scholarly journals Acclimation of Plant Populations to Shade: Photosynthesis, Respiration, and Carbon Use Efficiency

2005 ◽  
Vol 130 (6) ◽  
pp. 918-927 ◽  
Author(s):  
Jonathan M. Frantz ◽  
Bruce Bugbee
Keyword(s):  
Growth Models ◽  
Photon Flux ◽  
Carbon Gain ◽  
Low Light ◽  
Carbon Use Efficiency ◽  
Grand Rapids ◽  
Use Efficiency ◽  
Gas Exchange System ◽  
Photosynthesis And Respiration

Cloudy days cause an abrupt reduction in daily photosynthetic photon flux (PPF), but we have a poor understanding of how plants acclimate to this change. We used a unique 10-chamber, steady-state, gas-exchange system to continuously measure daily photosynthesis and night respiration of populations of a starch accumulator [tomato (Lycopersicon esculentum Mill. cv. Micro-Tina)] and a sucrose accumulator [lettuce (Lactuca sativa L. cv. Grand Rapids)] over 42 days. All measurements were done at elevated CO2 (1200 μmol·mol-1) to avoid any CO2 limitations and included both shoots and roots. We integrated photosynthesis and respiration measurements separately to determine daily net carbon gain and carbon use efficiency (CUE) as the ratio of daily net C gain to total day-time C fixed over the 42-day period. After 16 to 20 days of growth in constant PPF, plants in some chambers were subjected to an abrupt PPF reduction to simulate shade or a series of cloudy days. The immediate effect and the long term acclimation rate were assessed from canopy quantum yield and carbon use efficiency. The effect of shade on carbon use efficiency and acclimation was much slower than predicted by widely used growth models. It took 12 days for tomato populations to recover their original CUE and lettuce CUE never completely acclimated. Tomatoes, the starch accumulator, acclimated to low light more rapidly than lettuce, the sucrose accumulator. Plant growth models should be modified to include the photosynthesis/respiration imbalance and resulting inefficiency of carbon gain associated with changing PPF conditions on cloudy days.

scholarly journals Light Effects on Wax Begonia: Photosynthesis, Growth Respiration, Maintenance Respiration, and Carbon Use Efficiency

2004 ◽  
Vol 129 (3) ◽  
pp. 416-424 ◽  
Author(s):  
Krishna S. Nemali ◽  
M.W. van Iersel
Keyword(s):  
Growth Period ◽  
Dry Weight ◽  
Carbon Gain ◽  
Maintenance Respiration ◽  
Gross Photosynthesis ◽  
Carbon Use Efficiency ◽  
Whole Plant ◽  
Growth Respiration ◽  
Use Efficiency ◽  
Gas Exchange System

The effect of increasing daily light integral (DLI; 5.3, 9.5, 14.4, and 19.4 mol·m-2·d-1) on photosynthesis and respiration of wax begonia (Begonia semperflorens-cultorum Hort.) was examined by measuring CO2 exchange rates (CER) for a period of 25 d in a whole-plant gas exchange system. Although plant growth rate (GR, increase in dry weight per day) increased linearly with increasing DLI, plants grown at low DLI (5.3 or 9.5 mol·m-2·d-1) respired more carbohydrates than were fixed in photosynthesis during the early growth period (13 and 4 d, respectively), resulting in a negative daily carbon gain (DCG) and GR. Carbon use efficiency [CUE, the ratio of carbon incorporated into the plant to C fixed in gross photosynthesis (Pg)] of plants grown at low DLI was low, since these plants used most of the C fixed in Pg for maintenance respiration (Rm), leaving few, if any, C for growth and growth respiration (Rg). Maintenance respiration accounted for a smaller fraction of the total respiration with increasing DLI. In addition, the importance of Rm in the carbon balance of the plants decreased over time, resulting in an increase in CUE. At harvest, crop dry weight (DWCROP) increased linearly with increasing DLI, due to the increased photosynthesis and CUE at high PPF.

scholarly journals Growth Respiration, Maintenance Respiration, and Carbon Fixation of Vinca: A Time Series Analysis

2000 ◽  
Vol 125 (6) ◽  
pp. 702-706 ◽  
Author(s):  
Marc W. van Iersel ◽  
Lynne Seymour
Keyword(s):  
Carbon Balance ◽  
Carbon Fixation ◽  
Plant Size ◽  
Carbon Gain ◽  
Maintenance Respiration ◽  
Carbon Use Efficiency ◽  
Size Growth ◽  
Growth Respiration ◽  
Use Efficiency ◽  
Traditional Approaches

Respiration is important in the overall carbon balance of plants, and can be separated into growth (Rg) and maintenance respiration (Rm). Estimation of Rg and Rm throughout plant development is difficult with traditional approaches. Here, we describe a new method to determine ontogenic changes in Rg and Rm. The CO2 exchange rate of groups of 28 `Cooler Peppermint' vinca plants [Catharanthus roseus (L.) G. Don.] was measured at 20 min intervals for 2 weeks. These data were used to calculate daily carbon gain (DCG, a measure of growth rate) and cumulative carbon gain (CCG, a measure of plant size). Growth and maintenance respiration were estimated based on the assumption that they are functions of DCG and CCG, respectively. Results suggested a linear relationship between DCG and Rg. Initially, Rm was three times larger than Rg, but they were similar at the end of the experiment. The decrease in the fraction of total available carbohydrates that was used for Rm resulted in an increase in carbon use efficiency from 0.51 to 0.67 mol·mol-1 during the 2-week period. The glucose requirement of the plants was determined from Rg, DCG, and the carbon fraction of the plant material and estimated to be 1.39 g·g-1, while the maintenance coefficient was estimated to be 0.031 g·g-1·d-1 at the end of the experiment. These results are similar to values reported previously for other species. This suggests that the use of semicontinuous CO2 exchange measurements for estimating Rg and Rm yields reasonable results.

Assessment of depth‐dependent microbial carbon‐use efficiency in long‐term fertilized paddy soil using an 18 O–H 2 O approach

2020 ◽  
Vol 32 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Mostafa Zhran ◽  
Tida Ge ◽  
Yaoyao Tong ◽  
Yangwu Deng ◽  
Xiaomeng Wei ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Carbon Use Efficiency ◽  
Microbial Carbon ◽  
Use Efficiency ◽  
Microbial Carbon Use Efficiency

scholarly journals Canopy Photosynthesis and Time-of-day Application of Supplemental Light

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1284-1290 ◽  
Author(s):  
Jakob Markvart ◽  
Eva Rosenqvist ◽  
Helle Sørensen ◽  
Carl-Otto Ottosen ◽  
Jesper M. Aaslyng
Keyword(s):  
Dark Respiration ◽  
High Growth ◽  
Net Photosynthesis ◽  
Time Of Day ◽  
Photon Flux ◽  
Carbon Gain ◽  
Climate Control ◽  
Low Light ◽  
Light Intensities ◽  
Supplemental Lighting

There is increasing use of electricity for supplemental lighting in the northern European greenhouse industry. One reason for this may be to secure a high growth rate during low-light periods by an attempt to increase net photosynthesis. We wanted to clarify which period of the day resulted in the best use of a 5-h supplemental light period for photosynthesis and growth. The periods tested were supplemental light during the night, day, morning, and evening. The experiments were carried out in daylight climate chambers measuring canopy gas exchange. The air temperature was 25 °C and the CO2 level ≈900 ppm. Vegetative chrysanthemum was used, because this species responds quickly to change in light level. The leaf areas of the plant canopies were nondestructively measured each week during the 4-week experimental period. The fact that the quantum yield of photosynthesis is greater at low than at high light intensities favors the use of supplemental light during the dark period, but growth measured as dry weight of the treated plants at the end of the experiments was not significantly different given identical light integrals of the treatments. However, one experiment indicated that increased time with dark hours during day and night (24 h) might decrease net photosynthesis. The assimilation per unit leaf area was approximately the same during times of sunlight through a diffusing screen at 100 μmol·m−2·s−1 of photosynthetic photon flux (PPF) as during times of supplemental (direct) light application at PPF of 200 μmol·m−2·s−1 by high-pressure sodium lamps. We conclude that during the winter and periods of low light intensities, the daily carbon gain does not depend on the time of supplemental light application, but is linked to the total light integral. However, extended time with dark hours during day and night (24 h) might be a disadvantage because of longer periods with dark respiration and subsequent loss of carbon. Our results indicate that during times of low light conditions, it is not necessary to include factors such as the timing of supplemental lighting application to achieve higher net photosynthesis in climate control strategies.

Growth and photosynthesis of Aechmea magdalenae, a terrestrial CAM plant in a tropical moist forest, Panama

1988 ◽  
Vol 4 (2) ◽  
pp. 199-207 ◽  
Author(s):  
William A. Pfitsch ◽  
Alan P. Smith
Keyword(s):  
Growth Rates ◽  
Forest Growth ◽  
Barro Colorado Island ◽  
Photon Flux ◽  
Carbon Gain ◽  
Canopy Openness ◽  
Wet Season ◽  
Low Light ◽  
Primary Means ◽  
Aechmea Magdalenae

ABSTRACTAechmea magdalenae is a terrestrial bromeliad that dominates areas of forest understorey on Barro Colorado Island, Panama. Nocturnal CO2 uptake via crassulacean acid metabolism was the primary means of carbon gain under well-watered conditions and all light regimes. The ability to maintain a positive carbon balance under conditions of very low light was demonstrated by laboratory measurements of photosynthesis and forest measurements of growth. Low-light-grown juvenile rosettes had the same daily net assimilation whether tested at photon flux densities of 15 or 300 μmol m−2 s−1 Growth rates of rosettes in treefall gaps were similar to those of plants in closed canopy forest. Growth rates of forest plants were increasingly correlated with canopy openness as the wet season progressed due to increased growth by gap plants, suggesting that water availability rather than light may limit growth during the annual dry season.

scholarly journals Assessing microbial residues in soil as a potential carbon sink and moderator of carbon use efficiency

2020 ◽  
Vol 151 (2-3) ◽  
pp. 237-249
Author(s):  
Kevin Geyer ◽  
Jörg Schnecker ◽  
A. Stuart Grandy ◽  
Andreas Richter ◽  
Serita Frey
Keyword(s):  
Microbial Biomass ◽  
Carbon Sink ◽  
Meta Analysis ◽  
Clay Content ◽  
Tracer Experiment ◽  
Carbon Use Efficiency ◽  
Sequestration Potential ◽  
Use Efficiency ◽  
Microbial Products

AbstractA longstanding assumption of glucose tracing experiments is that all glucose is microbially utilized during short incubations of ≤2 days to become microbial biomass or carbon dioxide. Carbon use efficiency (CUE) estimates have consequently ignored the formation of residues (non-living microbial products) although such materials could represent an important sink of glucose that is prone to stabilization as soil organic matter. We examined the dynamics of microbial residue formation from a short tracer experiment with frequent samplings over 72 h, and conducted a meta-analysis of previously published glucose tracing studies to assess the generality of these experimental results. Both our experiment and meta-analysis indicated 30–34% of amended glucose-C (13C or 14C) was in the form of residues within the first 6 h of substrate addition. We expand the conventional efficiency calculation to include residues in both the numerator and denominator of efficiency, thereby deriving a novel metric of the potential persistence of glucose-C in soil as living microbial biomass plus residues (‘carbon stabilization efficiency’). This new metric indicates nearly 40% of amended glucose-C persists in soil 180 days after amendment, the majority as non-biomass residues. Starting microbial biomass and clay content emerge as critical factors that positively promote such long term stabilization of labile C. Rapid residue production supports the conclusion that non-growth maintenance activity can illicit high demands for C in soil, perhaps equaling that directed towards growth, and that residues may have an underestimated role in the cycling and sequestration potential of C in soil.

Stomatal conductance and transpiration in shoots of Scots pine after 4-year exposure to elevated CO2 and temperature

1997 ◽  
Vol 75 (4) ◽  
pp. 552-561 ◽  
Author(s):  
Kai-Yun Wang ◽  
Seppo Kellomäki
Keyword(s):  
Elevated Temperature ◽  
Stomatal Conductance ◽  
Pinus Sylvestris ◽  
Water Use Efficiency ◽  
Water Use ◽  
Photon Flux ◽  
Absolute Value ◽  
Use Efficiency ◽  
The Absolute

Single Scots pines (Pinus sylvestris L.) trees were subjected to elevated temperature (year-round elevation), elevated CO2 (elevation from April 15 to September 15), and a combination of elevated temperature and CO2, for 4 years in open-topped chambers. Measurements and modelling were performed to determine if long-term growth at elevated CO2 concentration and temperature altered water use efficiency (WE) and the responses of stomatal conductance (gs) to photon flux density (Qp), the leaf-to-air vapour pressure difference (Dv), leaf temperature (Tl), and intercellular concentration of CO2 (Ci). Long-term elevation of CO2 led to a significant decline in the absolute value of gs at almost all levels of Qp, Dv, Ci, and Tl. Elevated temperature treatment increased the absolute value of gs only at higher Dv and Tl. The effect of the combination of elevated CO2 and temperature did not appear as a mean of the effects of the two single factors, while there was an interaction between the two factors. The modifications in the sensitivity of stomata, resulting from different treatments, did not have the same pattern as the change in gs, but depended on levels of Qp, Dv, and Tl. Compared with the control treatment, elevated concentration of CO2 or a combination of elevated CO2 and temperature led, on average, to 50 and 30% increases in WE, respectively, which can be attributed mainly to an increase in the rate of net assimilation. In contrast, elevated temperature alone did not significantly change WE, although transpiration rate was increased. Key words: long-term CO2 and temperature elevation, stomatal conductance, transpiration, water use efficiency, Pinus sylvestris.

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