scholarly journals Impact Analysis of Highway System on Wetland Vegetation in Northern China

2021 ◽  
Author(s):  
Tong Yang ◽  
Cheng Chen ◽  
Xiaoke Wang ◽  
Shilin Xie
Keyword(s):  
Plant Growth ◽  
Plant Community ◽  
Impact Analysis ◽  
Propagation Speed ◽  
Northern China ◽  
Wetland Ecosystems ◽  
Pass Through ◽  
Growth Habits ◽  
Set Up ◽  
Highway System

Wetlands in northern China are complex ecosystems composed of grasslands, lakes, rivers and swamps, which have immense ecological values. When a highway system passes through a wetland, it has adverse effects on its ecosystem. However, in many cases, it is difficult to avoid a highway system pass through a wetland. Taking the Erka wetland in northern China as an example, nine survey lines, perpendicular to the highway, were set up. According to the distance from the highway, the plant multi-element information was collected. After the analysis of plant growth habits, spatial characteristics and profile features, the following four conclusions were drawn: (1) the highway system divided the plants habitat and made the vegetation communities on both sides develop anisotropically; (2) the highway system interfered with the interspecific competition of the nearby plant populations, making it easier for the plant communities with fast propagation speed, drought resistance and anti-interference to establish advantages; (3) the plant growth within 80 m of the highway was inhibited and (4) the wetland plant community succeeded to grassland plant community. In order to reduce the adverse impact of highway system on wetland ecosystems, it is suggested that in the follow-up highway upgrading project, either diversion of highway or construction of bridge or culvert excavation should be considered.

Vibration Analysis of the Continuous Truss Girder Bridge by the Finite Truss Elements

2011 ◽  
Vol 268-270 ◽  
pp. 557-560
Author(s):  
Shi Ruo Yang
Keyword(s):  
Composite System ◽  
Elastic System ◽  
Total Potential Energy ◽  
Time Varying ◽  
Girder Bridges ◽  
Total Potential ◽  
Vibration Responses ◽  
Pass Through ◽  
Girder Bridge ◽  
Set Up

The train and the continuous truss girder bridge are coupled together as one composite system. Truss girder bridge is idealized as an assemblage of finite truss element. The equations of the train and truss girder bridges time varying system are set up by using the principle of total potential energy with stationary value in elastic system dynamics and the“set-in-right-position”rule for forming structural matrices. This method is more convenient than the finite elements. The vibration responses of the train and bridge are calculated when the the passenger trains pass through a continuous truss girder bridge at speeds of 90km/h and 120km/h The results show that the passenger train can pass it safely and comfortably

scholarly journals Understanding Plant Community Responses to Combinations of Biotic and Abiotic Factors in Different Phases of the Plant Growth Cycle

PLoS ONE ◽  
2012 ◽  
Vol 7 (11) ◽  
pp. e49824 ◽  
Author(s):  
Kevin A. Wood ◽  
Richard A. Stillman ◽  
Ralph T. Clarke ◽  
Francis Daunt ◽  
Matthew T. O’Hare
Keyword(s):  
Plant Growth ◽  
Plant Community ◽  
Abiotic Factors ◽  
Growth Cycle ◽  
Community Responses ◽  
Biotic And Abiotic Factors

scholarly journals Utilization of microbial inoculation and compost for revitalization of soils

2009 ◽  
Vol 4 (No. 3) ◽  
pp. 126-130 ◽  
Author(s):  
O. Mikanová ◽  
S. Usťak ◽  
A. Czakó
Keyword(s):  
Plant Growth ◽  
Ammonium Sulphate ◽  
Nitrogenase Activity ◽  
Mineral Fertilizer ◽  
Pot Experiment ◽  
Mineral Fertilizers ◽  
Microbial Inoculation ◽  
Active Population ◽  
Rhizobium Spp ◽  
Set Up

Improving the quality of reclaimed soils requires an active population of microorganisms which can promote plant growth. Increasing the activity of microorganisms can be done by adding nutrients, making agrotechnical soil improvements and by the inoculation of beneficial microorganisms. We investigated the role of fertilizer treatments on plant growth and nitrogen fixation in a pot experiment conducted under green house conditions. Influence of the fertilizer type on numbers of bacteria was also investigated. The seeds were inoculated with the mixture of Azotobacter spp. and Rhizobium spp. The pot experiment was set up with the substrate from the mine spoil (North Bohemia coal basin, the Czech Republic) using Medicago sativa as test plants. The following treatments were used: compost 0, 20, 40, 120, 400, 800 t/ha and mineral fertilizer – ammonium sulphate. The doses of ammonium sulphate were calculated to be equivalent (in nitrogen content) to those doses of compost. Control variants without bacteria inoculation and fertilizers were also included. Inoculation with the mixture of AzotobacterRhizobium spp. significantly increased plant growth and nitrogenase activity. The nitrogenase activity was inhibited by mineral fertilizers in all doses used. The results of the study have proved that compost application stimulated the growth of Azotobacter spp. and Rhizobium spp.

scholarly journals Large-scale predictions of salt-marsh carbon stock based on simple observations of plant community and soil type

2019 ◽  
Vol 16 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Hilary Ford ◽  
Angus Garbutt ◽  
Mollie Duggan-Edwards ◽  
Jordi F. Pagès ◽  
Rachel Harvey ◽  
...  
Keyword(s):  
Plant Community ◽  
Salt Marshes ◽  
Soil Type ◽  
Carbon Stock ◽  
Large Scale ◽  
Coastal Wetland ◽  
Blue Carbon ◽  
Wetland Ecosystems ◽  
Soc Stock ◽  
Carbon Store

Abstract. Carbon stored in coastal wetland ecosystems is of global relevance to climate regulation. Broadscale inventories of this “blue” carbon store are currently lacking and labour intensive. Sampling 23 salt marshes in the United Kingdom, we developed a Saltmarsh Carbon Stock Predictor (SCSP) with the capacity to predict up to 44 % of spatial variation in surface soil organic carbon (SOC) stock (0–10 cm) from simple observations of plant community and soil type. Classification of soils into two types (sandy or not-sandy) explained 32 % of variation in SOC stock. Plant community type (five vegetation classes) explained 37 % of variation. Combined information on soil and plant community types explained 44 % of variation in SOC stock. GIS maps of surface SOC stock were produced for all salt marshes in Wales (∼4000 ha), using existing soil maps and governmental vegetation data and demonstrating the application of the SCSP for large-scale predictions of blue carbon stores and the use of plant community traits for predicting ecosystem services.

How grass contributes to controlling hillslope erosion

2020 ◽  
Author(s):  
Chengzhong Pan ◽  
Lan Ma
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
High Efficiency ◽  
Northern China ◽  
Bare Soil ◽  
Soil Characteristics ◽  
Vegetation Coverage ◽  
Grass Cover ◽  
Run Off ◽  
Set Up

<p>The aim of this study was to investigate how the spatial distribution of grass influenced run-off and erosion from a hillslope with loess and cinnamon soils in the rocky area of Northern China. We set up a trial to test the two soils with different treatments, including bare soil (BS), grass strips on the upper (UGS) and lower (DGS) parts of the slope, grass cover over the entire slope (GS), and a grass carpet on the lower part of the slope (GC), under simulated rainfall conditions. The results showed that the run-off coefficients for the loess and cinnamon soils decreased by between 4% and 20% and by between 2% and 37%, respectively, when covered with grass. Grass spatial distribution had little effect on the run-off, but more effect on erosion than vegetation coverage degree. The most effective location of grass cover for decreasing hillslope erosion was at the foot, and the high efficiency was mainly due to controlling of rill formation and sediment deposition. The soil loss from GS, DGS, and GC on the loess and cinnamon soils was between 77% and 93% less and 55% and 80% less, respectively, compared with the loss from BS. However, the soil characteristics had little effect on soil erosion for well-vegetated slopes. The results highlight the importance of vegetation re-establishment at the foot of hillslope in controlling soil erosion.</p>

Response of the annual biomass production of a typical steppe plant community to precipitation fluctuations

2014 ◽  
Vol 36 (6) ◽  
pp. 527 ◽  
Author(s):  
Zhen Wang ◽  
Qing Zhang ◽  
Xiaoping Xin ◽  
Yong Ding ◽  
Xiangyang Hou ◽  
...  
Keyword(s):  
Plant Community ◽  
Coefficient Of Variation ◽  
Positive Relationship ◽  
Net Primary Production ◽  
Northern China ◽  
Perennial Grasses ◽  
Annual Precipitation ◽  
Typical Steppe ◽  
Grassland Ecosystems ◽  
Annual Biomass

Understanding the relationship between the aboveground net primary production (ANPP) and annual precipitation in arid and semiarid grasslands is crucial for assessing the effects of climate change on grassland ecosystems. The temporal pattern of ANPP, based on long-term data on a semiarid ecosystem in Inner Mongolia, was investigated. The biomass of perennial grasses, perennial forbs and Stipa grandis P. Smirn., showed a positive relationship with annual precipitation. The amount of annual precipitation also changed the annual biomass of 13 other dominant species and consequently the ANPP. The coefficient of variation of the ANPP of the plant community was lower than the coefficient of variation of annual precipitation. Irrespective of the strong inter-annual variation in annual precipitation, the positive relationship found between ANPP and annual precipitation suggests the dependence of ANPP upon hydrological variations in typical steppe. Our findings highlight the importance of dominant perennial species and functional groups in mediating the responses of ANPP to annual precipitation in the typical steppe in northern China.

scholarly journals Modelling and Simulation of Cooperative Control for Bus Rapid Transit Vehicle Platoon in a Connected Vehicle Environment

2017 ◽  
Vol 29 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Jiahui Liu ◽  
Peiqun Lin ◽  
Jing(Peter) Jin
Keyword(s):  
Cooperative Control ◽  
Control Model ◽  
Bus Rapid Transit ◽  
Time Interval ◽  
Connected Vehicle ◽  
Rapid Transit ◽  
Vehicle Platoon ◽  
Connected Vehicle Technology ◽  
Pass Through ◽  
Set Up

The aim of this paper is to develop a cooperative control model for improving the operational efficiency of Bus Rapid Transit (BRT) vehicles. The model takes advantage of the emerging connected vehicle technology. A connected vehicle centre is established to assign a specific reservation time interval and transmit the corresponding dynamic speed guidance to each BRT vehicle. Furthermore, a set of constraints have been set up to avoid bus queuing and waiting phenomena in downstream BRT stations. Therefore, many BRT vehicles are strategically guided to form a platoon, which can pass through an intersection with no impedance. An actual signalized intersection along the Guangzhou BRT corridor is employed to verify and assess the cooperative control model in various traffic conditions. The simulation-based evaluation results demonstrate that the proposed approach can reduce delays, decrease the number of stops, and improve the sustainability of the BRT vehicles.

scholarly journals Effect of Selected Plant Growth Regulators on Yield and Stem Height of Spring Wheat in Ontario

2017 ◽  
Vol 9 (12) ◽  
pp. 30 ◽  
Author(s):  
Yuxue Zhang ◽  
Shengnan Su ◽  
Mirko Tabori ◽  
Junjie Yu ◽  
Denise Chabot ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Spring Wheat ◽  
Active Ingredient ◽  
Growth Yield ◽  
Limiting Factor ◽  
Stem Height ◽  
Stem Strength ◽  
Set Up

Lodging is an important limiting factor in wheat because it affects growth, yield and grain quality. Plant growth regulators (PGRs) are often used to restrain elongation of internodes, improve lodging traits, and protect yield potentials. An experiment was set up in the greenhouse at the Ottawa Research and Development Centre (ORDC) to study the effect of the selected PGRs (Manipulator, the active ingredient of which is chlormequat; and Palisade, the active ingredient of which is trinexapac-ethyl) on yield, stem height and morphological traits in six spring wheat cultivars (AC Carberry, AAC Scotia, Hoffman, Fuzion, FL62R1, and AW725). Both PGRs reduced plant height and caused a 6% to 48% reduction in the length of the second basal internode. The mixture of the two PGRs had a synergistic affect and made the stem shorter. The application of PGRs significantly reduced lodging, increased stem diameter, thickness, filling degree, and stem strength, and increased leaf relative chlorophyll content. However, application of PGRs significantly reduced grain yield, and the combination of the two PGRs (Manipulator and Palisade) had a synergistic effect and lowered the yield. In general, the effect of Palisade was more evident than that of Manipulator.

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