Research note: Can decreased transpiration limit plant nitrogen acquisition in elevated CO2?

2002 ◽  
Vol 29 (9) ◽  
pp. 1115 ◽  
Author(s):  
Evan P. McDonald ◽  
John E. Erickson ◽  
Eric L. Kruger
Keyword(s):  
Stomatal Conductance ◽  
Elevated Co2 ◽  
Plant Biomass ◽  
Stomatal Closure ◽  
Co2 Enrichment ◽  
Root Mass ◽  
N Accumulation ◽  
Plant Nitrogen ◽  
N Concentration ◽  
N Acquisition

N acquisition often lags behind accelerated C gain in plants exposed to CO2-enriched atmospheres. To help resolve the causes of this lag, we considered its possible link with stomatal closure, a common first-order response to elevated CO2 that can decrease transpiration. Specifically, we tested the hypothesis that declines in transpiration, and hence mass flow of soil solution, can decrease delivery of mobile N to the root and thereby limit plant N acquisition. We altered transpiration by manipulating relative humidity (RH) and atmospheric [CO2]. During a 7-d period, we grew potted cottonwood (Populus deltoides Bartr.) trees in humidified (76% RH) and non-humidified (43% RH) glasshouses ventilated with either CO2-enriched or non-enriched air (~1000 vs ~380�μmol mol–1). We monitored effects of elevated humidity and/or CO2 on stomatal conductance, whole-plant transpiration, plant biomass gain, and N accumulation. To facilitate the latter, NO3– enriched in 15N (5 atom%) was added to all pots at the outset of the experiment. Transpiration and 15N accumulation decreased when either CO2 or humidity were elevated. The disparity between N accumulation and accelerated C gain in elevated CO2 led to a 19% decrease in shoot N concentration relative to ambient CO2. Across all treatments, 15N gain was positively correlated with root mass (P<0.0001), and a significant portion of the remaining variation (44%) was positively related to transpiration per unit root mass. At a given humidity, transpiration per unit leaf area was positively related to stomatal conductance. Thus, declines in plant N concentration and/or content under CO2 enrichment may be attributable in part to associated decreases in stomatal conductance and transpiration.

Differential colonization by bioprospected rhizobial bacteria associated with common bean in different cropping systems

2017 ◽  
Vol 63 (8) ◽  
pp. 682-689
Author(s):  
Josiele Polzin de Oliveira-Francesquini ◽  
Mariangela Hungria ◽  
Daiani Cristina Savi ◽  
Chirlei Glienke ◽  
Rodrigo Aluizio ◽  
...  
Keyword(s):  
Common Bean ◽  
Plant Biomass ◽  
Cropping Systems ◽  
Root Nodules ◽  
Housekeeping Genes ◽  
Rrna Gene ◽  
N Fixation ◽  
N Accumulation ◽  
Symbiotic Efficiency ◽  
Plant Nitrogen

In this study, we evaluated the diversity of rhizobia isolated from root nodules on common bean (Phaseolus vulgaris) derived from Andean and Mesoamerican centers and grown under field and greenhouse conditions. Genetic characterization of isolates was performed by sequencing analyses of the 16S rRNA gene and 2 housekeeping genes, recA and glnII, and by the amplification of nifH. Symbiotic efficiency was evaluated by examining nodulation, plant biomass production, and plant nitrogen (N) accumulation. The influence of the environment was observed in nodulation capacity, where Rhizobium miluonense was dominant under greenhouse conditions and the Rhizobium acidisoli group prevailed under field conditions. However, strain LGMB41 fit into a separate group from the type strain of R. acidisoli in terms of multilocus phylogeny, implying that it could belong to a new species. Rhizobium miluonense LGMB73 showed the best symbiotic efficiency performance, i.e., with the highest shoot-N content (77.7 mg/plant), superior to the commercial standard strain (56.9 mg/plant). Biodiversity- and bioprospecting-associated studies are important to better understand ecosystems and to develop more effective strategies to improve plant growth using a N-fixation process.

scholarly journals Why is plant-growth response to elevated CO2 amplified when water is limiting, but reduced when nitrogen is limiting? A growth-optimisation hypothesis

2008 ◽  
Vol 35 (6) ◽  
pp. 521 ◽  
Author(s):  
Ross E. McMurtrie ◽  
Richard J. Norby ◽  
Belinda E. Medlyn ◽  
Roderick C. Dewar ◽  
David A. Pepper ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Elevated Co2 ◽  
Nitrogen Limitation ◽  
Growth Response ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Co2 Enrichment ◽  
Area Index ◽  
Oak Ridge ◽  
Leaf N

Experimental evidence indicates that the stomatal conductance and nitrogen concentration ([N]) of foliage decline under CO2 enrichment, and that the percentage growth response to elevated CO2 is amplified under water limitation, but reduced under nitrogen limitation. We advance simple explanations for these responses based on an optimisation hypothesis applied to a simple model of the annual carbon–nitrogen–water economy of trees growing at a CO2-enrichment experiment at Oak Ridge, Tennessee, USA. The model is shown to have an optimum for leaf [N], stomatal conductance and leaf area index (LAI), where annual plant productivity is maximised. The optimisation is represented in terms of a trade-off between LAI and stomatal conductance, constrained by water supply, and between LAI and leaf [N], constrained by N supply. At elevated CO2 the optimum shifts to reduced stomatal conductance and leaf [N] and enhanced LAI. The model is applied to years with contrasting rainfall and N uptake. The predicted growth response to elevated CO2 is greatest in a dry, high-N year and is reduced in a wet, low-N year. The underlying physiological explanation for this contrast in the effects of water versus nitrogen limitation is that leaf photosynthesis is more sensitive to CO2 concentration ([CO2]) at lower stomatal conductance and is less sensitive to [CO2] at lower leaf [N].

The Influence of CO2 Enrichment on Growth, Nutrient Content and Biomass Allocation of Maranthes corymbosa

1993 ◽  
Vol 41 (2) ◽  
pp. 195 ◽  
Author(s):  
CA Berryman ◽  
D Eamus ◽  
GA Duff
Keyword(s):  
Elevated Co2 ◽  
Plant Biomass ◽  
Nutrient Use Efficiency ◽  
Co2 Enrichment ◽  
Vapour Pressure Deficit ◽  
Density Fluctuations ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Total Plant ◽  
Use Efficiency

Seedlings of Maranthes corymbosa Blume, an evergreen tree of tropical Australia and Indonesia were grown for 32 weeks under conditions of ambient and elevated (700 μmol CO2 mol-1) CO2 in tropical northern Australia. Seedlings were exposed to ambient temperature, vapour pressure deficit and photon flux density fluctuations. Rates of germination and percentage germination were not affected by elevated CO2. Total plant biomass, height growth, total plant leaf area, numbers of leaves and branches and specific leaf weight were significantly increased by elevated CO2. Root:shoot ratio and foliar P, K, Mg, Mn and Ca levels were unaffected but foliar nitrogen levels were decreased by elevated CO2, Nutrient-use-efficiency was unaffected for phosphorus, magnesium, manganese, calcium and potassium but nitrogen-use-efficiency increased in response to elevated CO2.

Effect of elevated CO2 on Vigna radiata and two weed species: yield, physiology and crop–weed interaction

2018 ◽  
Vol 69 (6) ◽  
pp. 617 ◽  
Author(s):  
Jay Prakash Awasthi ◽  
Kamlesh Singh Paraste ◽  
Meenal Rathore ◽  
Mayank Varun ◽  
Disha Jaggi ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Elevated Co2 ◽  
Vigna Radiata ◽  
Co2 Enrichment ◽  
Atmospheric Co2 ◽  
Green Gram ◽  
Weed Species ◽  
Test Species ◽  
Antioxidant Defence System ◽  
Species Specific

A field experiment was conducted in a free-air CO2 enrichment (FACE) facility to investigate the effect of elevated atmospheric CO2 on growth and physiology of green gram (Vigna radiata (L.) R.Wilczek) and associated weed species (Euphorbia geniculata Ortega and Commelina diffusa Burm.f.). Physiological and reproductive behaviour and interaction of the crop and two weed species under elevated CO2 was also studied. Plants were grown under ambient (390 ± 5 ppmv) and elevated (550 ± 50 ppmv) CO2. The results showed that growth, photosynthesis and carbonic anhydrase activity increased in all the test species. Stomatal conductance and transpiration decreased in V. radiata (5.1% and 30.5%, respectively) and C. diffusa (19% and 13.7%) but increased in E. geniculata (6.5% and 27.6%), suggesting a unique adaptive potential of E. geniculata at elevated CO2. Higher accumulation of reactive oxygen species (hydrogen peroxide and superoxide) was noticed at elevated CO2 in V. radiata than in E. geniculata and C. diffusa. Potential of E. geniculata to maintain redox homeostasis in its original state may provide an advantage over two other species in adaptation to climate change. Isoenzyme patterns of superoxide dismutase and stronger activity of antioxidant enzymes suggest species-specific differential regulation and induction of new isoforms under elevated CO2. Enrichment of atmospheric CO2 at a competitive density of weeds lowered the yield (12.12%) and quality of green gram seed, with diminished protein content (16.14% at ambient CO2 to 15.42% at elevated CO2) and enhanced carbohydrate content (3.11%). From the study, it may be concluded that a rise in atmospheric CO2 concentration affects plant performance in a species-specific manner. Among the three species, E. geniculata emerged as most responsive to elevated CO2, showing higher transpiration and stomatal conductance and a stronger antioxidant defence system in a higher CO2 atmosphere. At elevated CO2, weed–crop interaction altered in favour of weeds leading to considerable yield loss of green gram seed.

scholarly journals Effect of water addition and nitrogen fertilization on the fluxes of CH<sub>4</sub>, CO<sub>2</sub>, NO<sub>x</sub>, and N<sub>2</sub>O following five years of elevated CO<sub>2</sub> in the Colorado Shortgrass Steppe

2003 ◽  
Vol 3 (5) ◽  
pp. 1703-1708 ◽  
Author(s):  
A. R. Mosier ◽  
E. Pendall ◽  
J. A. Morgan
Keyword(s):  
Elevated Co2 ◽  
Plant Biomass ◽  
Co2 Enrichment ◽  
Surface Fluxes ◽  
Shortgrass Steppe ◽  
Water Addition ◽  
No Emission ◽  
Ch4 Uptake ◽  
N2o Fluxes ◽  
Ambient Co2

Abstract. An open-top-chamber (OTC) CO2 enrichment (~720 mmol mol-1) study was conducted in the Colorado shortgrass steppe from April 1997 through October 2001. Aboveground plant biomass increased under elevated CO2 and soil moisture content was typically higher than under ambient CO2 conditions. Fluxes of CH4, CO2, NOx and N2O, measured weekly year round were not significantly altered by CO2 enrichment over the 55 month period of observation. During early summer of 2002, following the removal of the open-top-chambers from the CO2 enrichment sites in October 2001, we conducted a short term study to determine if soil microbial processes were altered in soils that had been exposed to double ambient CO2 concentrations during the growing season for the past five years. Microplots were established within each experimental site and 10 mm of water or 10 mm of water containing the equivalent of 10 g m-2 of ammonium nitrate-N was applied to the soil surface. Fluxes of CO2, CH4, NOx and N2O fluxes within control (unchambered), ambient CO2 and elevated CO2 OTC soils were measured at one to three day intervals for the next month. With water addition alone, CO2 and NO emission did not differ between ambient and elevated CO2 soils, while CH4 uptake rates were higher and N2O fluxes lower in elevated CO2 soils. Adding water and mineral N resulted in increased CO2 emissions, increased CH4 uptake and decreased NO emissions in elevated CO2 soils. The N addition study confirmed previous observations that soil respiration is enhanced under elevated CO2 and N immobilization is increased, thereby decreasing NO emission.

Sink Strength May Be the Key to Growth and Nitrogen Responses in N-Deficient Wheat at Elevated CO2

1996 ◽  
Vol 23 (3) ◽  
pp. 253 ◽  
Author(s):  
GS Rogers ◽  
PJ Milham ◽  
M Gillings ◽  
JP Conroy
Keyword(s):  
Elevated Co2 ◽  
Protein Concentration ◽  
Shoot Growth ◽  
Co2 Enrichment ◽  
Sink Strength ◽  
High Co2 ◽  
N Supply ◽  
N Concentration ◽  
Ambient Co2 ◽  
Leaf N

The influence of elevated CO2 (350, 550 and 900 μL L-1) and N supplies ranging from deficient to excess (0-133 mg N kg-1 soil week-1) on the leaf N concentration and shoot growth of wheat (Triticum aestivum L.), cultivar Hartog, was investigated. Shoot growth was 30 % greater at 550 μL L-1 compared to ambient CO2 at all levels of N supply. When the CO2 concentration was increased to 900 μL L-1, there was no increase in shoot growth at low N supply but it more than doubled at high N supply (67 mg N kg-1 soil week-1). Growth effects were closely matched by changes in sink development, suggesting that sink strength, mediated through N supply controlled the shoot growth response to elevated CO2. The shoot N concentration was lower at each level of CO2 enrichment and the greatest effect (30% reduction) occurred at 900 μL CO2 L-1, 33 mg N kg-1 soil week-1. The effect of high CO2 on shoot N concentration diminished as N supply increased and, at the highest N addition rate, there was only a 7% reduction. Changes in foliar N concentration due to CO2 enrichment were closely correlated with lower soluble protein concentration, accounting for 58 % of the total leaf N reduction. Ribulose- IS-bisphosphate carboxylase/oxygenase (Rubisco) levels were also reduced at high CO2 and N was allocated away from Rubisco and into other soluble proteins at high CO2 when N supply was low. Non- structural carbohydrate concentration (dry weight basis) was greatest at 900 μL CO2 L-1 and low N supply and may have reduced Rubisco concentration via a feed-back response. Critical foliar N concentrations (N concentration at 90 % of maximum shoot growth) were reduced from 43 mg g-1 at ambient CO2 to 39 and 38 mg g-1 at 550 and 900 μL CO2 L-1, respectively. Elevated CO2, at N supplies of 0-17 mg N kg-1 soil week-1, reduced flour protein concentration by 9-13 %.

МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ДИНАМИКИ МИНЕРАЛЬНОГО ПИТАНИЯ РАСТЕНИЙ В СИСТЕМЕ «УДОБРЕНИЕ-ПОЧВА-РАСТЕНИЕ»

2020 ◽  
Vol 65 (6) ◽  
pp. 1219-1229
Author(s):  
В.А. Четырбоцкий ◽  
◽  
А.Н. Четырбоцкий ◽  
Б.В. Левин ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Temporal Dynamics ◽  
Plant Biomass ◽  
Environmental Parameters ◽  
Parametric Identification ◽  
Agricultural Crop ◽  
Parameter System ◽  
Plant Nitrogen ◽  
Rhizosphere Microorganisms ◽  
Nitrogen Phosphorus

A numerical simulation of the spatial-temporal dynamics of a multi-parameter system is developed. The components of this system are plant biomass, mobile and stationary forms of mineral nutrition elements, rhizosphere microorganisms and environmental parameters (temperature, humidity, acidity). Parametric identification and verification of the adequacy of the model were carried out based on the experimental data on the growth of spring wheat «Krasnoufimskaya-100» on peat lowland soil. The results are represented by temporal distributions of biomass from agricultural crop under study and the findings on the content of main nutrition elements within the plant (nitrogen, phosphorus, potassium). An agronomic assessment and interpretation of the obtained results are given.

Canopy development and hydraulic function in Eucalyptus tereticornis grown in drought in CO2-enriched atmospheres

2007 ◽  
Vol 34 (12) ◽  
pp. 1137 ◽  
Author(s):  
Brian J. Atwell ◽  
Martin L. Henery ◽  
Gordon S. Rogers ◽  
Saman P. Seneweera ◽  
Marie Treadwell ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Shoot Growth ◽  
Co2 Enrichment ◽  
Atmospheric Co2 ◽  
Shoot Biomass ◽  
Eucalyptus Tereticornis ◽  
Growth Responses ◽  
Ambient Conditions ◽  
Long Distance ◽  
Pipe Model

We report on the relationship between growth, partitioning of shoot biomass and hydraulic development of Eucalyptus tereticornis Sm. grown in glasshouses for six months. Close coordination of stem vascular capacity and shoot architecture is vital for survival of eucalypts, especially as developing trees are increasingly subjected to spasmodic droughts and rising atmospheric CO2 levels. Trees were exposed to constant soil moisture deficits in 45 L pots (30–50% below field capacity), while atmospheric CO2 was raised to 700 μL CO2 L–1 in matched glasshouses using a hierarchical, multi-factorial design. Enrichment with CO2 stimulated shoot growth rates for 12–15 weeks in well-watered trees but after six months of CO2 enrichment, shoot biomasses were not significantly heavier (30% stimulation) in ambient conditions. By contrast, constant drought arrested shoot growth after 20 weeks under ambient conditions, whereas elevated CO2 sustained growth in drought and ultimately doubled the shoot biomass relative to ambient conditions. These growth responses were achieved through an enhancement of lateral branching up to 8-fold due to CO2 enrichment. In spite of larger transpiring canopies, CO2 enrichment also improved the daytime water status of leaves of droughted trees. Stem xylem development was highly regulated, with vessels per unit area and cross sectional area of xylem vessels in stems correlated inversely across all treatments. Furthermore, vessel numbers related to the numbers of leaves on lateral branches, broadly supporting predictions arising from Pipe Model Theory that the area of conducting tissue should correlate with leaf area. Diminished water use of trees in drought coincided with a population of narrower xylem vessels, constraining hydraulic capacity of stems. Commensurate with the positive effects of elevated CO2 on growth, development and leaf water relations of droughted trees, the capacity for long-distance water transport also increased.

Sign in / Sign up

Export Citation Format

Share Document