scholarly journals Carbon Storage Allocation Characteristics of Platycladus Orientalis Plantation Ecosystem with Different Densities

2020 ◽  
Keyword(s):  
Carbon Storage ◽  
Block Design ◽  
Soil Layer ◽  
Stand Density ◽  
Pinus Massoniana ◽  
Organic Carbon Content ◽  
Density Regulation ◽  
Platycladus Orientalis ◽  
Tree Layer

<p>Purpose: To research the influence of different densities of Platycladus orientalis plantation on the allocation characteristics of carbon storage in the ecosystem, the density regulation experiment on the Pinus massoniana plantation with different densities was carried out to discuss the change of the carbon storage of the ecosystem. Method: The density regulation experiment was carried out using random block design along contour line. Through the estimation of tree layer biomass of single Pinus massoniana, the determination of the carbon storage in the tree layer of Pinus massoniana, the estimation of the understory shrub, the grass layer, and the wood layer, the determination of carbon storage in vegetation and litter layer under forest, the determination of organic carbon content and carbon storage in the sample, and the carbon storage of the plantation ecosystem of different stand density sample plots, the effects of stand density on biomass and carbon storage of Pinus massoniana plantation were analyzed. Results: The results of average carbon storage per unit area of Pinus massoniana plantation was different stand densities are 94.11 t/tm2 (1679 plants t/hm2), 79.06 t/tm2 (2250 plants / hm2), 73.32 t/tm2 (2800 plants / hm2). With the increase of stand density, the proportion of carbon storage in Pinus massoniana plantation decreased. This is because the larger the stand density, the more trees with small and medium diameter are grown in the Pinus massoniana plantation. The average diameter at breast height of the stand is very small, and the biomass of single tree decreases. The density is most beneficial to the improvement of the carbon storage of the tree layer. Conclusions: Density regulation promotes the accumulation of carbon storage of the Pinus massoniana plantation and increases the carbon storage of understory vegetation, litter, and soil layer.</p>

scholarly journals Assessment of Carbon Density in Natural Mountain Forest Ecosystems at Northwest China

2021 ◽  
Vol 18 (4) ◽  
pp. 2098
Author(s):  
Li Dai ◽  
Yufang Zhang ◽  
Lei Wang ◽  
Shuanli Zheng ◽  
Wenqiang Xu
Keyword(s):  
Carbon Content ◽  
Carbon Storage ◽  
Forest Ecosystems ◽  
Soil Layer ◽  
Northwest China ◽  
Biomass Carbon ◽  
Forest Age ◽  
Carbon Density ◽  
Old Growth Forest ◽  
Content Ratio

The natural mountain forests in northwest China are recognized as a substantial carbon pool and play an important role in local fragile ecosystems. This study used inventory data and detailed field measurements covering different forest age groups (young, middle-aged, near-mature, mature, old-growth forest), structure of forest (tree, herb, litter and soil layer) and trees (leaves, branches, trunks and root) to estimate biomass, carbon content ratio, carbon density and carbon storage in Altai forest ecosystems. The results showed that the average biomass of the Altai Mountains forest ecosystems was 126.67 t·hm−2, and the descending order of the value was tree layer (120.84 t·hm−2) > herb layer (4.22 t·hm−2) > litter layer (1.61 t·hm−2). Among the tree parts, trunks, roots, leaves and branches accounted for 50%, 22%, 16% and 12% of the total tree biomass, respectively. The average carbon content ratio was 0.49 (range: 0.41–0.52). The average carbon density of forest ecosystems was 205.72 t·hm−2, and the carbon storage of the forest ecosystems was 131.35 Tg (standard deviation: 31.01) inside study area. Soil had the highest carbon storage (65.98%), followed by tree (32.81%), herb (0.78%) and litter (0.43%) layers. Forest age has significant effect on biomass, carbon content ratio, carbon density and carbon storage. The carbon density of forest ecosystems in study area was spatially distributed higher in the south and lower in north, which is influenced by climate, topography, soil types and dominant tree species.

scholarly journals Irrigation Timing as a Practice of Effective Weed Management in Established Alfalfa (Medicago sativa L.) Crop

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 550
Author(s):  
Panagiotis Kanatas ◽  
Ioannis Gazoulis ◽  
Ilias Travlos
Keyword(s):  
Medicago Sativa ◽  
Weed Management ◽  
Cultural Practices ◽  
Block Design ◽  
Chenopodium Album ◽  
Stand Density ◽  
Climatic Conditions ◽  
Amaranthus Retroflexus ◽  
Forage Yield ◽  
Medicago Sativa L

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.

scholarly journals Least limiting water range in Oxisols under different levels of machine traffic

2018 ◽  
Vol 8 (2) ◽  
pp. 337-346
Author(s):  
Karina De Vares Rossetti ◽  
José Frederico Centurion
Keyword(s):  
Bulk Density ◽  
Block Design ◽  
Corn Yield ◽  
Soil Penetration Resistance ◽  
Corn Crop ◽  
Randomized Block Design ◽  
Crop Development ◽  
Least Limiting Water Range ◽  
Different Levels

This work aimed, to evaluate the structural behavior of Oxisols based on the least limiting water range (LLWR) and establish relations with corn crop. The experiment was carried out in a randomized block design with five treatments and four replications. Soil samples collected at the layer of 0-0.20 m depth in a Haplustox (LVd) and an Eutrustox (LVef) were used. The compaction treatments consisted of T0= no additional compaction; T1 and T2= two and four passes with a 4 t tractor, respectively; T3 and T4 = two and four passes with a 10 t tractor, respectively. The range of LLWR variation in the LVd was the lowest one and varied from 0.01 to 0.04 m3 m-3, whereas in the LVef varied from 0.03 to 0.13 m3 m-3 for the critical soil penetration resistance (PRc) of 2 MPa. It was observed that critical bulk density (BDc) values were 1.76 and 1.40 Mg m-3 in the LVd and the LVef, respectively. The highest frequency of bulk density (BC ≥ BDc) occurred from the T1 to T4 (LVd) and from the T2 to T4, however, a reduction in corn yield was not observed. The determination of the LLWR was efficient and complementary for identifying more favorable or more impeditive conditions to compaction in the LVef for the corn crop development in relation to the LVd.

scholarly journals Effects of plant density and proportion on the interaction between wheat with alexandergrass plants

Bragantia ◽  
2011 ◽  
Vol 70 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Leonardo Bianco de Carvalho ◽  
Pedro Luis da Costa Aguiar Alves ◽  
José Valcir Fidelis Martins
Keyword(s):  
Growth And Development ◽  
Plant Density ◽  
Block Design ◽  
Dry Mass ◽  
Wheat Crop ◽  
Replacement Series ◽  
Mixture Experiment ◽  
Randomized Complete Block Design ◽  
Production Characteristics

Determination of competitive relationships among plant species requires appropriate experimental designs and method of analysis. The hypothesis of this research was that two species growing in coexistence show different growth and development due to their relative competitiveness. This research aims to measure the relative competitiveness of wheat crop compared to Alexandergrass by the interpretation of plant density and proportional effects using replacement series experiments. Monocultures were cultivated in densities of 1, 3, 5, 10 and 15 plants per pot and analyzed by regression of dry mass data. Mixture experiment was cultivated in wheat:Alexandergrass proportions of 0:6, 1:5, 2:4, 3:3, 4:2, 5:1 and 6:0 plants per pot and analyzed by graphical interpretation of growth and production characteristics. Both experiments were carried out in randomized complete block design with four replicates. Alexandergrass was more sensitive to intraspecific competition than wheat. Alexandergrass was lightly more competitive than wheat. Number and weight of spikes and number of tillers were the wheat characteristics more affected by Alexandergrass interference.

scholarly journals Analysis of Sentinel 1 Radar Data to Identify Frozing/Thawing Soils in the Area of Anadyr (Chukotka) and Belaya Gora (Yakutia)

2019 ◽  
pp. 29-37
Author(s):  
N. V. Rodionova
Keyword(s):  
Soil Layer ◽  
Texture Features ◽  
Threshold Value ◽  
Radar Data ◽  
Backscatter Coefficient ◽  
Frozen Soils ◽  
Multi Temporal ◽  
Db Difference ◽  
Archive Data

The paper deals with the distinction between thawed and frozen soils in the upper 5 cm layer for two stations in Russia: Belaya Gora (Yakutia) 68.5° N and Anadyr (Chukotka) 64.78° N — by using Sentinel 1 C-band radar data for the period of 2014–2016 years. Determination of the frozen/thawed soil state is carried out in three ways: 1) by multi-temporal radar data on the basis of a significant in 3–5 dB difference in the backscatter coefficient σ0 in the transition of freezing/thawing soil state, 2) by finding the threshold value of σ0 at which the temperature in the upper soil layer falls below 00С, 3) by texture features for one- channel images. The graphs of the AFI (air freezing index) for the period of 2012-2018 with trends are constructed based on the archive data of air temperature for the study areas.

scholarly journals Evaluation of a Simplified Method for GC/MS Qualitative Analysis of Polycyclic Aromatic Hydrocarbons, Polychlorinated Biphenyls, and Organic Pesticides Using PARADISe Computer Program

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3727
Author(s):  
Łukasz Dąbrowski
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Polychlorinated Biphenyls ◽  
Computer Program ◽  
Aromatic Hydrocarbons ◽  
Environmental Samples ◽  
Organic Carbon Content ◽  
Standard Mixture ◽  
Polycyclic Aromatic ◽  
Organic Pesticides

For complex matrices such as environmental samples, there is usually a problem with not fully resolved peaks during GC/MS analysis. The PARADISe computer program (based on the PARFAC2 model) allows the identification of peaks using the deconvoluted mass spectra and the NIST MS library. The number of repetitions required by this software (at least five) is a real limitation for the determination of semi-volatile compounds, like polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organic pesticides in environmental samples. In this work, the method to overcome this condition was proposed and evaluated. The sets of the five files required by PARADISe were prepared by mathematically modifying the original GC/MS chromatograms obtained for the standard mixture (C = 2 µg/mL of 40 compounds) and real sample extracts (soil samples with different total organic carbon content and one cardboard extract) spiked with standards. Total average match factor for all the substances identified in a standard mixture was 874 (near 900—“excellent match”), and for all the substances in the real samples, it was 786 (near 800—“good match”). The results from PARADISe were comparable to those obtained with other programs: AMDIS (NIST) and MassHunter (Agilent), tested also in this work. PARADISe software can be effectively used for chromatogram deconvolution and substance identification.

scholarly journals PSVIII-5 Determination of true digestibility and the endogenous outputs of magnesium in corn for growing pigs by using the regression analysis technique

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 285-285
Author(s):  
Hongzhi Wu ◽  
Xindi Yin ◽  
Zeyu Yang ◽  
Tania Archbold ◽  
Wenyi Fan ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Bone Mineralization ◽  
Block Design ◽  
Growing Pigs ◽  
Linear Relationships ◽  
Diet Formulation ◽  
Analysis Technique ◽  
Dietary Magnesium ◽  
Corn Grain

Abstract Dietary magnesium (Mg) is essential to bone mineralization. Supplemental Mg is typically not considered in commercial swine diets by assuming high bioavailability of Mg from bulky feed ingredients such as corn grain. The objectives of this study were to determine true ileal and fecal digestibility and the endogenous losses of Mg associated with corn in growing pigs by the regression analysis technique. A total of 48 barrows, with an average initial body weight (BW) 32 kg, were randomly assigned to 6 grower pig diets and were fed close to ad libitum for 10 d, with 8-d adaptation and 2-d collection fecal and the terminal ileal digesta samples, according to a randomized complete block design. Six cornstarch-based diets, containing 6 levels of Mg at 0.22, 0.32, 0.38, 0.51, 0.71 and 0.79 g/kg dry matter intake (DMI) of diets, were formulated from corn. There were linear relationships (P &lt; 0.05), expressed as g/kg DMI, between the ileal and fecal outputs of Mg and the total intake of dietary Mg, suggesting that true ileal and fecal Mg indigestibility values (94.8±12.5 vs. 89.2±17.7%); and the ileal and fecal endogenous Mg outputs (0.16±0.02 vs. 0.21±0.11, g/kg DMI of diets) associated with corn could be estimated by the regression analysis. Our results have shown that Mg associated with conventional corn grain was very poorly digested and the gastrointestinal endogenous fecal loss of Mg was significant in the grower pig. Thus, Mg bioavailability in feeds for pigs should be assessed and supplemental of Mg may be warranted in swine diet formulation.

scholarly journals PSVIII-6 The small intestinal responses in the determination of true digestibility and the endogenous outputs of phosphorus in corn for growing pig using the regression analysis technique

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 284-285
Author(s):  
Hongzhi Wu ◽  
Zeyu Yang ◽  
Xindi Yin ◽  
Tania Archbold ◽  
Wenyi Fan ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Block Design ◽  
Growing Pigs ◽  
Gut Permeability ◽  
Feed Conversion ◽  
Linear Relationships ◽  
Analysis Technique ◽  
True Digestibility ◽  
Methodological Considerations

Abstract It is of important methodological considerations to understand how the small intestine would respond to feeding of a series of assay diets deficient in gradient levels of phosphorus (Pi) associated with corn in growing pigs by the regression analysis technique (TRAT). A total of 48 barrows, with an average initial BW 32 kg, were randomly assigned to 6 grower pig diets and were fed close to ad libitum for 10 d, with 8-d adaptation and 2-d collection fecal samples, according to a randomized complete block design. Six cornstarch-based diets, containing 6 levels of Pi at 1.3, 1.9, 2.0, 3.6, 3.4 and 4.0 g/kg DMI, were formulated from corn. The gut permeability marker of D-mannitol was fed 0.30 g/kg BW at 4 h, prior to be sacrificed for sampling. ADG and the apparent ileal DM digestibility were linearly affected (P &lt; 0.05); however, the ADFI, feed conversion ratio, the apparent fecal DM digestibility, transcellular gut permeability and the jejunal alkaline phosphatase kinetics were not affected (P &gt; 0.05) by the increasing dietary levels of corn inclusion. There were linear relationships (P &lt; 0.05), expressed as g/kg DMI, between the apparent ileal and fecal digestible Pi and the total intake of dietary Pi, suggesting that true ileal and fecal Pi digestibility (33.3±4.7 vs. 52.7±3.8%); and the endogenous Pi outputs (0.37±0.12 vs. 0.60±0.09, g/kg DMI) associated with corn could be estimated by the TRAT. Our results have shown that the intestinal physiological functions were not affected in the grower pigs fed on a series of test diets that were deficient in gradient levels of multiple assay nutrients, including macro-minerals, crude protein and amino acids supplied from the testing corn, for a period of 10 d, in the determination of corn-specific true digestibility and the endogenous outputs of Pi by the TRAT.

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