CO2 Gas Exchange Research Articles

Investigating the Effects of Random Balloon Pulsation on Gas Exchange in a Respiratory Assist Catheter

We are developing an intravenous respiratory assist catheter, which uses hollow-fiber membranes wrapped around a pulsating balloon that increases oxygenation and CO2 removal with increased balloon pulsation. Our current pulsation system operates with a constant rate of pulsation and delivered balloon volume. This study examined the hypothesis that random balloon pulsation would disrupt fluid entrainment within the fiber bundle and increase our overall gas exchange. We implemented two different modes for random (rates and delivered volume) versus constant pulsation. The impact on gas exchange was measured in a 3 l/min water flow loop at 37 degrees C. CO2 gas exchange for randomized beat rate mode was comparable to its corresponding average constant pulsation (e.g., constant 286 beats/min versus randomized 200-400 beats/min was 299.5+/-0.9 and 302.2+/-1.4 ml/min/m, respectively). Random volume mode CO2 exchange was also comparable to constant delivered balloon volume (100% inflation and deflation) (e.g., 294.3+/-0.6 and 301.1+/-1.7 ml/min/m, random 50-100% inflation and constant, respectively). Greater active mixing was seen with constant pulsation as compared with randomly changing the parameters of balloon pulsation.

Air-sea CO2 flux and gas exchange coefficient at the Sesoko coral reefs, Okinawa, Japan

The partial pressure of CO2 in seawater and air-sea CO2 flux were measured at the Sesoko coral reefs in Okinawa, Japan, and the effect of various perturbations on the gas exchange coefficient is discussed. The CO2 flux varied from -1.0 to 1.3mmol m-2h-1, which corresponded with the variation in partial pressure of CO2 in seawater. Atmospheric CO2 was absorbed by seawater during the day and released at night. This was mainly because of community photosynthesis and respiration. The gas exchange coefficient obtained from the chamber method was relatively larger than the wind dependent gas exchange coefficient. In the present study, the gas exchange coefficient was 5 and 30 times higher than that reported by Wanninkhof (1992) and Liss and Merlivat (1986), respectively when the wind velocity was set to 2.8m s-1. Our result (13.8±2.7cm h-1) was close to that reported by Komori and Shimada (1995), which took into account both the effects of turbulence and wind velocity on the gas exchange coefficient, indicating that not only wind, but also the effects of turbulence and other factors are important in the coefficient estimation at the Sesoko coral reefs.

Untersuchungen zur CO2-Gas-Austauschrate bei transgenen Fructan bildenden Kartoffellinien ( Solanum tuberosum L.) unter Einsatz eines modularen Großküvettensystems: (Investigations to the CO2 gas exchange rate in transgenic fructans generating potato lines ( Solanum tuberosum L.) by implementation of a modular cuvette system)

This survey was aimed at comparing the CO2 gas exchange rate of transgenic potato lines and of the isogenic line Désirée in order to establish if genetic modification has resulted in ecologically relevant changes. In examining two transgenic potato lines and one isogenic line, a modular whole-plant cuvette system was implemented for the first time. Furthermore, suitability of such a cuvette system for comparative examination was to be tested in the survey at hand. The lowest CO2 exchange rate was observed in the SST/FFT line. The SST line achieved the highest CO2 exchange rate of all genotypes tested. Measurement of CO2 exchange rate, and additionally collected data on morphologic and characteristics of yield physiology, resulted in distinctly correlating data. The phenotypical changes observed could be classified within the growth and yield profile specified by the German Federal Office of Plant Varieties (Bundessortenamt) for potato varieties permitted for cultivation in Germany. A changed growth rate of crop in the transgenic lines could not be established. A modular whole-plant cuvette system can be implemented in comparative gas exchange measurements in a partly air-conditioned cell.

Isidia ontogeny and its effect on the CO2 gas exchanges of the epiphytic lichen Pseudevernia furfuracea (L.) Zopf

The development of isidia in thalli of Pseudevernia furfuracea from the Carnic Alps (North-eastern Italy), and the effects of these structures on CO2 gas exchanges were investigated. The ontogenetic events were studied by comparison of sections stained with different histochemical tests and SEM observations. A high cell turnover rate in both symbiotic partners is the first sign of isidium development, followed by an increased aplanosporogenesis of algae and growth of neighbouring medullary hyphae which become oriented upwards. Large nuclei and an intense cytoplasm activity characterize the mycobiont cells. The surface of very young isidia shows an irregular structure of spherical to ovoid protruding tips of perpendicular cortical hyphae, that are later organised in a pseudomeristematic area similar to that observed in the apex of growing lobes. CO2 gas exchange measurements carried out in the laboratory confirmed the high metabolic activity of isidia. At optimal water content and favourable light conditions, isolated isidia had rates of gross photosynthesis and dark respiration that were twice those of non-isidiate lobes. Isolated isidia also had a very low CO2 saturation point, probably because of their favourable surface/volume ratio, and a high light saturation, probably linked to their high content of photosynthetic pigments. The different roles played by isidia in the biology of Pseudevernia furfuracea, and particularly their rejuvenating effect on aged lobes, are discussed, and the presence of thalloconidia is briefly mentioned.

Genotypic variation in drought response of silver birch (Betula pendula Roth): leaf and root morphology and carbon partitioning

Young trees of four clones of Betula pendula from origins with different amounts of precipitation were subjected to prolonged drought periods in two subsequent summers. The aims of this study were: (1) to investigate the drought response of silver birch in a multi-level approach and to elucidate the basis of the particularly wide physiological amplitude of this species and (2) to analyse variation in drought responses of different genotypes in order to identify potential genotypic differences with regard to their adaptability to drought. Responses of different physiological, biochemical, and morphological parameters to water shortage were regularly analysed: CO2 and H2O gas exchange were investigated under ambient and elevated CO2 concentration; leaf water status and osmotic adjustment were analysed with the pressure-chamber technique and pressure volume curves; leaves were analysed for chlorophyll and nitrogen content, and carbon isotopic composition; at the end of each drought period, trees were completely harvested and above- and belowground masses and areas determined.The following results were obtained: (1) Reduction of stomatal conductance was the first and most plastic response of silver birch to water shortage, thus effectively maintaining predawn leaf water potentials; non-stomatal limitations of photosynthesis were not detected. (2) Silver birch appeared to be capable of osmotic adjustment, which was mainly used during the phase of establishment. (3) Marked responses of total leaf area and the especially plastic phenology of this species have to be classified as adaptations to drought. (4) Both within-organ and between-organ allocation of biomass responded to drought. (5) Genotypes from drier locations displayed higher degrees of osmotic adjustment than those from origins with better water supply. (6) Genotypes from drier locations reached higher stomatal conductances under both well watered and drought stressed conditions. (7) Paticularly one genotype from a stand prone to summer drought displayed a more prodigal water use strategy than the genotypes from origins with higher precipitation. This strategy in combination with effective mechanisms of both drought avoidance and tolerance is classified as highly competitive and adapted to habitats with edaphic summer droughts.In conclusion, all genotypes responded to water shortage by marked mechanisms of drought avoidance on all levels of plant performance; The extent of response, however, appeared to be partly affected by adaptations to places of origin, with the genotypes from drier locations displaying a tendency for more prodigal water use strategies.

Foliar trichomes, boundary layers, and gas exchange in 12 species of epiphytic Tillandsia (Bromeliaceae)

We examined the relationships between H2O and CO2 gas exchange parameters and leaf trichome cover in 12 species of Tillandsia that exhibit a wide range in trichome size and trichome cover. Previous investigations have hypothesized that trichomes function to enhance boundary layers around Tillandsioid leaves thereby buffering the evaporative demand of the atmosphere and retarding transpirational water loss. Data presented herein suggest that trichome-enhanced boundary layers have negligible effects on Tillandsia gas exchange, as indicated by the lack of statistically significant relationships in regression analyses of gas exchange parameters and trichome cover. We calculated trichome and leaf boundary layer components, and their associated effects on H2O and CO2 gas exchange. The results further indicate trichome-enhanced boundary layers do not significantly reduce transpirational water loss. We conclude that although the trichomes undoubtedly increase the thickness of the boundary layer, the increase due to Tillandsioid trichomes is inconsequential in terms of whole leaf boundary layers, and any associated reduction in transpirational water loss is also negligible within the whole plant gas exchange pathway.

Chamber series and space-scale analysis of CO<sub>2</sub> gas-exchange in grassland vegetation: A novel approach

Significant part of our work was developing a new type of CO2 and H2O gas exchange chambers fit for measuring stand patches. Ground areas of six chambers (ranged between 0.044–4.531 m2) constituted a logarithmic series with doubling diameters from 7.5 to 240.0 cm. We demonstrate one of the first results for stand net ecosystem CO2 exchange (NEE) rates and temporal variability for two characteristic Central European grassland types: loess and sand. The measured mean NEE rates and their ranges in these grasslands were similar to values reported in other studies on temperate grasslands. We also dealt with the spatial scale dependence from ecophysiological point of view. Our chamber-series measurement was performed in a perennial ruderal weed association. The variability of CO2-assimilation of this weed vegetation showed clear spatial scale-dependence. We found the lowest variability of the vegetation photosynthesis at the small-middle scales. The results of spatial variability suggest the 0.2832 m2 patch size is the characteristic unit of the investigated weed association and there is a kind of synphysiological minimi-area with characteristic size for each vegetation type.

Photosynthetic light-use by three bromeliads originating from shaded sites (Ananas ananassoides, Ananas comosus cv. Panare) and exposed sites (Pitcairnia pruinosa) in the medium Orinoco basin, Venezuela

Three Bromeliaceae species of the medium Orinoco basin, Venezuela, were compared in their light-use characteristics. The bromeliads studied were two species of pineapple, i.e. the wild species Ananas ananassoides originating from the floor of covered moist forest, and the primitive cultivar Panare of Ananas comosus mostly cultivated in semi-shaded palm swamps, and Pitcairnia pruinosa, a species abundant in highly sun exposed sites on rock outcrops. Ananas species are Crassulacean acid metabolism (CAM) plants, P. pruinosa is C3 plant. Plants were grown at low daily irradiance (LL = 1.3 mol m−2 d−1 corresponding to an incident irradiance of 30 μmol m−2 s−1) and at high irradiance (HL = 14.7 mol m−2 d−1 or 340 μmol m−2 s−1), and CO2 and H2O-vapour gas exchange and photochemical (qP) and non-photochemical quenching (qNP) of chlorophyll a fluorescence of photosystem 2 (PS2) were measured after transfer to LL, medium irradiance (ML = 4.1 mol m−2 d−1 or 95 μmol m−2 s−1) and HL. All plants showed flexible light-use, and qP was kept high under all conditions. LL-grown plants of Ananas showed particularly high rates of CAM-photosynthesis when transferred to HL and were not photoinhibited.

Correlation between stand photosynthesis and composition at micro-scale in loess grassland

Introduction Compositional and functional patterns and trends in micro-scale, that of the organization of grassland communities, are more difficult to explain than phenomena of the population or macro ecological level (Lawton 1999). To observe rules and forces, mechanisms that govern them, selection of appropriate scales is necessary (Bartha 2000, Elmore 1980). Small-scale spatial heterogeneity of CO2 gas exchange in grasslands partly depends on plant community compositional traits. Species richness, species composition, horizontal and vertical structure and green leaf area index (LAI) of grasslands are diverse in space, and affect net ecosystem CO2 exchange through its components (gross photosynthesis, soil respiration etc.). Study of the rapport of diversity and productivity has long history. LAI and NDVI, considered here with reference to compositional richness (Csillag et al. 2001, Kertesz et al. 2001) are usually related to photosynthetic performance. Papers published on the relationships of the CO2 exchange and diversity (Craine et al. 2001, Spehn et al. 2000, Stocker et al. 1999) report that diverse ecosystems perform better both aboveand below-ground, than monocultures, other articles on the topic of photosynthesis and species dominance or cover (LeCain et al. 2002, McAllister et al. 1998) emphasize that dominant species with high cover are more effective in their gas exchange, than rare species, but these studies mainly refer to leaf level photosynthesis and CO2 enrichment experiences. We investigated the effect of species richness and surface cover on photosynthesis at the same spatial scale: stand-level gross photosynthesis and composition of the measured stand patches have been compared to: (i) find the relationships between photosynthesis and vegetation cover, (ii) reveal the rapport between species number and photosynthesis and the importance of the dominant species.

Physiological Reactions of Plants at CO2 Emitting Mofettes and Thermal Effect of Emerging Gas-Probable Use for Remote Sensing

Plants growing within mofette fields (CO2 emitting gas vents) show specific adaptations according to their extreme habitat. The closer they grow to the gas emitting vents and the higher the concentration of the escaping CO2 gas, the smaller the actual height and the total biomass of the plants. For some species a concomitant decrease in total chlorophyll was found. Additionally, photosynthesis as measured using CO2 gas-exchange and fluorescence clearly followed the same rule, being higher at the margins of the area and lower close to the vents. As fluorescence can be detected via remote sensors, chlorophyll fluorescence may be used to detect physiological changes from remote. In addition an abiotic thermal parameter may help in recognising mofettes in the field. As the flux of escaping CO2 gas from the soil may influence the soil temperature at and around the vent openings the application of infrared thermovision systems may be used additionally help to confirm their existence or detect unknown ones.The emerging gas dampens the temperature fluctuations of the soil imposed by the weather: it will cool the soil, when the gas is cooler than the undisturbed surface and it will warm the soil when the gas is warmer. Subtraction of multi-temporal IR images and setting temperature difference thresholds in difference images allows to disclose this effect and thus to detect the vents as well as their spatial extension.

Sugar Beet Photosynthesis under Conditions of Increasing Water Deficiency in Soil and Protective Effects of a Low-Molecular-Weight Alcohol

The rate of CO2 gas exchange, transpiration, stomatal conductivity, and efficiency of the use of water were assessed in leaves of the sugar beet (Beta vulgaris var. Saccharifera (Alef) Krass.) sprayed with 40% methanol, against the background of increasing water deficiency in soil. A decrease in the negative impact of water deficiency in experimental plants was shown to be due to the larger stress-resistance of the photosynthetic apparatus, higher rate of photosynthesis, and more effective use of water.

Growth and maintenance respiration for individual plants in hierarchically structured canopies of Medicago sativa and Helianthus annuus: the contribution of current and old assimilates.

• Respiratory costs of Medicago sativa and Helianthus annuus individuals growing in hierarchically structured stands in a controlled environment were analysed with regard to the daily rate of carbon (C) assimilation. • Net assimilation of new C (An , g C d-1 ) and respiration rates of new (Rnew , g C d-1 ) and old C (Rold , g C d-1 ) were assessed by 13 CO2 labelling and gas exchange measurements. • Specific respiration rate of old C (rold , g C g-1 C d-1 ) decreased exponentially with increasing shoot biomass, but was not affected by the instantaneous relative growth rate (Δwi ). The growth coefficient g (Rnew : An ) was c.0.32. In the most severely shaded subordinate plants, g was <0.2, but low g stimulated rold . The contribution of Rnew to total respiraton (fR, new ) and the carbon use efficiency CUE (1-R/(An +Rnew )) were c.0.68 and 0.62 for Δwi >0.1, respectively. For Δwi <0.1, fR, new and CUE decreased with decreasing Δwi in both dominant and subordinate plants. • The results suggest that Rold was closely related to maintenance, whereas Rnew was primarily involved in growth.

CO2 and Lung Mechanical or Gas Exchange Function: The authors reply

CO2 and Lung Mechanical or Gas Exchange Function: The authors reply

Growth in relation to microclimatic conditions and physiological characteristics of four Lobaria pulmonaria populations in two contrasting habitats

The aim of the present study was to compare the physiological characteristics of various populations of the lichen Lobaria pulmonaria in Portugal and Sweden. For this, indirect markers of algal (photobiont) and fungal (mycobiont) activity were measured, as well as their CO2 gasexchange characteristics. Microclimatic conditions and the lichens growth performance in the two countries were compared using reciprocal transplantation. Two populations of L. pulmonaria represented each country: one collected from forest interior conditions and one from forest edge habitats. A non‐transplanted “wild” population was also studied in each country, in order to evaluate any transplantation effects per se. The main hypothesis were that; 1) growth should be faster in Portugal due to higher light availability; 2) the energy use efficiency of lichen biomass gain should be similar for the native populations in their respective native habitat; 3) if the lichens were able to adapt to the environmental conditions in the foreign habitat this should be revealed as similar growth rates among all thalli transplanted at the same site, regardless of their origin. Physiologically, the Portuguese and Swedish populations were very similar, both concerning their CO2 gas exchange characteristics and distribution of resources between photo‐ and mycobiont tissue. Environmental conditions were more advantageous for L. pulmonaria growth in Portugal, i.e. higher photon flux densities and ambient temperatures when the lichens were wet and active, and a lower fraction of the active time occurring in darkness. However, despite similar physiological characteristics of all the studied populations, the Swedish lichens were not able to grow as well in Portugal as the native, while all populations had similarly low growth rates in Sweden.

A geochemical perspective and assessment of leakage potential for a mature carbon dioxide–enhanced oil recovery project and as a prototype for carbon dioxide sequestration; Rangely field, Colorado

Measurements of CO2 and CH4 soil gas concentrations and gas exchange with the atmosphere at a large-scale CO2-enhanced oil recovery (EOR) operation at Rangely, Colorado, United States allowed assessment of the microseepage potential. Shallow and deep soil gas concentrations and direct transport of CO2 and CH4, complemented by carbon isotopes, have demonstrated an estimated microseepage rate to the atmosphere of approximately 400 t CH4/yr from the 78-km2 area of the Rangely field. Preliminary estimates of deep-sourced CO2 losses are in the range of 170 to less than 3800 t/yr. Several holes as much as 9 m deep for nested sampling of gas composition, stable carbon isotopic ratios for CO2 and CH4, and carbon-14 measurements on CO2 indicate that deep-sourced CO2 microseepage loss was detected. Methanotrophic oxidation of microseeping CH4 to CO2 in soils demonstrates significant contribution to soil gas CO2 in high CH4 flux areas, necessitating a revision of the estimated direct CO2 microseepage rate to less than 170 t/yr over the Rangely field.An evaluation of produced water quality from pre-CO2-EOR to 1999 demonstrates an increase in some parameters, particularly of Ca2+ and HCO3, indicating dissolution of ferroan calcite and ferroan dolomite in the Weber Formation. Inverse computer modeling suggested carbonate mineral sequestration was possible within the constraints of evolution of produced water quality. X-ray analyses of well scales, however, do not support the presence of significant mineral sequestration. Instead, modeling indicates that the bulk of the CO2 that has been injected since 1986 is sequestered as dissolved CO2.

Influence of elevated CO2 and nitrogen nutrition on photosynthesis and nitrate photo‐assimilation in maize (Zea mays L.)

ABSTRACTMeasurements of CO2 and O2 gas exchange and chlorophyll a fluorescence were used to test the hypothesis that elevated atmospheric CO2 inhibits nitrate (NO3–) photo‐assimilation in the C4 plant, maize (Zea mays L.). The assimilatory quotient (AQ), the ratio of net CO2 assimilation to net O2 evolution, decreases as NO3– photo‐assimilation increases so that the difference in AQ between the ammonium‐ and nitrate‐fed plants (ΔAQ) provided an in planta estimate of NO3– photo‐assimilation. In fully expanded maize leaves, NO3– photo‐assimilation was detectable only under high light and was not affected by CO2 treatments. Furthermore, CO2 assimilation and O2 evolution were higher under NO3– than ammonia (NH4+) regardless of CO2 levels. In conclusion, NO3– photo‐assimilation in maize primarily occurred at high light when reducing equivalents were presumably not limiting. Nitrate photo‐assimilation enhanced C4 photosynthesis, and in contrast to C3 plants, elevated CO2 did not inhibit foliar NO3– photo‐assimilation.

Chlorophyll fluorescence and photosynthetic response to light in 1-year-old needles during spring and early summer in Pinus leucodermis

Ten-year-old trees from four Italian populations of Pinus leucodermis (populations A, B, C and D), which were collected from different sites at different altitudes, were grown near Florence, Italy. Needle CO2 gas exchange and chlorophyll fluorescence response to increasing light intensities were evaluated; gas exchange and chlorophyll fluorescence variation between April and July were also monitored. Populations A, B and C showed a similar photosynthetic response to increasing photosynthetic photon flux density (PPFD) intensities, while at various light intensities population D, which originated from the highest altitude, showed the highest photosynthetic rates. In this population photosynthesis was saturated at PPFDs higher than 900 µmol m–2s–1 and a slow decrease of effective photosystem II quantum yield and F′V/F′M in response to increasing PPFDs were found. The same trees also showed a faster recovery in photosynthesis from limitations induced by winter temperatures than the other three populations. This work showed that photosynthetic response to light in population D was different from the other populations; trees from this population were probably naturally selected to prevent photoinhibition due to excess light.

Dark chilling effects on soybean genotypes during vegetative development: parallel studies of CO2 assimilation, chlorophyll a fluorescence kinetics O-J-I-P and nitrogen fixation.

The effects of dark chilling on CO2 assimilation, chlorophyll a fluorescence kinetics and nitrogen fixation were compared in two Glycine max (L.) Merr. genotypes. The aim was to elucidate the mechanisms by which photosynthesis was inhibited as well as identification of selection criteria for dark chilling tolerance. Seedlings were dark chilled (8 degrees C) for 9 consecutive nights but kept at normal day temperatures (28 degrees C). CO2 gas exchange analysis indicated that photosynthesis in Maple Arrow was inhibited largely as a result of stomatal limitation, while in Fiskeby V, it indicated inhibition of the mesophyll reactions. Increased intercellular CO2 concentration and decreased carboxylation efficiency suggested loss of Rubisco activity in Fiskeby V, although no effect on the KM (CO2) of Rubisco was observed. Quantification and deconvolution of the Chl a fluorescence transients into several phenomenological and biophysical parameters (JIP-test) revealed large genotypic differences in the response of PSII to dark chilling. These parameters differentially changed in the two genotypes during the progression of the chilling treatment. Among them, the performance index, reflecting several responses of the photochemical apparatus, provided the best preliminary overall assessment of the genotypes. In contrast, the quantum yield of primary photochemistry varphiPo (FV/FM) was quite insensitive. The recovery of most of the JIP-test parameters in Maple Arrow after 6 and 9 nights of dark chilling was a major genotypic difference. Genotypic differences were also observed with regard to the ureide response and N2 fixation appeared to be more sensitive to dark chilling than CO2 assimilation. The JIP-test provided information consistent with results derived from CO2 assimilation and N2 fixation studies suggesting that it can substitute the much more time-consuming methods for the detection of chilling stress and can well satisfy the requirements of a rapid and accurate screening method.

Induction of CO2-gas exchange and electron transport: comparison of dynamic and steady-state responses in Fagus sylvatica leaves

Photosynthetic induction was followed in a juvenile understorey beech (Fagus sylvatica L.) in a shaded habitat which was temporarily exposed to direct sunlight passing through a gap in the canopy. Simultaneous in situ measurements of leaf gas exchange and chlorophyll fluorescence were carried out and a steady-state light response curve of photosynthesis was recorded. The measured dynamic carbon gain was compared to the predicted carbon gain, calculated from the steady-state light response curve and the ambient photon flux density (PPFD) incident during the sunfleck event. Integration over the first 20 min, during which induction took place, resulted in a deviation of 27% if any induction effects are disregarded. The carbon gain was overestimated by 11% when the carbon gain was integrated over the whole measuring period of about 1 h including a 40-min period of full induction. In situ gas exchange measurements under constant saturating light, following dark adaptation, revealed an induction error of 21%. About 20 min was required to reach the final steady-state level of photosynthesis. The data show that the prediction of the carbon gain by steady-state models leads to a distinct overestimation of the CO2 uptake, irrespective of whether the induction state rises concurrently with the incident radiation or saturating light induces photosynthesis. From chlorophyll fluorescence and absorptance data, rates of linear electron transport (ETR) were calculated. Uninduced leaves exposed to saturating light of constant PPFD show an initial fast down-regulation of ETR, due to excessive light, and a subsequent increase in electron transport attributable to the increasing energy demand during induction of carbon fixation. No difference in the ETR to PPFD relationship between data sets sampled during induction and in the fully induced state was found when both the incident light and the induction state of carbon fixation increased concomitantly. The proportion of electrons fed into alternative pathways besides carbon fixation was higher during induction as compared to the fully induced state. Thus, electrons were used for carbon fixation with a higher efficiency when full induction was reached.

Parameterization of the CO2 and H2O gas exchange of several temperate deciduous broad‐leaved trees at the leaf scale considering seasonal changes

ABSTRACTA combined model to simulate CO2 and H2O gas exchange at the leaf scale was parameterized using data obtained from in situ leaf‐scale observations of diurnal and seasonal changes in the CO2 and H2O gas exchange of four temperate deciduous broad‐leaved trees using a porometric method. The model consists of a Ball et al. type stomatal conductance submodel [Ball, Woodrow &amp; Berry, pp. 221–224 in Progress in Photosynthesis Research (ed. I. Biggins), Martinus‐Nijhoff Publishers, Dordrecht, The Netherlands, 1987] and a Farquhar et al. type biochemical submodel of photosynthesis (Farquhar, von Caemmerer &amp; Berry, Planta 149, 78–90, 1980). In these submodels, several parameters were optimized for each tree species as representative of the quantitative characteristics related to gas exchange. The results show that the seasonal physiological changes of Vcmax25 in the biochemical model of photosynthesis should be used to estimate the long‐term CO2 gas exchange. For Rd25 in the biochemical model of photosynthesis and m in the Ball et al. type stomatal conductance model, the difference should be counted during the leaf expansion period.