recommendations

It should be further investigations on the natural soil capacity to return to the inicial condition after the tillage impact because this could be occur at different time scales for some morphologic and biologic properties. It is important to give a value to the roll played by grassland in the sequestration of carbon, given the importance that in the present and future will have the environmental services and the market of green bonus of carbon.

Thankfulness The work described here has been possible, thanks to the help giving from the UAAAN and CONACYT, particularly the Ingenieria Division, where are the follow Faculties: Ingenieria Mecanica Agrícola, Riego y Drenaje and Soils. Also, thanks for the staff of the Rancho “Los Anegels”, whos gave all kind of help.

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Montpellier, Fr.

Monitoring of CO2 Flux and Contribution for Components in the Soil-Plant System in a Grassland from Northeastern Mexico

1 López-Santos Armando, 2 Cadena-Zapata Martín, 2 Zermeño-González Alejandro, 3 González-Cervantes Guillermo., 2 Gil-Marín José Alexander, 3 Sánchez-Cohen Ignacio

1 Unidad Regional Universitaria de Zonas Áridas de la UACh ([email protected]), 2 División de Ingeniería UAAAN, Buenavista, Saltillo, Coah. Méx., 3 Centro Nacional de Investigación Interdisciplinario en Relaciones Agua Suelo Planta Atmósfera del INIFAP, Gómez Palacio, Dgo, Mex.

Abstract

The monitoring and quantification of CO2 released to the atmosphere by the rural production systems is an uprising need when facing the actual challenge of global warming. It is known, that in the last decade the change of land use and silviculture have contributed in a significant manner in the net emissions of CO2 to the atmosphere. However, is not quite clear the magnitude of the contribution of each individual ecosystem, and even it is least known the contribution of the separate action of the soil-plant system components. There are three methods for monitoring and quantifying the CO2 flux in an extensive open area condition: i) Open or close use of interchange gas chambers; ii) Using the technique of the Bowen Relation Method; and iii) Using the Eddy Covariance Method. In this experiment, the last mentioned was used for its high reliability in the measurements of mass and energy flux in extensive land conditions. The experiment was carried out at Rancho Los Angeles Municipality of Saltillo, Coahuila, México (25º 6.650’ N and 100º 59.413’ W). It was measured the CO2 flux, in plots of 2.4 ha after removing the native vegetation, dominated by three families (Chenopodacea, Euphorbacea y Asteraceae), using two tillage treatments: vertical tillage by chiseling (VT) and conventional tillage by disc ploughing (CT), the flux was measured as well in a reference plot without tillage treatment (NT). In all plots it was determined the magnitude of flux for each component at the soil-plant system. The results showed that under the predominant climatic conditions at Autumn 2006, when separating the components of the soil-plant system from the CO2 total flux monitored (FCO2tm), the more important contribution came from the soil in both tillage methods used (FCO2sLV=66 % and FCO2sLC=74 %).

Key words: Eddy Covariance, Rural Production Systems, CO2 flux.

Introduction

Mexico ranks second among the Latin-Americans countries as CO2 emitter, with net emissions of 444.5 millions of metric tons for 1990, from this amount, it is estimated that the change in land use and silviculture contribute with 30.6 % (PNUMA-SEMARNAT, 2004). Considering the need to reduce release of CO2 and maintain the quality of the soil to support food production, the role and importance of the tillage practices and its impact in the organic matter should be reexamined (So et al, 2001; Lokupitiya et al, 2006), this is also important because of the raise of carbon bonus market among the countries that signed the Kyoto protocol (Inclán, 2007; Cervantes, 2007).

The CO2 emissions from the surface on bare soil give a direct assessment in the short time about the carbon dynamic in the soil, but when vegetation is present, the interpretation of the total soil respiration is difficult due to the root contribution in the CO2 release (Rochete, 1999). It has been estimated that the rizosfera contributes with 40-50 % of the total soil respiration, and the 50-60 % remaining includes the decomposed microbial root exudates and other rhizodepotitions (Kuzyakov, 2002).

Some authors (Rochete, 1999) have utilized values of isotopic carbon (13C) in order to measure CO2 separating from the total soil respiration that which comes from the rhizosphere in a maize crop (Zea mays L.) by using a portable chamber for gas exchange (LI-Cor), from those experiments, and they found that the rhizosphere contributes with 45% of the total respiration, this value agrees also with that reported by Kuzyakov (2002). Also they observed as well that the values of the soil respiration decreased from 3.3 to 1.4 g m-2d-1.

Similarly, other authors (Qi et al, 2007) used a dark gas exchange fix chamber to measure total respiration, also the microbial and radicular from a grassland dominated by S. balcalensis and from bare soil, condition obtained by cutting the aerial part of the plants the day before the sampling, it was found that maximum spoil respiration occurred in July with a value of 6 g CO2 m-2d-1.

In terrestrial ecosystems, the CO2 movements, as well as, other energy flux energetic, can be measured basically by three methods: 1) Eddy Covariance, (EC); 2) Bowen Relation, (BR); and 3) Open or Close, exchange gas chamber (CIG). Every method have advantages and disadvantages in relation to the measurements to characterize the flux behavior, because they are affected by variability in the local and surrounding conditions during day and night, such as humidity, temperature, barometric pressure, wind direction, etc. (Peters et al, 2001; Clark , 2001).

In the present work, the total measure of CO2 flux, is part of an investigation based in the Eddy Covariance method, which have the follow characteristics: i) Direct measurements of the heat flux, water vapor and carbon dioxide; ii) Not assumption is made of coefficient values; iii) measurements are independent; iv) Allow to evaluate the precision of energy balance (Rn=H+LE+G); and v) Is considered the most precise method to measure superficial fluxes (Peters et al, 2001; Clark , 2001).

Based on the above, the objectives of this work were: i) Monitoring CO2 flux in extensive outdoor conditions and ii) To asses the contribution of native vegetation in the CO2 sequestration by the separation of the soil-plant components system.

Materials and Methods

This investigation was carried out in the autumn 2006, at Rancho “Los Angeles”, municipality of Saltillo, Coah., México. This is a farm dedicated to the Charolais breed production, in a total surface around 6700 has. The site location is 25º 6.650’ N and 100º 59.413 W, in the sub province called Gran Sierra Plegada, located at north of the Physiographic Region Sierra Madre Oriental, as could be seen in the Figure 1.

Figure 1. Field where was put the monitoring system (UTM coordinates system)

Two factors influence the cattle management in this place: One is the climate [BWhw(x´)(e)] which is semiarid (Garcia, 1975), having a precipitation of 350 mm per year, with a rainy season from May to September when falls 80 to 90 percent of total rain; the other factor is the landform; having to the north mountains like the Sierra Leona with a maxim altitude above sea level of 2850 m and to the south the Sierra Los Angeles with 2400 m above sea level, this condition have produced small valleys used as grazing lots, which have an average altitude of 2100 m. The soil type, is mainly Luvisol in a 40 % of total surface, the soils are deep with superficial horizons of dark color and high organic matter content (INEGI, 1976).

The vegetation have a distribution in relation to the topographic, edaphic, and microclimatic characteristics in this place, in the hillslope prevail the shrub and in the hilltop prevail the pine trees (Pinus sp.) combined with shrubs; In the valleys is well established the grasses which are a compound that includes the following gramineae: Asistida, Buchloe, Boteloua, Mulenbergia, Steria e Stipia (Mellado, 2007), that are sharing spaces with other plants from families like Laminaceas, Chenopodaceas, Euphobaceas and Asteraceas.

Selection, location and characteristics of the monitoring plot

The monitoring of CO2 flux was made in an area of 35 has of the grazing lot number four located at the central part of the Ranch (rectangle at the Figure1 centre). Three plots of 2.4 ha each, with similar characteristics in soil type and vegetation were established. The dimensions of each plot were: a width of 120 m to N-S direction and a length of 200 m to E-W direction.

The soil horizons from 0-0.30 and 0.30-0.60 m depth were studied, the resulting data showed texture with clay content greater than 40% (Boyoucos Hydrometer), PH with more than 8 (potentiometer), color in the soil surface layer (Munsell tables: 10YR 5/2), and total carbonates content grater than 37% (neutralization volume), from this data and based on the INEGI (2001) methodology, it is deduced that the soil characteristics match with a Feozem luvic (Hl) (INEGI 1976; FAO-ISRIC-ISSS-AISS-IBG, 1994).

On the other hand, the native vegetation found in this season of the year and its relative importance value (RIV) was determined using line interception method and the more important species are shown in Table 1.

Table 1. Floristic list and RIV in the monitoring plots

Family

Technical name

RIV

Asteraceae

Brickellia laciniata Gray

7

Asteraceae

Zinnia acerosa (DC.) Gray

5

Asteraceae

Aphanostephus ramosissimus DC.

5

Acanthaceae

Dischoryste linearis (T.&G.)O. Ktze

7

Onagraceae

Calylophus belandieri (Spach) Towner

10

Euphorbiaceae

Euphorbia furcillata H.B.K.

2

Boraginaceae

Tiquila canescens (DC.) Richardson

8

Laminacea

Marrubium vulgare L.

50

It was noticed that in the grazing lot were experimental plots were established, the gramineae were not dominant spices due to this lot had been also used to establish winter forage crops like oats (Avena sativa) and barley (Hordeum vulgare L.), so other families as listed in table 1 were dominants.

Monitoring duration of FCO2 and separation of components

In the first plot the monitoring of FCO2 was made during space of 21 days (from October 20th to November 10th) under not disturbed soil-plant system, this condition was defined as total flux monitored or FCO2NT, in a second plot, the measurements of FCO2 was made during 18 days (from November 10th to November 28th) the condition of the plot was that the present vegetation was eliminated, with a chisel plough with delta wings at 25 cm depth. This condition of the system where vegetation were removed by vertical tillage was defined as FCO2SVT the flux was monitored directly from the tilled soil. In a third plot the native vegetation was removed using a disc plough, to a depth of 25 cm. The measurements of CO2 flux in this condition of bare soil defined as FCO2SCT was made for 27 days (until December 8th) Figure 2, illustrates the condition of the second and third plot where the two types of tillage were carried out.

Figure 2. Exclusion vegetal cover by VT (left) and CT (right)

Instrumentation for monitoring the systems

The instruments used, were integrated in an automatic meteorological station (Eddy Station), which has the following components: (1) net radiometer Nr (model NR-LITE, Keep and Zonen Inc.) to measure the difference between short and long wave radiation, (2) a sensor to measure air temperature and water vapor, respectively (model HMP45C, Vaisala, Inc.) (3) two plates to measure heat flux soil (model HFT3, REBS Inc.), attached with two thermocouples of four tips (model TCAV, Campbell, Sci. Inc) for measuring the energetic gradient in the soil, G. The Eddy Station had other instruments like a sensor to measure wind speed and wind direction (model 03001-5, RM Young Inc.), an electronic pluviograph to measure the rain events (model TE525, Texas Instruments, Inc.). Also, were used two [datalogers] (models 23X and CR7, both of Campbell, Sci Inc.), and two solar panel one of 64 W and other of 20 W, which provided the energy required for the monitoring system.

Results and Discussion

The results that will be discussed correspond to the first step of an investigation about the measure and evaluation of energy and mass flux under different conditions of soil management and season of the year. The purpose of this is to asses the role of the agroproductive systems from semiarid condition in the FCO2 dynamics. Figure 3, shows a flow chart for the analysis for the energy and mass flux from the data collected at the experimental plots.

Start

Reviewing and

organization

of

electronic

files

wy Da

assessing

Resumes

Analysisway

to

G y WD

WD

analysis

H y LE

correction

(airdensity)

CR

evaluation

Ouput

acceptable

Series

to

flux variables

Numeric

analysis

and

graphics

to

FCO2

RnandG

correction

FCO2

correction

(airdensity)

Start

Reviewing and

organization

of

electronic

files

wy Da

assessing

Resumes

Analysisway

to

G y WD

WD

analysis

H y LE

correction

(airdensity)

CR

evaluation

Ouput

acceptable

Series

to

flux variables

Numeric

analysis

and

graphics

to

FCO2

RnandG

correction

FCO2

correction

(airdensity)

Figure 3. Diagram to analysis for the energy and mass flux

As a first step, the data of the experiment was arranged in two sets, the data from the eddy station was tabulated for analysis in excel files. Other data from laboratory, and field properties of soil and characteristics of the vegetation was arranged in another set for analysis.

In a second step, the analysis of G and the wind direction (WD) was used as a criterion to correct every one of the flux variables. According to the experimental site prevailing wind direction, the acceptable range of WD were from 0 to 90o NE and from 270 to 360o NW.

As a third step, energetic fluxes were determined, with the exception of Rn under soil surface and in soil surface with W m-2. The first is represented by the heat flux at the edaphic layer (G) at 0.08 m depth. The second is represented by the sensible heath (H) and latent heath or water vapor (LE) which were measured at 1.4 m above the soil surface.

The correction of G was made using the formula:

G =

GD8 +

[(Cds+(w•Cw) (d •∆T•∆z]

(1)

∆t

Were GD8 is the heath flux, measured at 8 cm depth from the soil surface; Cds is caloric capacity of the minerals (840 J•Kg-1K-1); (w is the volumetric water content, Cw is the caloric capacity of the water (4190 J•Kg-1K-1); ∆T is the average change in temperature (oC) by the sensors placed from 2 to 6 cm depth. ∆z is the depth at which the plate for sensing the heath flux is placed (0.08m); and ∆t is the variation of time in seconds.

For H and L, there were utilized the following equations (2) and (3):

-1.000

-0.500

0.000

0.500

1.000

1.500

2.000

2.500

08:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00

Hora del día

FCO

2

(µmol CO

2

m

-2

s

-1

)

Día 316

Houroftheday

CO

2

releasing

(Day)

CO

2

releasing

(Nigth)

-1.000

-0.500

0.000

0.500

1.000

1.500

2.000

2.500

08:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00

Hora del día

FCO

2

(µmol CO

2

m

-2

s

-1

)

Día 316

Houroftheday

CO

2

releasing

(Day)

CO

2

releasing

(Nigth)

H = ρa•Cp • w’ Ts’ -0.51•Ta [ ρa•Cp ] λE

λ

(2)

LE = λw’ ρwv’

(3)

Were, (a is the air density (kg m-3); Cp is the caloric capacity of the air (J kg-1 K-1); Ts is the sonic temperature measured whit the anemometer; Ta is the air temperature; w’ is the vertical win speed (m s-1); ( is the heat water vapor (J kg-1). w’Ts’, w’(wv’ represents the covariance among the variables and the top bar means the average in a time interval that was established as 20 minutes. The frequency of data gathering for w’, Ts, and (wv, and Ta were of 10 Hz.

A fourth step was the correction of FCO2 according to the next formula (4).

FCO2 = ρCO2’• w’

(4)

Where (CO2 is the density of carbon dioxide ((mol CO2 m-3) and (wv is the density of the water vapor (kg m-3). The frequency on the measurements was the same as indicated before for the other variables.

As a fifth step for the data from the accepted ranges of WD, the CR is determined according to the following equation:

CR =

[Rn-G]

(5)

[H + LE]

In this case it is important to mention the instantaneous values measured with the carbon dioxide analyzer and the air water content from the 3D sonic anemometer. Those data are valid when corrected according to the local air density and correspond to values between 0.7 and 1 (Zermeño-Gonzalez, 2001; Ham, 2003).

The sixth and last part of the process was to make the numerical and graphic analysis of FCO2 considering that as mass flux (mol m-2s-1 is independent from the calculations in equation (5). However, it is used as a reference, the data series that fall in the ranges that meet the criteria indicated for CR.

FCO2 measured above the soil-plant system

In the first plot (reference plot) not disturbed by the tillage was made the total measuring of FCO2. In this phase of monitoring as can be seen in the Figure 4 for the day number 294, had a typical behavior represented for diurnal assimilation and nocturnal release. The first, due to the photosynthetic process from the phototropic organisms, with a rate maxim of assimilation close to 3 (mol de CO2 m-2s-1, which occurred around 13:00 hs; and the second like product from breakdown organic matter by macro and microorganism whit a maxim releaser of -3 (mol de CO2 m-2s-1, occurred between the 19:00 and the 20:00 hs. These results are similar to other reported (Scow, 1999; Pumpanen et al 2003; Qi et al, 2007).

These allow to found the general characteristics in the FCO2 dynamic, for the release as well as assimilation, and whit this was estimated the proportion of the contribution from every component of the soil-plant system.

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

10:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:00

Hour fo the day

FCO

2

(µmolCO

2

m

-2

s

-1

)

Figure 4. CO2 flux from the soil with native vegetation (FCO2NT), observed at day 294

FCO2 monitored whit native vegetation excluded by tillage

The temporal elimination of the vegetation at the soil surface and the exposition of the root system to the action of environmental factors, allowed to have an exclusion of the vegetal cover and its root system, like can see in the Figure 5. From that, it was established that the flux measured under those soil management conditions correspond to the FCO2 produced or released under the soil condition left by both tillage system used VT and CT. This is FCO2SVT and FCO2SCT, respectively.

Figure 5. Exclusion vegetation effect. Aboveground (left) and root in the profile view (right)

As a result of the use of both tillage method it could be observed a significant change in the FCO2 typical behavior, because it changed from capture source to release source; in both management systems the assimilation was negligible, and this situation was maintained for eight and nine continuing days. The release, although with a decrement trend on time was observed day and night in both cases, from 1.14 to 0.99 (mol CO2 m-2 s-1 and for 1.3 to 0.87 (mol CO2 m-2 s-1 for VT y CT, respectively.

For VT, as it can be seen in the Figure 6, that a maximum value of 2 (mol CO2 m-2 s-1, occurred at the 14:00 h, it could be observed that the curve that represent the release, was maintained day and night being more pronounced for the last case, similar condition was present for CT as it can be seen en the Figure 7, also, in this tillage system can see a frequent variation in the releases of CO2 from the soil, the maximum value registered was almost same at 2 (mol CO2 m-2 s-1 and values of assimilation of less than 0.5 (mol CO2 m-2 s-1.

Figure 6. CO2 flux from the soil without vegetation observed at day 316, two days after VT

The data gathered in the different treatments allow to separate and to quantify the participation of each component of the soil-plant studied, it also make the possibility to determine the impact of tillage in the flux dynamics of this production system.

EMBED Excel.Chart.8 \s

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

11/29/06 18:0011/29/06 20:0011/29/06 22:00

11/30/06 0:0011/30/06 2:0011/30/06 4:0011/30/06 6:0011/30/06 8:00

11/30/06 10:0011/30/06 12:0011/30/06 14:0011/30/06 16:0011/30/06 18:0011/30/06 20:0011/30/06 22:00

12/1/06 0:0012/1/06 2:0012/1/06 4:0012/1/06 6:00

Time, day and hour

FCO

2

(µmol CO

2

m

-2

s

-1

)

Figure 7. CO2 flux observed days from 333 to 335, between two and fourth days after CT

FCO2 estimated for components fro the soil-plant system

The net contribution for each component of the soil-plant system, to the release and assimilation of CO2 was estimated taking as a reference the average of four events of the instantaneous rates recorded by the sensor in the undisturbed plot, representing as FCO2mt. The difference resulting from the fluxes in the reference plot (undisturbed condition) and those rates measured in the plots disturbed for each type of tillage are the contribution of each condition to the CO2 released as it is presented in table 2.

It should be also stated that under certain environmental condition some abiotic processes such as the dissolution of carbonates and chemical oxidation could be contributing also to the total CO2 flux (Hashimoto and Suzuki, 2002).

Table 2. Average of rate release of CO2 measured and estimated for components from the soil-plant system

Events

FCO2mt

(†)

LV

LC

FCO2

from the soil-plant system (FCO2SPVT)‡

FCO2 from the

soil (FCO2sVT) §

FCO2

from the soil-plant system (FCO2SPCT)¶

FCO2

from the soil (FCO2SCT)#

(mol CO2m-2s-1

1

1.600

0.200

1.400

0.730

0.870

2

1.270

0.295

0.975

0.020

1.250

3

1.710

1.030

0.680

0.170

1.540

4

1.618

0.628

0.990

0.741

0.877

Averages

1.527

0.508

1.011

0.415

1.134

Percents

100

34%

66%

26%

74%

† FCO2mt total instant rate measured in the NT plot.

‡ FCO2SPVT, estimated rate for difference among FCO2mt and FCO2sVT.

§ FCO2sVT, Instant rate measured in the plot with VT.

¶ FCO2SPCT, estimated rate for difference among FCO2tm and FCO2sCT

# FCO2sCT, Instant rate measured in the plot with CT.

Conclusions

It was possible to establish the importance that vegetation has (where not gramineae are dominant) in the sequestration of carbon. The rhizosphere in the described soil condition for the experiment contributes with 26 to 34 % of the total flux of CO2.

Both soil tillage methods used promotes the liberation of CO2 to the atmosphere, this is particularly important when land use have to be changed or when tillage is performed early in the season 4 or 6 months before the rainy season as it is the case in the region.

Recommendations

It should be further investigations on the natural soil capacity to return to the inicial condition after the tillage impact because this could be occur at different time scales for some morphologic and biologic properties. It is important to give a value to the roll played by grassland in the sequestration of carbon, given the importance that in the present and future will have the environmental services and the market of green bonus of carbon.

Thankfulness

The work described here has been possible, thanks to the help giving from the UAAAN and CONACYT, particularly the Ingenieria Division, where are the follow Faculties: Ingenieria Mecanica Agrícola, Riego y Drenaje and Soils. Also, thanks for the staff of the Rancho “Los Anegels”, whos gave all kind of help.

Cited references

Cervantes, 2007. El mecanismo de desarrollo limpio y las reducciones certificadas de emisiones. Dirección de Proyectos de Cambio Climático en la Secretaría de Medio Ambiente y Recursos Naturales, SEMARNAT

Clark DA, Brown S, Kiclighter WD, Chambers QJ, Thomlinson RJ, Ni J. 2001. Measuring Net Primary Production in Forest: Concepts and Field Methods. Ecological Society of America. Ecological Applications 11(2): 356-370

FAO-ISRIC-ISSS-AISS-IBG, 1994. World Reference Base for Soil Resources. Wagening, Rome. P 56.

García E. 1975. Climas Coahuila y Nuevo León, precipitación y probabilidad de lluvia en la República Mexicana y su evolución. CETENAL, México, D.F.

Ham JM, Heilman JL. Experimental Test of Density and Energy-Balance Corrections on Carbon Dioxide Flux as Measured Using Open-Path Eddy covariance. American Society of Agronomy, 2003; 95: 1393 – 1403.

Hashimoto S, Suzuki M. 2002. Vertical Distribution of Carbon Dioxide Diffusion Coefficients and Production Rates in Forest Soil. Soil Sci. Soc. Am. J. 66: 1151-1158

Inclán GU. 2007. Mercado de Bonos de Carbono y sus beneficios potenciales para proyectos en México. Dirección de Cambio Climático-SENER. Consulted (07/19/07), in http://www.conae.gob.mx/work/sites/CONAE/resources/LocalContent/2962/1/images/22_sener.pdf.

INEGI. Thematic Cartography of: Edaphology, Geology, Topography, Vegetation and Land Use. Maps: Agua Nueva (G14-C43) y Huachichil (G14-C44). Escale 1:50,000. 1976

Kuzyakov Y. 2002. Separating Microbial Respiration of Exudates from Root Respiration in non-sterile soils: a comparison of four Methods. Soil Biology & Biochemistry, 34: 1621-1631

Lokupitiya E, Paustian K, 2006. Agricultural Soil Gas Emissions: A Review of National Inventory Methods. J. Environ. Qual. 35: 1413-1427

Mellado M. 2007. Traslape de Dietas entre el Perrito de la Pradera (Cynomys mexicanus) y Bovinos en un Pastizal. Mediano Abierto. Consulated (08/19/08) in http://www.uaaan.mx/DirInv/Rdos2003/Zaridas/dietas.pdf s/f.

Peters G, Fischer B, Munser H. 2001. Eddy Covariance Measurements with Closed-Path Optical Humidity Sensors: A feasible Concepts? Journal of Atmospheric and Oceanic Technology, American Meteorological Society..

PNUMA-SEMARNAT, 2004. El Cambio Climático en América Latina y El Caribe (Preliminar Version). Consultated (07/07/07) in http://www.pnuma.org/Cambioclimatico/CAMBIO%20CLIMATICO-web.pdf

Pumpanen J, Ilvesniemi H, Hari P. 2003. A process Based Model Predicting Soil Carbon Dioxide Efflux and Concentrations. Soil Sci. Soc. Am. J. 67: 402-413

Qi YCh, Dong Y, Liu J, Domroes M, Geng Y, Liu L, et al. 2007. Effect of the Conversion of Grassland to Spring Wheat Field on the CO2 Emission Characteristics in Inner Mongolia, China. Soil and Tillage Research. 94: 310-320

Rochete P, Flanagan LB, Grgorich EG. 1999. Separating Soil Respiration into Plant and Soil Components Using Analyses of the natural Abundance of Carbón-13. Soil Sci. Soc. Am. J. 63: 1207-1213

Scow MK. 1999. Soil Microbial Communities and Carbon Flow in Agroecosistems. Ed. Academic Press, Editado por Jakson, L. E. Carolina University, USA. Pp 367-413.

So HB, Dalal RC, Chan KY, Menzies NM, Freebarm DM. 2001. Potential of conservation tillage to reduce carbon dioxide emission in Australian soils. In D.E Sttot, RH Mothar and GC Steinhardt (eds). Sustaining the global farm. Selected papers from the 10Th International Soil Conservation Organization meeting.

Zermeño-González A. 2001. Métodos Micrometeorológicos para medir flujos de calor y vapor de agua entre los cultivos y la atmósfera. XIII Semana Internacional de Agronomía, 2001

CO2 releasing

(Night)

CO2 assimilation

(Day)

CO2 releasing-assimilation

(Day and Night)

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_1235738914.xls

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FCO2 ()

Linea

Hour fo the day

FCO2 (µmolCO2 m-2s-1)

-2.2991438417

0

-2.1891799098

0

-1.9524208319

0

-2.0792159779

0

-2.0175015263

0

-2.0522860354

0

-2.239673552

0

-2.0870705444

0

-2.5796640762

0

-1.4003570105

0

-1.8850959756

0

-1.8402127381

0

-1.9793507744

0

-2.0186236072

0

-1.9468104272

0

-1.4340194386

0

-1.624773198

0

-1.607941984

0

-1.5967211746

0

-1.4923676474

0

-1.8705089234

0

-1.3016138879

0

-1.2544864885

0

-0.1582134122

0

0.2782760726

0

0.8819556172

0

1.8839738947

0

2.8276439634

0

2.6803708403

0

2.5330977172

0

2.2385514711

0

1.5523989775

0

1.2093227308

0

0.866246484

0

1.0377846074

0

1.1521433563

0

DIA 294

DiaHoras del diaFCO2ValorTiempoSum_RnSum_LESum_FCO2LE/RnFCO2/Rnasimilación

µmolCO2/m2sLineaa corregirSegmento(MJ/m2)(MJ/m2)(mmolCO2/m2)promedio

29410:20-2.2990-1.859

29410:40-2.1890-3.184Asimilación10:20 a 18:0011.4754.022-50.0140.351-4.359

29411:00-1.9520Liberacion

29411:20-2.0790Liberación18:20 a 22:00-0.46922.112-47.135promedio

29411:40-2.01801.715

29412:00-2.0520-0.382mm H2O

29412:20-2.2400-3.296L=2.421.662

29412:40-2.0870

29413:00-2.5800

29413:20-1.4000

29413:40-1.8850

29414:00-1.8400

29414:20-1.9790

29414:40-2.0190

29415:00-1.9470

29415:20-1.4340

29415:40-1.6250

29416:00-1.6080

29416:20-1.5970

29416:40-1.4920

29417:00-1.8710

29417:20-1.3020

29417:40-1.2540

29418:00-0.1580

29418:200.2780

29418:400.8820

29419:001.8840

29419:202.8280

29419:402.6800

29420:002.53300.213

29420:202.2390

29420:401.55205.857

29421:001.20900.353

29421:200.8660

29421:401.0380-3.178

29422:001.15204.417

Integrar: Rn, LE, FCO2 de las 10:20 a las 18:00

DiaHoras del diaLERnIntegrar: FCO2 de las 18:20 a las 22:00

W/m2W/m2

29410:20109270

29410:40136330

29411:00144370

29411:20140380

29411:40141410

29412:00136438

29412:20145490

29412:40186545

29413:00177545

29413:20171554

29413:40194572

29414:00199567

29414:20199560

29414:40191538

29415:00182516

29415:20172485

29415:40148444

29416:00131405

29416:20128366

29416:40106308

29417:0099257

29417:2079191

29417:4073142

29418:004031

DiaHoras del diaRn

W/m2

29418:20-1

29418:40-10

29419:00-30

29419:20-32

29419:40-37

29420:00-33

29420:20-36

29420:40-44

29421:00-43

29421:20-52

29421:40-51

29422:00-47

DIA 294

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

FCO2 ()

Linea

Hora del dia

FCO2 (µmolCO2/m-2s-1)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

DIA 295 Y 296

DiaHoras del diaFCO2ValorTiempoSum_RnSum_LESum_FCO2LE/RnFCO2/Rnasimilación

µmolCO2/m2sLineaa corregirSegmento(MJ/m2)(MJ/m2)(mmolCO2/m2)promedio

10/22/06 9:00295900-0.5570-1.562

10/22/06 9:20295920-0.40600.145Asimilación09:00 a 14:404.2181.597-31.6230.379-7.497

10/22/06 9:40295940-0.38300.196Liberacion

10/22/06 10:002951000-0.2780Liberación22:00 a 03:40-0.79226.620-33.601promedio

10/22/06 10:202951020-0.31501.273

10/22/06 10:402951040-0.4850mm H2O

10/22/06 11:002951100-1.0360L=2.420.660

10/22/06 11:202951120-2.0850

10/22/06 11:402951140-2.6410

10/22/06 12:002951200-2.5210

10/22/06 12:202951220-1.8750

10/22/06 12:402951240-1.6170

10/22/06 13:002951300-2.2320

10/22/06 13:202951320-1.7770

10/22/06 13:402951340-1.5240

10/22/06 14:002951400-2.8550

10/22/06 14:202951420-2.5530

10/22/06 14:402951440-2.9820

10/22/06 15:0029515000

10/22/06 15:2029515200

10/22/06 15:4029515400

10/22/06 16:0029516000

10/22/06 16:2029516200

10/22/06 16:4029516400

10/22/06 17:0029517000

10/22/06 17:2029517200

10/22/06 17:4029517400

10/22/06 18:0029518000

10/22/06 18:2029518200

10/22/06 18:4029518400

10/22/06 19:0029519000

10/22/06 19:2029519200

10/22/06 19:4029519400

10/22/06 20:0029520000

10/22/06 20:2029520200

10/22/06 20:4029520400

10/22/06 21:0029521000

10/22/06 21:2029521200

10/22/06 21:4029521400

10/22/06 22:0029522000.1140-1.128

10/22/06 22:2029522200.6470

10/22/06 22:4029522400.4170

10/22/06 23:0029523001.4930

10/22/06 23:2029523201.67802.015Integrar: de las 9:00 a las 14:40 Rn, LE, FCO2

10/22/06 23:4029523401.8620Integrar: FCO2 de las 22:00 a las 3:40

10/23/06 0:0029601.68602.630

10/23/06 0:20296201.51003.953

10/23/06 0:40296401.1580

10/23/06 1:002961001.3450

10/23/06 1:202961201.7870

10/23/06 1:402961402.2760

10/23/06 2:002962002.0000

10/23/06 2:202962201.0810

10/23/06 2:402962401.4070

10/23/06 3:002963000.6180

10/23/06 3:202963200.4790

10/23/06 3:402963401.3640

DiaHoras del diaLERn

W/m2W/m2

2959:001531

2959:201531

2959:401428

29510:001230

29510:202145

29510:404281

29511:004495

29511:2049117

29511:4068168

29512:0068169

29512:2067178

29512:40156372

29513:00124380

29513:20161458

29513:40139440

29514:00112307

29514:20157389

29514:40152421

DiaHoras del diaRn

W/m2

2952200-48

2952220-39

2952240-47

2952300-50

2952320-60

2952340-61

2960-60

29620-55

29640-59

296100-46

296120-45

296140-38

296200-42

296220-10

296240-7

296300-7

296320-8

296340-8

Día 294

Rn

LE

Hora del dia

Flujos (W/m2)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Día 294

DIA 295 Y 296

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

Del día 295 al 296

FCO2

Linea

Fecha y hora del dia


0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

DIA 296 Y 297

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

Día 295

Rn

LE

Hora del dia

Flujos (W/m2)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

DIA 297 Y 298

DiaHoras del diaFCO2Valor aTiempoSum_RnSum_LESum_FCO2LE/RnFCO2/Rn

µmolCO2/m2sLineacorregirSegmento(MJ/m2)(MJ/m2)(mmolCO2/m2)

10/23/06 9:002969001.0310

10/23/06 9:202969200.1990Asimilación09:40 a 18:004.2512.080-61.4870.489-14.465

10/23/06 9:40296940-0.2380

10/23/06 10:002961000-0.8090Asimilación09:40 a 14:002.5791.071-32.9250.415-12.766

10/23/06 10:202961020-2.2030-0.109

10/23/06 10:402961040-3.3160Liberación18:20 a 9:00-1.00977.708-77.021

10/23/06 11:002961100-2.4850

10/23/06 11:202961120-3.3770mm H2O

10/23/06 11:402961140-3.0220L=1.421.465

10/23/06 12:002961200-3.1510L=2.420.443

10/23/06 12:202961220-2.8900

10/23/06 12:402961240-2.6940

10/23/06 13:002961300-3.4590

10/23/06 13:202961320-2.5800

10/23/06 13:402961340-3.1860

10/23/06 14:002961400-2.3460

10/23/06 14:202961420-2.5560-0.748

10/23/06 14:402961440-2.7660-5.498

10/23/06 15:002961500-1.96000.721

10/23/06 15:202961520-1.57904.484

10/23/06 15:402961540-1.1990-6.724

10/23/06 16:002961600-1.1530

10/23/06 16:202961620-1.2440

10/23/06 16:402961640-1.0510

10/23/06 17:002961700-0.3840

10/23/06 17:202961720-1.2870

10/23/06 17:402961740-0.4520

10/23/06 18:0029618000.0620

10/23/06 18:2029618200.3460

10/23/06 18:4029618401.1180

10/23/06 19:0029619001.5010

10/23/06 19:2029619201.3810

10/23/06 19:4029619401.6030

10/23/06 20:0029620001.97008.082

10/23/06 20:2029620202.2640-0.313

10/23/06 20:4029620402.9250

10/23/06 21:0029621003.33501.292

10/23/06 21:2029621203.7440

10/23/06 21:4029621402.2870

10/23/06 22:0029622002.45204.886

10/23/06 22:2029622201.5910-0.018

10/23/06 22:4029622401.3240

10/23/06 23:0029623001.16200.618

10/23/06 23:2029623200.7910

10/23/06 23:4029623401.0010

10/24/06 0:0029701.3840

10/24/06 0:20297201.2050

10/24/06 0:40297401.2740

10/24/06 1:002971001.2890

10/24/06 1:202971201.2070

10/24/06 1:402971400.9480

10/24/06 2:002972000.9920

10/24/06 2:202972200.7440

10/24/06 2:402972401.0170

10/24/06 3:002973001.5090Integrar: Rn, LE y FCO2 de las 9:40 a las 18:00 hrs

10/24/06 3:202973201.35300.310Integrar: FCO2 de las 18:20 a las 9:00 hrs

10/24/06 3:402973401.1960

10/24/06 4:002974001.1050Integrar: Rn, LE y FCO2 de las 9:40 a las 14:00 hrs

10/24/06 4:202974201.35800.187

10/24/06 4:402974401.6110

10/24/06 5:002975001.72900.675

10/24/06 5:202975201.8460

10/24/06 5:402975401.3950

10/24/06 6:002976001.1160-0.056

10/24/06 6:202976200.8380

10/24/06 6:402976401.2050

10/24/06 7:002977000.8880

10/24/06 7:202977201.1160

10/24/06 7:402977401.23500.536

10/24/06 8:002978001.3530

10/24/06 8:202978201.8620

10/24/06 8:402978401.1120

10/24/06 9:002979000.4920-1.349

10/24/06 9:202979200.1820-19.585

10/24/06 9:40297940-0.1280

10/24/06 10:002971000-0.62000.204

10/24/06 10:202971020-1.66001.246

10/24/06 10:402971040-2.7010

10/24/06 11:002971100-1.9130

10/24/06 11:202971120-1.9150

10/24/06 11:402971140-2.5090

10/24/06 12:002971200-2.9840

10/24/06 12:202971220-2.3530

10/24/06 12:402971240-1.7130

10/24/06 13:002971300-1.8790

10/24/06 13:202971320-2.7560

10/24/06 13:402971340-2.5110

10/24/06 14:002971400-3.7170


W/m2W/m2

2969:00139

2969:201626

2969:403051

29610:003054

29610:202959

29610:4036100

29611:0044120

29611:2077212

29611:4098287

29612:0079239

29612:2090262

29612:4051171

29613:0088251

29613:2065192

29613:4080211

29614:0073190

29614:2070150

29614:40103140

29615:0099130

29615:2077110

29615:4070100

29616:00105136

29616:2075110

29616:4074109

29617:005059

29617:208484

29617:405337

29618:003212

DiaHoras del diaLERnLinea

W/m2W/m2

2979:00-2-50

2979:20120

2979:4015220

29710:0017330

29710:2010330

29710:4025800

29711:00501220

29711:20611450

29711:40932000

29712:001022250

29712:20841870

29712:40662020

29713:00832120

29713:201002500

29713:401052840

29714:001793300


W/m2W/m2

296182026

29618401

2961900-13

2961920-18

2961940-22

2962000-42

2962020-36

2962040-33

2962100-32

2962120-34

2962140-31

2962200-35

2962220-34

2962240-29

2962300-29

2962320-28

2962340-18

2970-20

29720-18

29740-29

297100-11

297120-9

297140-22

297200-27

297220-21

297240-7

297300-7

297320-8

297340-7

297400-9

297420-7

297440-7

297500-8

297520-21

297540-18

297600-20

297620-23

297640-23

297700-24

297720-21

297740-18

297800-12

297820-11

297840-9

297900-5

DIA 297 Y 298

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

Día 296

Rn

LE

Hora del dia

Flujos (W/m2)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

FCO2

Linea

Fecha y hora del dia


0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

DiaHoras del diaFCO2Valor aTiempoSum_RnSum_LESum_FCO2LE/RnFCO2/Rn

µmolCO2/m2sLineacorregirSegmento(MJ/m2)(MJ/m2)(mmolCO2/m2)

10/24/06 21:0029721001.4980

10/24/06 21:2029721202.2610Asimilación09:00 a 14:404.4721.472-52.5980.329-11.762

10/24/06 21:4029721402.45201.056

10/24/06 22:0029722002.6430Liberación21:00 a 8:40-1.30672.221-55.284

10/24/06 22:2029722202.52901.380

10/24/06 22:4029722402.34701.370mm H2O

10/24/06 23:0029723002.4160L=2.420.608

10/24/06 23:2029723202.27800.977

10/24/06 23:4029723402.12500.805Integrar: FCO2 de las 21:00 a las 8:40

10/25/06 0:0029802.1400Integrar: Rn, LE, FCO2 de las 9:00 a las 14:40

10/25/06 0:20298201.82000.992

10/25/06 0:40298401.5000

10/25/06 1:002981001.81303.465

10/25/06 1:202981202.0350

10/25/06 1:402981401.9030

10/25/06 2:002982001.4860

10/25/06 2:202982201.7180

10/25/06 2:402982402.1730

10/25/06 3:002983001.94900.239

10/25/06 3:202983201.8570

10/25/06 3:402983401.8170

10/25/06 4:002984001.8840

10/25/06 4:202984201.6180

10/25/06 4:402984401.53800.246

10/25/06 5:002985001.4590

10/25/06 5:202985201.22500.621

10/25/06 5:402985400.9920

10/25/06 6:002986001.225011.609

10/25/06 6:202986201.045010.553

10/25/06 6:402986401.09105.885

10/25/06 7:002987001.0990

10/25/06 7:202987201.1300

10/25/06 7:402987401.4090

10/25/06 8:002988000.9000

10/25/06 8:202988200.9950

10/25/06 8:402988401.1250

10/25/06 9:002989000.0770

10/25/06 9:20298920-1.2370

10/25/06 9:40298940-1.3790

10/25/06 10:002981000-1.8810

10/25/06 10:202981020-2.5020

10/25/06 10:402981040-3.1010

10/25/06 11:002981100-3.1800

10/25/06 11:202981120-3.4670

10/25/06 11:402981140-3.6570

10/25/06 12:002981200-3.6250

10/25/06 12:202981220-2.9200

10/25/06 12:402981240-3.0080Integrar: FCO2 de las 21:00 a las 8:40

10/25/06 13:002981300-3.0330Integrar: Rn, LE, FCO2 de las 9:00 a las 14:40

10/25/06 13:202981320-1.9240

10/25/06 13:402981340-2.1490

10/25/06 14:002981400-2.4320

10/25/06 14:202981420-3.0830

10/25/06 14:402981440-2.5830


W/m2W/m2

2989:001832

2989:203875

2989:404191

29810:004197

29810:2059142

29810:4078205

29811:0074230

29811:2079255

29811:4084276

29812:0098299

29812:2077250

29812:4083312

29813:00132390

29813:2056211

29813:4069220

29814:0075247

29814:2082260

29814:40101300

DiaHoras del diaRn

W/m2

2972100-31

2972120-31

2972140-35

2972200-58

2972220-61

2972240-57

2972300-57

2972320-49

2972340-41

2980-35

29820-35

29840-58

298100-46

298120-35

298140-26

298200-27

298220-27

298240-32

298300-21

298320-12

298340-12

298400-19

298420-32

298440-38

298500-34

298520-33

298540-32

298600-35

298620-36

298640-30

298700-30

298720-19

298740-6

2988005

29882010

29884022

Del día 296 al 297

Rn

LE

Linea C

Horas del dia

Flujos (W/m2)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Día 297

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

00

FCO2

Linea

Hora del dia

FCO2 (µmolCO2 m-2s-1)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Del día 297 al 298

Rn

LE

Hora del dia

Flujos (W/m2)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Día 298

_1267379234.xls

Gráfico2

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39050.777777777839050.7777777778

39050.791666666739050.7916666667

39050.805555555639050.8055555556

39050.819444444439050.8194444444

39050.833333333339050.8333333333

39050.847222222239050.8472222222

39050.861111111139050.8611111111

39050.87539050.875

39050.888888888939050.8888888889

39050.902777777839050.9027777778

39050.916666666739050.9166666667

39050.930555555639050.9305555556

39050.944444444439050.9444444444

39050.958333333339050.9583333333

39050.972222222239050.9722222222

39050.986111111139050.9861111111

3905139051

39051.013888888939051.0138888889

39051.027777777839051.0277777778

39051.041666666739051.0416666667

39051.055555555639051.0555555556

39051.069444444439051.0694444444

39051.083333333339051.0833333333

39051.097222222239051.0972222222

39051.111111111139051.1111111111

39051.12539051.125

39051.138888888939051.1388888889

39051.152777777839051.1527777778

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39051.180555555639051.1805555556

39051.194444444439051.1944444444

39051.208333333339051.2083333333

39051.222222222239051.2222222222

39051.236111111139051.2361111111

39051.2539051.25

39051.263888888939051.2638888889

39051.277777777839051.2777777778

39051.291666666739051.2916666667

39051.305555555639051.3055555556

39051.319444444439051.3194444444

39051.333333333339051.3333333333

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39051.37539051.375

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39051.402777777839051.4027777778

39051.416666666739051.4166666667

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39051.444444444439051.4444444444

39051.458333333339051.4583333333

39051.472222222239051.4722222222

39051.486111111139051.4861111111

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39051.513888888939051.5138888889

39051.527777777839051.5277777778

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39051.569444444439051.5694444444

39051.583333333339051.5833333333

39051.597222222239051.5972222222

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39051.62539051.625

39051.638888888939051.6388888889

39051.652777777839051.6527777778

39051.666

monitoring of co2 flux and contribution for components in ... · monitoring of co 2 flux and...

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