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1.
It has been shown that 4% carbon dioxide (CO 2) in the air above reaction mixture inhibits the initiation of the formation of silver nanoparticles from complexes with biogenic
amines (noradrenaline and serotonin). At the same concentration of CO 2 in the air above solution of AgNO 3, which is used for staining nerve tissues by the method of Golgi, neurons are preferentially stained, whereas at a concentration
of 0.06%, vessels are stained. It is suggested that the entry of free silver ions to neurons is due to the inhibition of sites
of initiation of silver nanoparticles in vessels at high CO 2 concentrations, while the lack of inhibition leads to silver precipitation in vessels at low CO 2 concentrations. It can be assumed that, for stable silver impregnation, the concentration of CO 2 must be controlled. 相似文献
2.
A leaf disk assay for photorespiration has been developed based on the rate of release of recently fixed 14CO 2 in light in a rapid stream of CO 2-free air at 30° to 35°. In tobacco leaves (Havana Seed) photorespiration with this assay is 3 to 5 times greater than the 14CO 2 output in the dark. In maize, photorespiration is only 2% of that in tobacco. The importance of open leaf stomata, rapid flow rates of CO2-free air, elevated temperatures, and oxygen in the atmosphere in order to obtain release into the air of a larger portion of the 14CO2 evolved within the tissue in the light was established in tobacco. Photorespiration, but not dark respiration, was inhibited by α-hydroxy-2-pyridinemethanesulfonic acid, an inhibitor of glycolate oxidase, and by 3-(4-chlorophenyl)-1,1-dimethylurea (CMU), an inhibitor of photosynthetic electron transport, under conditions which did not affect the stomata. These experiments show that the substrates of photorespiration and dark respiration differ and also provide additional support for the role of glycolate as a major substrate of photorespiration. It was also shown that at 35° the quantity of 14CO2 released in the assay may represent only 33% of the gross 14CO2 evolved in the light, the remainder being recycled within the tissue. It was concluded that maize does not evolve appreciable quantities of CO2 in the light and that this largely accounts for the greater efficiency of net photosynthesis exhibited by maize. Hence low rates of photorespiration may be expected to be correlated with a high rate of CO2 uptake at the normal concentrations of CO2 found in air and at higher light intensities. 相似文献
3.
Elevated atmospheric CO 2 has been shown to rapidly alter plant physiology and ecosystem productivity, but contemporary evolutionary responses to increased CO 2 have yet to be demonstrated in the field. At a Mojave Desert FACE (free‐air CO 2 enrichment) facility, we tested whether an annual grass weed ( Bromus madritensis ssp. rubens) has evolved in response to elevated atmospheric CO 2. Within 7 years, field populations exposed to elevated CO 2 evolved lower rates of leaf stomatal conductance; a physiological adaptation known to conserve water in other desert or water‐limited ecosystems. Evolution of lower conductance was accompanied by reduced plasticity in upregulating conductance when CO 2 was more limiting; this reduction in conductance plasticity suggests that genetic assimilation may be ongoing. Reproductive fitness costs associated with this reduction in phenotypic plasticity were demonstrated under ambient levels of CO 2. Our findings suggest that contemporary evolution may facilitate this invasive species' spread in this desert ecosystem. 相似文献
4.
Summary Routine field determination of the parameters characterizing the activity of the photosynthetic apparatus is often difficult when attached branches of tall trees have to be used for gas exchange measurement. If severed twigs could be used, determining these parameters would be greatly facilitated. Because stomatal conductance changes when twigs or leaves are detached, CO 2 assimilation is usually altered. Thus, measurements made at ambient CO 2 concentration fail to accurately assess the activity of the photosynthetic apparatus because photosynthetic rates greatly depend on the supply of carbon dioxide. However, when photosynthetic carboxylation reactions are saturated by increased CO 2 partial pressure in the mesophyll, CO 2 assimilation rates no longer depend on instantaneous stomatal conductance, as shown by gas exchange measurements of spruce ( Picea abies) twigs prior to and following detachment. Because net photosynthesis following detachment at saturating CO 2 remains constant for a minimum of 15 min, photosynthetic measurements of severed twigs may be reliable. This length of time is sufficient for detaching and recutting the twig, assembling a portable minicuvette system, re-establishing steady-state conditions with the gas analyser system, and reading the data over a reasonable period of time. The method described measures the maximal photosynthetic CO 2 assimilation of spruce needles of a single age-class from detached spruce twigs under the following conditions: saturating light, saturating external CO 2-partial pressure, standardized temperature and air humidity in the field. The method is applicable as a routine procedure to characterize the status of the photosynthetic apparatus of spruce trees that may be damaged in the process of forest decline. 相似文献
5.
It is generally thought that the terrestrial atmosphere at the time of the origin of life was CO 2-rich and that organic compounds such as amino acids would not have been efficiently formed abiotically under such conditions. It has been pointed out, however, that the previously reported low yields of amino acids may have been partially due to oxidation by nitrite/nitrate during acid hydrolysis. Specifically, the yield of amino acids was found to have increased significantly (by a factor of several hundred) after acid hydrolysis with ascorbic acid as an oxidation inhibitor. However, it has not been shown that CO 2 was the carbon source for the formation of the amino acids detected after acid hydrolysis with ascorbic acid. We therefore reinvestigated the prebiotic synthesis of amino acids in a CO 2-rich atmosphere using an isotope labeling experiment. Herein, we report that ascorbic acid does not behave as an appropriate oxidation inhibitor, because it contributes amino acid contaminants as a consequence of its reactions with the nitrogen containing species and formic acid produced during the spark discharge experiment. Thus, amino acids are not efficiently formed from a CO 2-rich atmosphere under the conditions studied. 相似文献
6.
The photosynthetic gas-exchange has been assessed traditionally either as O 2 evolution or CO 2 consumption. In this study, we used a liquid-phase O 2 electrode combined with CO 2 optodes to examine simultaneously photosynthesis in intact leaves of mangrove Rhizophora mucronata. We verified suitable conditions for leaf photosynthetic rates by assessing pH levels and NaHCO 3 concentrations and compared these to the gas-exchange method at various PAR levels. The photosynthetic rate in response to pH exhibited a similar pattern both for O 2 evolution and CO 2 consumption, and higher rates were associated with intermediate pH compared with low and high pH values. The net photosynthetic quotient (PQ) of R. mucronata leaves ranged from 1.04–1.28. The PQ values, which were never lesser than 1, suggested that photorespiration did not occur in R. mucronata leaves under aqueous conditions. The similar maximum photosynthetic rates suggested that all measurements had a high capacity to adjust the photosynthetic apparatus under a light saturation condition. The simultaneous measurements of O 2 evolution and CO 2 consumption using the Clark oxygen electrode polarographic sensor with the CO 2 optode sensor provided a simple, stable, and precise measurement of PQ under aqueous and saturated light conditions. 相似文献
7.
The effect of elevated atmospheric CO 2 and nutrient supply on elemental composition and decomposition rates of tree leaf litter was studied using litters derived from birch ( Betula pendula Roth.) plants grown under two levels of atmospheric CO 2 (ambient and ambient +250 ppm) and two nutrient regimes in solar domes. CO 2 and nutrient treatments affected the chemical composition of leaves, both independently and interactively. The elevated CO 2 and unfertilized soil regime significantly enhanced lignin/N and C/N ratios of birch leaves. Decomposition was studied using field litter-bags, and marked differences were observed in the decomposition rates of litters derived from the two treatments, with the highest weight remaining being associated with litter derived from the enhanced CO 2 and unfertilized regime. Highly significant correlations were shown between birch litter decomposition rates and lignin/N and C/N ratios. It can be concluded, from this study, that at levels of atmospheric CO 2 predicted for the middle of the next century a deterioration of litter quality will result in decreased decomposition rates, leading to reduction of nutrient mineralization and increased C storage in forest ecosystems. However, such conclusions are difficult to generalize, since tree responses to elevated CO 2 depend on soil nutritional status. 相似文献
8.
‘Blue Carbon’, which is carbon captured by marine living organisms, has recently been highlighted as a new option for climate change mitigation initiatives. In particular, coastal ecosystems have been recognized as significant carbon stocks because of their high burial rates and long‐term sequestration of carbon. However, the direct contribution of Blue Carbon to the uptake of atmospheric CO 2 through air‐sea gas exchange remains unclear. We performed in situ measurements of carbon flows, including air‐sea CO 2 fluxes, dissolved inorganic carbon changes, net ecosystem production, and carbon burial rates in the boreal (Furen), temperate (Kurihama), and subtropical (Fukido) seagrass meadows of Japan from 2010 to 2013. In particular, the air‐sea CO 2 flux was measured using three methods: the bulk formula method, the floating chamber method, and the eddy covariance method. Our empirical results show that submerged autotrophic vegetation in shallow coastal waters can be functionally a sink for atmospheric CO 2. This finding is contrary to the conventional perception that most near‐shore ecosystems are sources of atmospheric CO 2. The key factor determining whether or not coastal ecosystems directly decrease the concentration of atmospheric CO 2 may be net ecosystem production. This study thus identifies a new ecosystem function of coastal vegetated systems; they are direct sinks of atmospheric CO 2. 相似文献
9.
1. The pH in the stroma and in the thylakoid space has been measured in a number of chloroplast preparations in the dark and in the light at 20 °C. Illumination causes a decrease of the pH in the thylakoid space by 1.5 and an increase of the pH in the stroma by almost 1 pH unit.2. CO 2 fixation is shown to be strongly dependent on the pH in the stroma. The pH optimum was 8.1, with almost zero activity below pH 7.3. Phosphoglycerate reduction, which is a partial reaction of CO 2 fixation, shows very little pH dependency.3. Low concentrations of the uncoupler m-chlorocarbonylcyanide phenylhydrazone (CCCP) inhibit CO 2 fixation without affecting phosophoglycerate reduction. This inhibition of CO 2 fixation appears to be caused by reversal of light induced alkalisation in the stroma by CCCP.4. Methylamine has a very different effect compared to CCCP. Increasing concentrations of methylamine inhibit CO 2 fixation and phosphoglycerate reduction to the same extent. The light induced alkalisation of the stroma appears not to be significantly inhibited by methylamine, but the protons in the thylakoid space are neutralized. The inhibition of CO 2 fixation by higher concentrations of methylamine is explained by an inhibition of photophosphorylation. It appears that methylamine does not abolish proton transport.5. It is shown that intact chloroplasts are able to fix CO 2 in the dark, yielding 3-phosphoglycerate. This requires the addition of dihydroxyacetone phosphate as precursor of ribulosemonophosphate and also to supply ATP, and the addition of oxaloacetate for reoxidation of the NADPH in the stroma.6. Dark CO 2 fixation in the presence of dihydroxyacetone phosphate and oxaloacetate has the same pH dependency as CO 2 fixation in the light. This demonstrates that CO 2 fixation in the dark is not possible, unless the pH in the medium is artificially raised to pH 8.8.7. It is shown that pH changes occurring in the stroma after illumination are sufficient to switch CO 2 fixation from zero to maximal activity. This offers a mechanism for light control of CO 2 fixation, avoiding wasteful CO 2 fixation in the dark. 相似文献
10.
关于氮素对高大气CO 2浓度下C 3植物光合作用适应现象的调节机理已有较为深入的研究, 但对其光合作用适应现象的光合能量转化和分配机制缺乏系统分析。该文以大气CO 2浓度和施氮量为处理手段, 通过测定小麦( Triticum aestivum)抽穗期叶片的光合作用-胞间CO 2浓度响应曲线以及荧光动力学参数来测算光合电子传递速率和分配去向, 研究了长期高大气CO 2浓度下小麦叶片光合电子传递和分配对施氮量的响应。结果表明, 与正常大气CO 2浓度处理相比, 高大气CO 2浓度下小麦叶片较多的激发能以热量的形式耗散, 增施氮素可使更多的激发能向光化学反应方向的分配, 降低光合能量的热耗散速率; 大气CO 2浓度升高后小麦叶片光化学淬灭系数无明显变化, 高氮叶片的非光化学猝灭降低而低氮叶片明显升高, 施氮促进PSII反应中心的开放比例, 降低光能的热耗散; 高大气CO 2浓度下高氮叶片通过PSII反应中心的光合电子传递速率( JF)较高, 而且参与光呼吸的非环式电子流速率( J0)显著降低, 较正常大气CO 2浓度处理的高氮叶片下降了88.40%, 光合速率增加46.47%; 高大气CO 2浓度下小麦叶片 JF- J0升高而 J0/ JF显著下降, 光呼吸耗能被抑制, 更多的光合电子分配至光合还原过程。因此, 大气CO 2浓度增高条件下, 小麦叶片激发能的热耗散速率增加, 但增施氮素后小麦叶片PSII反应中心开放比例提高, 光化学速率增加, 进入PSII反应中心的电子流速率明显升高, 光呼吸作用被抑制, 光合电子较多地进入光化学过程, 这可能是高氮条件下光合作用适应性下调被缓解的一个原因。 相似文献
11.
The limiting step of photosynthesis changes depending on CO 2 concentration and, in theory, photosynthetic nitrogen use efficiency at a respective CO 2 concentration is maximized if nitrogen is redistributed from non‐limiting to limiting processes. It has been shown that some plants increase the capacity of ribulose‐1,5‐bisphoshate (RuBP) regeneration (evaluated as J max) relative to the RuBP carboxylation capacity (evaluated as V cmax) at elevated CO 2, which is in accord with the theory. However, there is no study that tests whether this change is accompanied by redistribution of nitrogen in the photosynthetic apparatus. We raised a perennial plant, Polygonum sachalinense, at two nutrient availabilities under two CO 2 concentrations. The J max to V cmax ratio significantly changed with CO 2 increment but the nitrogen allocation among the photosynthetic apparatus did not respond to growth CO 2. Enzymes involved in RuBP regeneration might be more activated at elevated CO 2, leading to the higher J max to V cmax ratio. Our result suggests that nitrogen partitioning is not responsive to elevated CO 2 even in species that alters the balance between RuBP regeneration and carboxylation. Nitrogen partitioning seems to be conservative against changes in growth CO 2 concentration. 相似文献
12.
Three allelic mutants of Arabidopsis thaliana which lack mitochondrial serine transhydroxymethylase activity due to a recessive nuclear mutation have been characterized. The mutants were shown to be deficient both in glycine decarboxylation and in the conversion of glycine to serine. Glycine accumulated as an end product of photosynthesis in the mutants, largely at the expense of serine, starch, and sucrose formation. The mutants photorespired CO 2 at low rates in the light, but this evolution of photorespiratory CO 2 was abolished by provision of exogenous NH 3. Exogenous NH 3 was required by the mutants for continued synthesis of glycine under photorespiratory conditions. These and related results with wild-type Arabidopsis suggested that glycine decarboxylation is the sole site of photorespiratory CO 2 release in wild-type plants but that depletion of the amino donors required for glyoxylate amination may lead to CO 2 release from direct decarboxylation of glyoxylate. Photosynthetic CO 2 fixation was inhibited in the mutants under atmospheric conditions which promote photorespiration but could be partially restored by exogenous NH 3. The magnitude of the NH 3 stimulation of photosynthesis indicated that the increase was due to the suppression of glyoxylate decarboxylation. The normal growth of the mutants under nonphotorespiratory atmospheric conditions indicates that mitochondrial serine transhydroxymethylase is not required in C 3 plants for any function unrelated to photorespiration. 相似文献
13.
Plant responses to elevated atmospheric CO 2 have been characterized generally by stomatal closure and enhanced growth rates. These responses are being increasingly incorporated into global climate models that quantify interactions between the biosphere and atmosphere, altering climate predictions from simpler physically based models. However, current information on CO 2 responses has been gathered primarily from studies of crop and temperate forest species. In order to apply responses of vegetation to global predictions, CO 2 responses in other commonly occurring biomes must be studied. A Free Air CO 2 Enrichment (FACE) study is currently underway to examine plant responses to high CO 2 in a natural, undisturbed Mojave Desert ecosystem in Nevada, USA. Here we present findings from this study, and its companion glasshouse experiment, demonstrating that field‐grown Ephedra nevadensis and glasshouse‐grown Larrea tridentata responded to high CO 2 with reductions in the ratio of transpirational surface area to sapwood area (LSR) of 33% and 60%, respectively. Thus, leaf‐specific hydraulic conductivity increased and stomatal conductance remained constant or was increased under elevated CO 2. Field‐grown Larrea did not show a reduced LSR under high CO 2, and stomatal conductance was reduced in the high CO 2 treatment, although the effect was apparent only under conditions of unusually high soil moisture. Both findings suggest that the common paradigm of 20–50% reductions in stomatal conductance under high CO 2 may not be applicable to arid ecosystems under most conditions. 相似文献
14.
Attempts are being made to introduce C 4 photosynthetic characteristics into C 3 crop plants by genetic manipulation. This research has focused on engineering single‐celled C 4‐type CO 2 concentrating mechanisms into C 3 plants such as rice. Herein the pros and cons of such approaches are discussed with a focus on CO 2 diffusion, utilizing a mathematical model of single‐cell C 4 photosynthesis. It is shown that a high bundle sheath resistance to CO 2 diffusion is an essential feature of energy‐efficient C 4 photosynthesis. The large chloroplast surface area appressed to the intercellular airspace in C 3 leaves generates low internal resistance to CO 2 diffusion, thereby limiting the energy efficiency of a single‐cell C 4 concentrating mechanism, which relies on concentrating CO 2 within chloroplasts of C 3 leaves. Nevertheless the model demonstrates that the drop in CO 2 partial pressure, pCO 2, that exists between intercellular airspace and chloroplasts in C 3 leaves at high photosynthetic rates, can be reversed under high irradiance when energy is not limiting. The model shows that this is particularly effective at lower intercellular pCO 2. Such a system may therefore be of benefit in water‐limited conditions when stomata are closed and low intercellular pCO 2 increases photorespiration. 相似文献
15.
Experiments have been done to confirm the previously reported effect of indoleacetic acid (IAA) on the rate of CO 2 assimilation in bean leaves. It was shown that spraying the leaves of a variety of plants caused an increase in the rate of CO 2 assimilation from 30% to 100% during the half-hour to 1 hour period following spraying. The only plant tested which did not show such an effect was corn. The breaking of dormancy of axial buds in the bean plant was correlated with an increase in the rate of CO2 assimilation in adjacent leaves for a brief period of time. It has been shown that IAA solution sprayed on 1 leaflet of a leaf can cause an increase in the rate of CO2 assimilation in the other leaflets, and that IAA applied to the cut stem of a leaflet or a developing bud can be transported to adjacent leaves and cause an increase in the CO2 assimilation rate. The reaction caused by IAA is very similar to that caused by the breaking of dormancy of a bud. This indicates that the bud break response in CO2 assimilation in leaves is caused by auxin synthesized in a bud as it begins to grow, and exported into adjacent leaves. 相似文献
16.
Few of the most common assumptions used in models of responses of plants and ecosystems to elevated CO 2 and climate warming have been tested under realistic life con-ditions. It is shown that some unexpected discrepancies between predictions and experimental findings exist, suggesting that a better empirical basis is required for predictions. The following ten suggestions may improve our potential to scale up from experimental scales to the real world. (1) Experiments should be timed to account for non-linearity in system responsiveness, asynchrony of responses and developmental differences. (2) By altering mineral nutrient supply, a wide range of CO 2 responses can be ‘produced’, thus requiring realistic soil conditions. (3) Distinctions should be made between ‘doubling CO 2 sup-ply’ and biologically effective degrees of CO 2 enrichment. (4) Because of the non-linearity of plant responses to CO 2, studies of at least three instead of two CO2 concentrations are necessary to describe future trends adequately. (5) Edge effects, in particular unscreened side light, may lead to allometric anomalies, strongly constraining up-scaling to stand-scale CO 2 responses. (6) Variables such as growth, yield, net primary production and C turnover are often confused with carbon pools, carbon sequestration or net ecosystem production. (7) Mono- and interspecific interactions between individuals may lead to completely unpredictable CO 2 responses. (8) Experiments with seedlings benefit from the absence of prehistory effects but are likely to be irrelevant for the responses of larger trees which, on the other hand, may be constrained by carry-over effects. Tree ring research indicates immediate sensitivity of large trees to environmental changes, supporting their usefulness in short-term CO 2-enrichment experiments. (9) In predicting temperature responses, acclimation deserves more attention. (10) The significance of developmental responses is largely under-represented in experimental research, although these responses may overrule many of the other effects of atmospheric change. Results of more realistic experiments which account for these problems will provide a better basis for modelling the future of the biosphere. 相似文献
17.
An advanced radiogasometric method for the study of plant leaf CO 2 exchange is presented. The method enables determination of the rates of CO 2 fixation, photorespiration and respiration in the light under steady‐state photosynthesis and discrimination between primary and stored photosynthates as substrates of photorespiratory and respiratory decarboxylations. The method is based on the analysis of the time curves of 14CO 2 evolution from labeled primary and stored photosynthates in leaves previously exposed to 14CO 2. The molar rates of different decarboxylation reactions are calculated from the initial slopes of the curves taking into account the specific radioactivity of CO 2 fed to leaves and/or evolved from leaves. To estimate the contribution of primary and stored photosynthates, the measurements of 14CO 2 evolution are performed after feeding plant leaves for different periods with 14CO 2. Photorespiration and respiration are distinguished on the basis of data obtained from measurements of 14CO 2 evolution under normal (210 ml l −1) and low (15 ml l −1) concentrations of oxygen. A principally new method for the determination of the rate of intracellular refixation of respiratory CO 2 has been developed. The method is based on the measurements of 14CO 2 evolution from leaves into the medium of very high concentrations (30 ml l −1) of 12CO 2, where the probability of refixation of 14CO 2 evolved inside the cell is close to zero. The results obtained were comparable with the data derived from parallel refixation measurements by means of gasometric methods. As an example of application, the data on CO 2 exchange in leaves of two contrasting groups of C 3‐species, differing in the ability of starch accumulation, are presented. 相似文献
18.
An essential component of an understanding of carbon flux is the quantification of movement through the root carbon pool. Although estimates have been made using radiocarbon, the use of minirhizotrons provides a direct measurement of rates of root birth and death. We have measured root demographic parameters under a semi-natural grassland and for wheat. The grassland was studied along a natural altitudinal gradient in northern England, and similar turf from the site was grown in elevated CO 2 in solardomes. Root biomass was enhanced under elevated CO 2. Root birth and death rates were both increased to a similar extent in elevated CO 2, so that the throughput of carbon was greater than in ambient CO 2, but root half-lives were shorter under elevated CO 2 only under a Juncus/Nardus sward on a peaty gley soil, and not under a Festuca turf on a brown earth soil. In a separate experiment, wheat also responded to elevated CO 2 by increased root production, and there was a marked shift towards surface rooting: root development at a depth of 80–85 cm was both reduced and delayed. In conjunction with published results for trees, these data suggest that the impact of elevated CO 2 will be system-dependent, affecting the spatio-temporal pattern of root growth in some ecosystems and the rate of turnover in others. Turrnover is also sensitive to temperature, soil fertility and other environmental variables, all of which are likely to change in tandem with atmospheric CO 2 concentrations. Differences in turnover and time and location of rhizodeposition may have a large effect on rates of carbon cycling. 相似文献
19.
Summary The production of organic matter by phytoplankton in Søllerød Sø, which receives large amounts of purified sewage, has been determined at 1300 g glucose per sq. m and year. A maximum of 9.5 g per sq. m is reached per day. It is shown that the yearly production in a lake of this type presumably cannot be considerably greater as through the consumption of carbon dioxide pH will increase to such a degree that this factor becomes injurious to the plankton algae. The uptake of CO 2 from the atmosphere whereby pH is lowered thus is the real limiting factor for the production of organic matter in the lake. During the height of summer between 60 and 100 g CO 2 is absorbed from the atmosphere per sq. m surface per month. 相似文献
20.
We examined whether the effects of elevated CO 2 on growth of 1-year old Populus deltoides saplings was a function of the assimilation responses of particular leaf developmental stages. Saplings were grown for 100 days
at ambient (approximately 350 ppm) and elevated (ambient + 200 ppm) CO 2 in forced-air greenhouses. Biomass, biomass distribution, growth rates, and leaf initiation and expansion rates were unaffected
by elevated CO 2. Leaf nitrogen (N), the leaf C:N ratio, and leaf lignin concentrations were also unaffected. Carbon gain was significantly
greater in expanding leaves of saplings grown at elevated compared to ambient CO 2. The Rubisco content in expanding leaves was not affected by CO 2 concentration. Carbon gain and Rubisco content were significantly lower in fully expanded leaves of saplings grown at elevated
compared to ambient CO 2, indicating CO 2-induced down-regulation in fully expanded leaves. Elevated CO 2 likely had no overall effect on biomass accumulation due to the more rapid decline in carbon gain as leaves matured in saplings
grown at elevated compared to ambient CO 2. This decline in carbon gain has been documented in other species and shown to be related to a balance between sink/source
balance and acclimation. Our data suggest that variation in growth responses to elevated CO 2 can result from differences in leaf assimilation responses in expanding versus expanded leaves as they develop under elevated
CO 2.
Received: 28 September 1998 / Accepted: 23 June 1999 相似文献
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