scholarly journals Increased productivity of ryegrass grown at elevated CO2 is dependent on tillering and leaf area development rather than leaf-level photosynthesis

2020 ◽  
Author(s):  
Charilaos Yiotis ◽  
Jennifer C McElwain ◽  
Bruce A Osborne
Keyword(s):  
Leaf Area ◽  
Elevated Co2 ◽  
Growth Yield ◽  
Biomass Productivity ◽  
Co2 Concentration ◽  
Crop Productivity ◽  
Atmospheric Co2 ◽  
Leaf Photosynthesis ◽  
Diverse Range ◽  
Co2 Concentrations

Abstract Whilst a range of strategies have been proposed for enhancing crop productivity many recent studies have focussed primarily on enhancing leaf photosynthesis under current atmospheric CO2 concentrations. Given that the atmospheric CO2 concentration is likely to increase significantly in the foreseeable future an alternative/complementary strategy might be to exploit any variability in the enhancement of growth/yield and photosynthesis at higher CO2 concentrations. To explore this, we investigated the responses of a diverse range of wild and cultivated ryegrass genotypes, with contrasting geographical origins, to ambient and elevated CO2 concentrations and examined what genetically tractable plant trait(s) might be targeted by plant breeders for future yield enhancements. We found substantial ~7-fold intraspecific variations in biomass productivity among the different genotypes at both CO2 levels, which were related primarily to differences in tillering/leaf area, with only small differences due to leaf photosynthesis. Interestingly, the ranking of genotypes in terms of their response to both CO2 concentrations was similar. However, as expected, estimates of whole-plant photosynthesis were strongly correlated with plant productivity. Our results suggest that greater yield gains under elevated CO2 are likely through the exploitation of genetic differences in tillering and leaf area rather than focussing solely on improving leaf photosynthesis.

Carbon Di Oxide Fertilization: Effects on Plant Productivity

2017 ◽  
Vol 3 (02) ◽  
pp. 73-77
Author(s):  
Supriya Tiwari ◽  
N. K. Dubey
Keyword(s):  
Climate Change ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Plant Productivity ◽  
C4 Plants ◽  
Atmospheric Co2 ◽  
Growth And Yield ◽  
Co2 Fertilization ◽  
Co2 Concentrations ◽  
Fertilization Effect

Increasing Carbon dioxide (CO2) is an important component of global climate change that has drawn the attention of environmentalists worldwide in the last few decades. Besides acting as an important greenhouse gas, it also produces a stimulatory effect, its instantaneous impact being a significant increase in the plant productivity. Atmospheric CO2 levels have linearly increased from approximately 280 parts per million (ppm) during pre-industrial times to the current level of more than 390 ppm. In past few years, anthropogenic activities led to a rapid increase in global CO2 concentration. Current Intergovernmental Panel on Climate Change (IPCC) projection indicates that atmospheric CO2 concentration will increase over this century, reaching 730-1020 ppm by 2100. An increase in global temperature, ranging from 1.1 to 6.4oC depending on global emission scenarios, will accompany the rise in atmospheric CO2. As CO2 acts as a limiting factor in photosynthesis, the immediate effect of increasing atmospheric CO2 is improved plant productivity, a feature commonly termed as “CO2 fertilization”. Variability in crop responses to the elevated CO2 made the agricultural productivity and food security vulnerable to the climate change. Several studies have shown significant CO2 fertilization effect on crop growth and yield. An increase of 30 % in plant growth and yield has been reported when CO2 concentration has been doubled from 330 to 660 ppm. However, the fertilization effect of elevated CO2 is not very much effective in case of C4 plants which already contain a CO2 concentration mechanism, owing to their specific leaf 2 anatomy called kranz anatomy. As a result, yield increments observed in C4plants are comparatively lower than the C3 plants under similar elevated CO2 concentrations. This review discusses the trends and the causes of increasing CO2 concentration in the atmosphere, its effects on the crop productivity and the discrepancies in the response of C3 and C4 plants to increasing CO2 concentrations.

The impact of elevated atmospheric CO2 and nitrate supply on growth, biomass allocation, nitrogen partitioning and N2 fixation of Acacia melanoxylon

1999 ◽  
Vol 26 (8) ◽  
pp. 737 ◽  
Author(s):  
Marcus Schortemeyer ◽  
Owen K. Atkin ◽  
Nola McFarlane ◽  
John R. Evans
Keyword(s):  
Elevated Co2 ◽  
N2 Fixation ◽  
Dry Matter ◽  
Co2 Concentration ◽  
Dry Mass ◽  
Nitrogen Partitioning ◽  
Atmospheric Co2 ◽  
Acacia Melanoxylon ◽  
Nitrate Supply ◽  
The Impact

The interactive effects of nitrate supply and atmospheric CO2 concentration on growth, N2 fixation, dry matter and nitrogen partitioning in the leguminous tree Acacia melanoxylon R.Br. were studied. Seedlings were grown hydroponically in controlled-environment cabinets for 5 weeks at seven 15N-labelled nitrate levels, ranging from 3 to 6400 mmol m–3. Plants were exposed to ambient (~350 µmol mol–1) or elevated (~700 µmol mol–1) atmospheric CO2 for 6 weeks. Total plant dry mass increased strongly with nitrate supply. The proportion of nitrogen derived from air decreased with increasing nitrate supply. Plants grown under either ambient or elevated CO2 fixed the same amount of nitrogen per unit nodule dry mass (16.6 mmol N per g nodule dry mass) regardless of the nitrogen treatment. CO2 concentration had no effect on the relative contribution of N2 fixation to the nitrogen yield of plants. Plants grown with ≥50 mmol m–3 N and elevated CO2 had approximately twice the dry mass of those grown with ambient CO2 after 42 days. The rates of net CO2 assimilation under growth conditions were higher per unit leaf area for plants grown under elevated CO2. Elevated CO2 also decreased specific foliage area, due to an increase in foliage thickness and density. Dry matter partitioning between plant organs was affected by ontogeny and nitrogen status of the plants, but not by CO2 concentration. In contrast, plants grown under elevated CO2 partitioned more of their nitrogen to roots. This could be attributed to reduced nitrogen concentrations in foliage grown under elevated CO2.

scholarly journals Differential Growth Responses of Wheat Seedlings to Elevated CO2

2018 ◽  
Vol 10 (3) ◽  
pp. 400-409 ◽  
Author(s):  
Hamid Reza ESHGHIZADEH ◽  
Morteza ZAHEDI ◽  
Samaneh MOHAMMADI
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Tolerance Index ◽  
Dry Matter Accumulation ◽  
Wheat Cultivars ◽  
Growth Responses ◽  
Differential Growth ◽  
Wheat Seedlings

Intraspecific variations in wheat growth responses to elevated CO2 was evaluated using 20 Iranian bread wheat (Triticum aestivum L.) cultivars. The plants were grown in the modified Hoagland nutrient solution at a greenhouse until 35 days of age using two levels of CO2 (~380 and 700 µmol mol–1). The shoot and root dry weights of the wheat cultivars exhibited average enhancements of 17% and 36%, respectively, under elevated CO2. This increase was associated with higher levels of chlorophyll a (25%), chlorophyll b (21%), carotenoid (30%), leaf area (54%) and plant height (49.9%). The leaf area (r = 0.69**), shoot N content (r = 0.62**), plant height (r = 0.60**) and root volume (r = 0.53*) were found to have important roles in dry matter accumulation of tested wheat cultivars under elevated CO2 concentration. However, responses to elevated CO2 were considerably cultivar-dependent. Based on the stress susceptibility index (SSI) and stress tolerance index (STI), the wheat cultivars exhibiting the best response to elevated CO2 content were ‘Sistan’, ‘Navid’, ‘Shiraz’, ‘Sepahan’ and ‘Bahar’, while the ones with poor responses were ‘Omid’, ‘Marun’, ‘Sorkhtokhm’ and ‘Tajan’. The findings from the present experiment showed significant variation among the Iranian wheat cultivars in terms of their responses to elevated air CO2, providing the opportunity to select the most efficient ones for breeding purposes.

scholarly journals The sensitivity of stand-scale photosynthesis and transpiration to changes in atmospheric CO2 concentration and climate

1999 ◽  
Vol 3 (1) ◽  
pp. 55-69 ◽  
Author(s):  
B. Kruijt ◽  
C. Barton ◽  
A. Rey ◽  
P. G. Jarvis
Keyword(s):  
Water Stress ◽  
Nitrogen Content ◽  
Leaf Area ◽  
Water Use ◽  
N Uptake ◽  
Co2 Concentration ◽  
Picea Sitchensis ◽  
Atmospheric Co2 ◽  
Atmospheric Co2 Concentration ◽  
Needle Longevity

Abstract. The 3-dimensional forest model MAESTRO was used to simulate daily and annual photosynthesis and transpiration fluxes of forest stands and the sensitivity of these fluxes to potential changes in atmospheric CO2 concentration ([CO2]), temperature, water stress and phenology. The effects of possible feed-backs from increased leaf area and limitations to leaf nutrition were simulated by imposing changes in leaf area and nitrogen content. Two different tree species were considered: Picea sitchensis (Bong.) Carr., a conifer with long needle longevity and large leaf area, and Betula pendula Roth., a broad-leaved deciduous species with an open canopy and small leaf area. Canopy photosynthetic production in trees was predicted to increase with atmospheric [CO2] and length of the growing season and to decrease with increased water stress. Associated increases in leaf area increased production further only in the B. pendula canopy, where the original leaf area was relatively small. Assumed limitations in N uptake affected B. pendula more than P. sitchensis. The effect of increased temperature was shown to depend on leaf area and nitrogen content. The different sensitivities of the two species were related to their very different canopy structure. Increased [CO2] reduced transpiration, but larger leaf area, early leaf growth, and higher temperature all led to increased water use. These effects were limited by feedbacks from soil water stress. The simulations suggest that, with the projected climate change, there is some increase in stand annual `water use efficiency', but the actual water losses to the atmosphere may not always decrease.

scholarly journals Impact of elevated CO2 concentration on dynamics of leaf photosynthesis in Fagus sylvatica is modulated by sky conditions

2014 ◽  
Vol 185 ◽  
pp. 271-280 ◽  
Author(s):  
Otmar Urban ◽  
Karel Klem ◽  
Petra Holišová ◽  
Ladislav Šigut ◽  
Mirka Šprtová ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Fagus Sylvatica ◽  
Co2 Concentration ◽  
Leaf Photosynthesis ◽  
Elevated Co2 Concentration ◽  
Sky Conditions

scholarly journals Elevated CO2 Concentrations and Water Stress Affect the Ability of Italian Ryegrass to Remediate Herbicides and Enhance its Allelopathic Effect

2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  
Keyword(s):  
Water Stress ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Italian Ryegrass ◽  
Allelopathic Effect ◽  
Irrigated Rice ◽  
Allelopathic Potential ◽  
Co2 Concentrations ◽  
Temporal Persistence ◽  
The Impact

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.

Effects of elevated CO2 concentration and nitrogen addition on the chemical compositions, construction cost, and payback time of subtropical trees in Cd-contaminated mesocosm soil

2021 ◽  
Author(s):  
Xiaowei Zang ◽  
Xianzhen Luo ◽  
Enqing Hou ◽  
Guihua Zhang ◽  
Xiaofeng Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Elevated Co2 ◽  
Photosynthetic Rate ◽  
Tree Species ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Physiological Characteristics ◽  
Chemical Compositions ◽  
N Addition ◽  
Payback Time

Abstract Rising atmospheric CO2 concentration ([CO2]) and nitrogen (N) deposition are changing plant growth, physiological characteristics, and chemical compositions; however, few studies have explored such impacts in a heavy-metal-contaminated environment. In this study, we conducted an open-top chamber experiment to explore the impacts of two years of elevated atmospheric [CO2] and N addition on the growth, physiological characteristics, and chemical compositions of five subtropical tree species in a cadmium (Cd)-contaminated environment. Results showed that N addition significantly increased concentration of leaf N and protein in five tree species, and also decreased payback time (PBT) and leaf C:N ratios and increased tree relative height growth rate (RGR-H) and basal diameter growth rate (RGR-B) in Liquidambar formosana and Syzygium hainanense. Elevated [CO2] increased leaf maximum photosynthetic rate (Amax) and concentration of total non-structural carbohydrates (TNC) and shortened PBT to offset the negative effect of Cd contamination on RGR-B in A. auriculiformis. The combined effects of elevated [CO2] and N addition did not exceed their separate effects on RGR-H and RGR-B in Castanopsis hystrix and Cinnamomum camphora. N addition significantly increased the concentration of leaf Cd by 162.1% and 338.0%, and plant Cd bio-concentration factor (BCF) by 464% and 861% in C. hystrix, and C. camphora, respectively, compared to Cd addition. Among the five tree species, the decreases in PBT and the increases in Amax, RGR-B, and concentrations of leaf protein in response to N and Cd addition under elevated [CO2] were average higher 86.7% in A. auriculiformis than other species, suggesting that the mitigation of the negative effects of Cd pollution by elevated [CO2] and N addition among five species was species-specific. Overall, we concluded that N addition and elevated [CO2] reduced Cd toxicity, and increased the growth rate in A. auriculiformis, S. hainanense and L. formosana, while maintained the growth rate in C. hystrix, and C. camphora by differently increasing photosynthetic rate, altering the leaf chemical compositions, and shortening PBT.

scholarly journals Simulating Long-Term Development of Greenhouse Gas Emissions, Plant Biomass, and Soil Moisture of a Temperate Grassland Ecosystem under Elevated Atmospheric CO2

Agronomy ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 50
Author(s):  
Ralf Liebermann ◽  
Lutz Breuer ◽  
Tobias Houska ◽  
David Kraus ◽  
Gerald Moser ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Elevated Co2 ◽  
Biomass Production ◽  
Atmospheric Co2 ◽  
N2o Emissions ◽  
Gas Emissions ◽  
Co2 Concentrations

The rising atmospheric CO2 concentrations have effects on the worldwide ecosystems such as an increase in biomass production as well as changing soil processes and conditions. Since this affects the ecosystem’s net balance of greenhouse gas emissions, reliable projections about the CO2 impact are required. Deterministic models can capture the interrelated biological, hydrological, and biogeochemical processes under changing CO2 concentrations if long-term observations for model testing are provided. We used 13 years of data on above-ground biomass production, soil moisture, and emissions of CO2 and N2O from the Free Air Carbon dioxide Enrichment (FACE) grassland experiment in Giessen, Germany. Then, the LandscapeDNDC ecosystem model was calibrated with data measured under current CO2 concentrations and validated under elevated CO2. Depending on the hydrological conditions, different CO2 effects were observed and captured well for all ecosystem variables but N2O emissions. Confidence intervals of ensemble simulations covered up to 96% of measured biomass and CO2 emission values, while soil water content was well simulated in terms of annual cycle and location-specific CO2 effects. N2O emissions under elevated CO2 could not be reproduced, presumably due to a rarely considered mineralization process of organic nitrogen, which is not yet included in LandscapeDNDC.

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