Response of phreatophytes to short-term groundwater pumping in a semiarid region: Field experiments and numerical simulations

Ecohydrology ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. e1948 ◽  
Author(s):  
Lihe Yin ◽  
Yangxiao Zhou ◽  
Dandan Xu ◽  
Jun Zhang ◽  
Xiaoyong Wang ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Field Experiments ◽  
Semiarid Region ◽  
Groundwater Pumping ◽  
Short Term

scholarly journals Crop residues on short-term CO2 emissions in sugarcane production areas

2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior
Keyword(s):  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Dry Mass ◽  
Agricultural Crop ◽  
Short Term ◽  
Sugarcane Production ◽  
Soil Temperatures ◽  
Production Areas

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.

scholarly journals Soil carbon release responses to long-term versus short-term climatic warming in an arid ecosystem

2019 ◽  
Author(s):  
Hongying Yu ◽  
Zhenzhu Xu ◽  
Guangsheng Zhou ◽  
Yao Shou
Keyword(s):  
Soil Temperature ◽  
Soil Carbon ◽  
Field Experiments ◽  
Arid Ecosystems ◽  
Organic Carbon Content ◽  
Climatic Warming ◽  
Short Term ◽  
Desert Steppes ◽  
Carbon Release

Abstract. Climate change severely impacts grassland carbon cycling, especially in arid ecosystems, such as desert steppes. However, little is known about the responses of soil respiration (Rs) to different warming magnitudes and watering pulses in situ in desert steppes. To examine their effects on Rs, we conducted long-term moderate warming, short-term acute warming and watering field experiments in a desert grassland of Northern China. While experimental warming significantly reduced Rs by 32.5 % and 40.8 % under long-term and moderate and short-term and acute warming regimes, respectively, watering pulses stimulated it substantially. Warming did not change the exponential relationship between Rs and soil temperature, whereas the relationship of Rs with soil water content (SWC) was well fitted to the Gompertz function. The soil features were not significantly affected by either long-term or short-term warming regimes, respectively; however, soil organic carbon content tended to decrease with long-term climatic warming. This indicates that soil carbon release responses strongly depend on the duration and magnitude of climatic warming, which may be driven by SWC and soil temperature. The results of this study highlight the great dependence of soil carbon emission on warming regimes of different durations and the important role of precipitation pulse during growing season in assessing the terrestrial ecosystem carbon balance and cycle.

scholarly journals The Effect of Binge-Watching on the Subscription of Video on Demand: Results from Randomized Experiments

2020 ◽  
Vol 31 (4) ◽  
pp. 1337-1360
Author(s):  
Miguel Godinho de Matos ◽  
Pedro Ferreira
Keyword(s):  
Field Experiments ◽  
Video On Demand ◽  
Control Group ◽  
Random Set ◽  
Randomized Experiments ◽  
Short Term ◽  
On Demand ◽  
Negative Effect ◽  
Tv Shows ◽  
Supply Costs

We analyze outcomes of two randomized field experiments to study the effect of binge-watching on subscription to video on demand. In both cases, we offered access to subscription video on demand (SVoD) to a random set of households for several weeks and used another random set of households as control group. In both cases, we find that the households induced to binge-watch TV shows are less likely to pay for SVoD after the free trials. Our results suggest that induced binge-watchers deplete the content of interest to them very quickly, which reduces their short-term willingness to pay for SVoD. We also show that carefully crafted recommendation reminders aimed at widening the preferences of consumers for content offset the negative effect of binge-watching and lessen the concerns of binge-watchers with lack of content refresh, and thus these reminders may help content providers manage supply costs, which may otherwise become prohibitive with frequent updates to SVoD catalogs.

Effect of microcracking on the deformation of ice

1992 ◽  
Vol 29 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Ian J. Jordaan ◽  
Barry M. Stone ◽  
Richard F. McKenna ◽  
Mark K. Fuglem
Keyword(s):  
Strain Rate ◽  
Field Experiments ◽  
Constant Strain Rate ◽  
Creep Damage ◽  
Future Research ◽  
Strain Response ◽  
Short Term ◽  
Large Fluctuations ◽  
Response To Stress ◽  
Stress States

Tests in the field and full-scale experience with arctic structures show that the crushing of ice is accompanied by large fluctuations in load. Field experiments show that, in addition to variations of load in time, significant spatial variations across the contact surface also occur. The deformation is observed to take place in a thin layer of damaged ice, which appears near the structure or indenter surface. It is important to model the deformation and strength of ice in this zone. Various aspects of modelling are discussed in the paper, in particular, measures of damage and the relation to the deformation of ice. The relevance of various components of deformation (elastic, viscous, delayed elastic) is outlined, and two mathematical formulations for the deformation are discussed. The behaviour was investigated by a series of tests at constant strain rate as well as tests in which the strain response to stress of damaged and undamaged ice was measured. The creep rate in damaged ice is shown to be significantly enhanced, even for short-term loading. Comparisons of theory and experiment are given for constant strain-rate tests. The models have been calibrated to the experimental data described in the paper. It is a matter for future research to generalize the models to all damage levels and stress states. Key words : creep, damage, deformation, ice, microcracking, visco-elasticity.

scholarly journals Soil carbon release responses to long-term versus short-term climatic warming in an arid ecosystem

2020 ◽  
Vol 17 (3) ◽  
pp. 781-792 ◽  
Author(s):  
Hongying Yu ◽  
Zhenzhu Xu ◽  
Guangsheng Zhou ◽  
Yaohui Shi
Keyword(s):  
Soil Moisture ◽  
Soil Carbon ◽  
Field Experiments ◽  
Sigmoid Function ◽  
Desert Grassland ◽  
Climatic Warming ◽  
Short Term ◽  
Exponential Relationship ◽  
Carbon Release

Abstract. Climate change severely impacts the grassland carbon cycling by altering rates of litter decomposition and soil respiration (Rs), especially in arid areas. However, little is known about the Rs responses to different warming magnitudes and watering pulses in situ in desert steppes. To examine their effects on Rs, we conducted long-term moderate warming (4 years, ∼3 ∘C), short-term acute warming (1 year, ∼4 ∘C) and watering field experiments in a desert grassland of northern China. While experimental warming significantly reduced average Rs by 32.5 % and 40.8 % under long-term moderate and short-term acute warming regimes, respectively, watering pulses (fully irrigating the soil to field capacity) stimulated it substantially. This indicates that climatic warming constrains soil carbon release, which is controlled mainly by decreased soil moisture, consequently influencing soil carbon dynamics. Warming did not change the exponential relationship between Rs and soil temperature, whereas the relationship between Rs and soil moisture was better fitted to a sigmoid function. The belowground biomass, soil nutrition, and microbial biomass were not significantly affected by either long-term or short-term warming regimes, respectively. The results of this study highlight the great dependence of soil carbon emission on warming regimes of different durations and the important role of precipitation pulses during the growing season in assessing the terrestrial ecosystem carbon balance and cycle.

Sign in / Sign up

Export Citation Format

Share Document