scholarly journals Elevated temperature differently affects growth, photosynthetic capacity, nutrient absorption and leaf ultrastructure of Abies faxoniana and Picea purpurea under intra- and interspecific competition

2019 ◽  
Vol 39 (8) ◽  
pp. 1342-1357 ◽  
Author(s):  
Lei Yu ◽  
Mengya Song ◽  
Zhichao Xia ◽  
Helena Korpelainen ◽  
Ülo Niinemets ◽  
...  
Keyword(s):  
Global Warming ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Interspecific Competition ◽  
Photosynthetic Capacity ◽  
Plant Competition ◽  
Nutrient Absorption ◽  
Dry Matter Accumulation ◽  
Leaf Ultrastructure ◽  
Abies Faxoniana

Abstract There is a limited understanding of the impacts of global warming on intra- and interspecific plant competition. Resolving this knowledge gap is important for predicting the potential influence of global warming on forests, particularly on high-altitude trees, which are more sensitive to warming. In the present study, effects of intra- and interspecific competition on plant growth and associated physiological, structural and chemical traits were investigated in Abies faxoniana and Picea purpurea seedlings under control (ambient temperature) and elevated temperature (ET, 2 °C above ambient temperature) conditions for 2 years. We found that A. faxoniana and P. purpurea grown under intra- and interspecific competition showed significant differences in dry matter accumulation (DMA), photosynthetic capacity, nutrient absorption, non-structural carbohydrate (NSC) contents and leaf ultrastructure under ET conditions. ET increased leaf, stem and root DMA of both conifers under both competition patterns. Moreover, under ET and interspecific competition, P. purpurea had overall superior competitive capacity characterized by higher organ (leaf, stem and root) and total DMA, height growth rate, net photosynthetic rate, specific leaf area, water use efficiency (δ13C), leaf and root N and NSC concentrations and greater plasticity for absorption of different soil N forms. Thus, the growth of P. purpurea benefitted from the presence of A. faxoniana under ET. Our results demonstrated that ET significantly affects the asymmetric competition patterns in subalpine conifer species. Potential alteration of plant competitive interactions by global warming can influence the composition, structure and functioning of subalpine coniferous forests.

Elevated CO2 causes different growth stimulation, water and nitrogen use efficiencies and leaf ultrastructure responses in two conifer species under intra- and interspecific competition

2021 ◽  
Author(s):  
Lei Yu ◽  
Haojie Dong ◽  
Zongdi Huang ◽  
Helena Korpelainen ◽  
Chunyang Li
Keyword(s):  
Plant Growth ◽  
Interspecific Competition ◽  
Elevated Co2 ◽  
Morphological Traits ◽  
Photosynthetic Capacity ◽  
Plant Competition ◽  
Biomass Accumulation ◽  
Leaf Ultrastructure ◽  
Nitrogen Use ◽  
Ectomycorrhizal Infection

Abstract The continuously increasing atmospheric carbon dioxide concentration ([CO2]) has substantial effects on plant growth, and on the composition and structure of forests. However, how plants respond to elevated [CO2] (e[CO2]) under intra- and interspecific competition has been largely overlooked. In this study, we employed Abies faxoniana and Picea purpurea seedlings to explore the effects of e[CO2] (700 ppm) and plant–plant competition on plant growth, physiological and morphological traits, and leaf ultrastructure. We found that e[CO2] stimulated plant growth, photosynthesis and nonstructural carbohydrates (NSC), affected morphological traits and leaf ultrastructure, and enhanced water and nitrogen use efficiencies in A. faxoniana and P. purpurea. Under interspecific competition and e[CO2], P. purpurea showed a higher biomass accumulation, photosynthetic capacity and rate of ectomycorrhizal infection, and higher water and nitrogen use efficiencies compared with A. faxoniana. However, under intraspecific competition and e[CO2], the two conifers showed no differences in biomass accumulation, photosynthetic capacity, and water and nitrogen use efficiencies. In addition, under interspecific competition and e[CO2], A. faxoniana exhibited higher NSC levels in leaves as well as more frequent and greater starch granules, which may indicate carbohydrate limitation. Consequently, we concluded that under interspecific competition, P. purpurea possesses a positive growth and adjustment strategy (e.g., a higher photosynthetic capacity and rate of ectomycorrhizal infection, and higher water and nitrogen use efficiencies), while A. faxoniana likely suffers from carbohydrate limitation to cope with rising [CO2]. Our study highlights that plant–plant competition should be taken into consideration when assessing the impact of rising [CO2] on the plant growth and physiological performance.

scholarly journals Nitrogen Supply Affects Grain Yield by Regulating Antioxidant Enzyme Activity and Photosynthetic Capacity of Maize Plant in the Loess Plateau

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1094
Author(s):  
Kai Yue ◽  
Lingling Li ◽  
Junhong Xie ◽  
Setor Kwami Fudjoe ◽  
Renzhi Zhang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Antioxidant Enzyme ◽  
Loess Plateau ◽  
Photosynthetic Capacity ◽  
Growth And Yield ◽  
Dry Matter Accumulation ◽  
The Loess Plateau ◽  
Area Index ◽  
Leaf Stage ◽  
Significant Difference

Nitrogen (N) is the most limiting nutrient for maize, and appropriate N fertilization can promote maize growth and yield. The effect of N fertilizer rates and timings on morphology, antioxidant enzymes, and grain yield of maize (Zea mays L.) in the Loess Plateau of China was evaluated. The four N levels, i.e., 0 (N0), 100 (N1), 200 (N2), and 300 (N3) kg ha−1, were applied at two timings (T1, one-third N at sowing and two-thirds at the six-leaf stage of maize; T2, one-third applied at sowing, six-leaf stage, and eleven-leaf stage of maize). The results show that N2 and N3 significantly increased the plant height, stem and leaf dry weight, and leaf area index of maize compared with a non-N-fertilized control (N0). The net photosynthetic rate, transpiration rate, stomatal conductance, and leaf chlorophyll contents were lower, while the intercellular carbon dioxide concentration was higher for non-fertilized plants compared to fertilized plants. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased with N rate, but the difference between 200 and 300 kg ha−1 was not significant; further, the isozyme bands of POD and SOD also changed with their activities. Compared with a non-N-fertilized control, N2 and N3 significantly increased grain yield by 2.76- and 3.11-fold in 2018, 2.74- and 2.80-fold in 2019, and 2.71- and 2.89-fold in 2020, and there was no significant difference between N2 and N3. N application timing only affected yield in 2018. In conclusion, 200 kg N ha−1 application increased yield through optimizing the antioxidant enzyme system, increasing photosynthetic capacity, and promoting dry matter accumulation. Further research is necessary to evaluate the response of more cultivars under more seasons to validate the results obtained.

An Open Top Chamber for Forage Maize to Study the Effect of Elevated Temperature by Global Warming

2021 ◽  
Vol 41 (3) ◽  
pp. 183-188
Author(s):  
Chang-Woo Min ◽  
◽  
Inam Khan ◽  
Min-Jun Kim ◽  
Il-Kyu Yoon ◽  
...  
Keyword(s):  
Global Warming ◽  
Elevated Temperature ◽  
Open Top Chamber ◽  
Forage Maize

scholarly journals Thermal Analisys of the Increase in Ambient Temperature Due to Motor Vehicle Activities

2019 ◽  
Vol 9 (2) ◽  
pp. 751-754
Keyword(s):  
Global Warming ◽  
Ambient Temperature ◽  
Motor Vehicle ◽  
The Body ◽  
Motor Vehicles ◽  
Living Things ◽  
Urban Heat ◽  
Specific Material ◽  
Temperature Heating ◽  
Earth Temperature

Global warming has become a problem of world wide, because it endangers living things. The consequences of global warming include the increase of the earth temperature and climate change. The increase of temperature (heating) in a city which is referred to urban heat island (UHI) is also the same problem in architecture. This research aimed to analyze the ambienttemperature of the UHI due to the motor vehicleactivities. Samples were taken from several locations: (1) Bahu Mall Parking area; (2) Manado Town Square 2 parking area; (3) along the Wolter Monginsidi street in front of Bahu Mall and (4) along the Piere Tendean street in front of Manado Town Square. This research used a quantitative method with a field survey. This research found that the ambient temperature increased when motor vehicles were stationary with engine on or moved. The temperature increased due to the heat from the engine and the reflection of the sun’s heat from the body of the vehicles. The heat level obtained from the survey was 34,8 0C to 39,4 0C. For this reason, a specific material for vehicle’s body is needed to prevent the increase of ambient temperature.

Swelling Behavior and Drug Release of Polymer Coated Nano Iron Oxide Embedded Hydroxyapatite

2019 ◽  
Vol 829 ◽  
pp. 108-113
Author(s):  
Yoshiyuki Yokogawa ◽  
Rina Ohkura ◽  
Yoko Inoue ◽  
Atsumasa Shishido ◽  
Ereath Beeran Ansar ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Polyelectrolyte Complex ◽  
Elevated Temperatures ◽  
Release Behavior ◽  
Swelling Properties ◽  
Gel Beads ◽  
Calcium Alginate Gel ◽  
Ca Alginate

Spherical calcium-alginate gel beads containing HAIO, iron oxide (IO) nanoparticles embedded on hydroxapatite (HA), were prepared along with and poly (N-isopropylacrylamide) (PNIPAAM) or chitosan. These spheres, HAIO, HAIO-PNIPAAM and HAIO-chitosan spheres, were used as carriers of 5-fluorouracil (5-FU), one of the drugs for cancer chemical therapy, and the 5-FU release behavior in PBS solution was investigated at ambient and elevated temperatures using U-V spectrometry. The amount of the released 5-FU from the HAIO spheres was somewhat higher than that from HAIO-PNIPAAM and HAIO-chitosan spheres at ambient temperature. At elevated temperature, HAIO spheres showed an increase in quantity of released 5-FU. The amount of released 5-FU from HAIO-PNIPAAM spheres was almost the same, and that from HAIO-chitosan spheres was reduced compared to those at ambient temperature. These spheres, HAIO, HAIO-PNIPAAM and HAIO-chitosan spheres, show the similar swelling properties at elevated temperature. However, the combinations of Ca-alginate - PNIPAAM or Ca-alginate - chitosan may produce the different structures, which are core-shell network for HAIO-PNIPAAM spheres and or a polyelectrolyte complex for HAIO-chitosan spheres, leading to a different release behavior of 5-FU.

scholarly journals Physiological and developmental traits associated with the grain yield of winter wheat as affected by phosphorus fertilizer management

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiu-Xiu Chen ◽  
Wei Zhang ◽  
Xiao-Yuan Liang ◽  
Yu-Min Liu ◽  
Shi-Jie Xu ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Dry Matter ◽  
Photosynthetic Capacity ◽  
Growth Stages ◽  
Photosynthetic Parameters ◽  
Dry Matter Accumulation ◽  
Grain Yields ◽  
P Concentration ◽  
Spike Number

Abstract Although researchers have determined that attaining high grain yields of winter wheat depends on the spike number and the shoot biomass, a quantitative understanding of how phosphorus (P) nutrition affects spike formation, leaf expansion and photosynthesis is still lacking. A 3-year field experiment with wheat with six P application rates (0, 25, 50, 100, 200, and 400 kg P ha−1) was conducted to investigate this issue. Stem development and mortality, photosynthetic parameters, dry matter accumulation, and P concentration in whole shoots and in single tillers were studied at key growth stages for this purpose. The results indicated that spike number contributed the most to grain yield of all the yield components in a high-yielding (>8 t/ha) winter wheat system. The main stem (MS) contributed 79% to the spike number and tiller 1 (T1) contributed 21%. The 2.7 g kg−1 tiller P concentration associated with 15 mg kg−1 soil Olsen-P at anthesis stage led to the maximal rate of productive T1s (64%). The critical shoot P concentration that resulted in an adequate product of Pn and LAI was identified as 2.1 g kg−1. The thresholds of shoot P concentration that led to the maximum productive ability of T1 and optimal canopy photosynthetic capacity at anthesis were very similar. In conclusion, the thresholds of soil available P and shoot P concentration in whole plants and in single organs (individual tillers) were established for optimal spike formation, canopy photosynthetic capacity, and dry matter accumulation. These thresholds could be useful in achieving high grain yields while avoiding excessive P fertilization.

scholarly journals The Nutrient Status of Plant Roots Reveals Competition Intensities in Rubber Agroforestry Systems

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1163
Author(s):  
Junen Wu ◽  
Huanhuan Zeng ◽  
Fan Zhao ◽  
Chunfeng Chen ◽  
Xiaojin Jiang ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Nutrient Concentration ◽  
Plant Competition ◽  
Nutrient Status ◽  
Agroforestry Systems ◽  
Mitigation Strategies ◽  
Plant Roots ◽  
Nutrient Competition ◽  
Plant Leaves ◽  
Competition Intensity

Controversial competition theories may confuse the current understanding of belowground plant competition and thus result in incorrect diagnoses and mitigation strategies for nutrient competition. As such, the management of nutrient competition is a major challenge in the application and development of rubber agroforestry systems (AFSs). To explore the effects of plant competition on the nutrient status of rubber AFSs, this study measured the carbon, nitrogen, and phosphorus concentrations of the litter and soil and in plant leaves, stems, and roots from five rubber plantations (i.e., rubber monocultures and rubber mixed with cocoa, coffee, tea, and Flemingia macrophylla (Willd.) Merr., 1910)). The relative competition intensity indexes were calculated to evaluate the competition intensity of each mixed-species system, and Bayesian networks were established to investigate the linkage effects of interspecific competition for nutrients. This study demonstrated that rubber trees had weak competition with cocoa trees, moderate competition with F. macrophylla and tea trees, and intense competition with coffee trees. With the increase in competition intensity, the negative effects of interspecific competition on soil gradually offset the improvement in soil nutrients achieved with intercropping. Nitrogen and phosphorous translocation from the stems to the roots was enhanced by competition. However, enhanced nutrient allocation to roots may have led to insufficient nitrogen and phosphorous supplies in plant leaves. The quality of the litter therefore decreased because the nutrient status of fallen leaves determines the initial litter conditions. Such consequences may reduce the release of nutrients from the litter to the soil and thus increase soil nutrient depletion. This study revealed that competition effects were most obvious for the root nutrient status, followed by the stem and leaf nutrient statuses. Moreover, this study further demonstrated that the nutrient concentration of plant roots can better indicate the intensity of nutrient competition than the nutrient concentration of other plant organs.

Effect of Sintering Schedule to the Alloyability of FeCrAl Powder Mix Formed at above Ambient Temperature

2015 ◽  
Vol 1115 ◽  
pp. 199-202
Author(s):  
Mujibur M. Rahman ◽  
A.A.A. Talib
Keyword(s):  
Experimental Investigation ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Axial Loading ◽  
Xrd Analysis ◽  
Compaction Process ◽  
Argon Gas ◽  
Fecral Alloy ◽  
Powder Mass ◽  
Die Compaction

This paper presents the outcomes of an experimental investigation on the effect of sintering schedule to the alloyability of FeCrAl powder mix formed through warm powder compaction process. A lab-scale uni-axial die compaction rig was designed and fabricated which enabled the compaction of powder mass at elevated temperature. Iron (Fe) powder ASC 100.29 was mechanically mixed with other alloying elements, namely chromium (Cr), and aluminum (Al) for 60 minutes and compacted at 150°C by applying 130 kN axial loading to generate green compacts. The defect-free green compacts were subsequently sintered in an argon gas fired furnace for different holding times. The sintered samples were then undergone XRD analysis. The results revealed that the alloyability of sintered products were affected by the holding time during sintering. The sample sintered at 800°C for 60 minutes showed the highest intensity of FeCrAl alloy.

scholarly journals Application of the Non-Contact Video Gauge on the Mechanical Properties Test for Steel Cable at Elevated Temperature

2019 ◽  
Vol 9 (8) ◽  
pp. 1670 ◽  
Author(s):  
Yong Du ◽  
Zhang-ming Gou
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Strain Gauge ◽  
Complex Shape ◽  
Full Range ◽  
Steel Cable ◽  
Stress Strain ◽  
Strain Stress ◽  
Steel Cables

As the limit of traditional contact measurement, it is difficult to precisely measure the steel cables twisted by a branch of wires especially at elevated temperature. In this paper the strain-stress relationships of S355 and S690 structural steel, 1860 MPa steel cable twisted by seven wires have been measured by the strain gauge, extensometer and non-contact video gauge at ambient temperature and elevated temperature, respectively. Comparison of the stress-strain curves gotten by different measuring technology, it indicates that the non-contact video gauge can provide a more efficient and reliable database than the strain gauge as well as extensometer, especially at an elevated temperature. It is worth noting that the non-contact video gauge can capture not only the full range of stress-strain curves of steel cables, but is also efficient for the specimens with a complex shape.

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