scholarly journals Litter Quality Affects Termite Sheeting Production and Water Infiltration in the Soil

Sociobiology ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 491 ◽  
Author(s):  
Rashmi R Shanbhag ◽  
Ajay Harit ◽  
Sougueh Cheik ◽  
Ekta Chaudhary ◽  
Nicolas Bottinelli ◽  
...  
Keyword(s):  
Steady State ◽  
Deciduous Forest ◽  
Food Preferences ◽  
Soil Surface ◽  
Water Infiltration ◽  
Infiltration Rates ◽  
Significant Difference ◽  
Consumption Rates ◽  
Odontotermes Obesus ◽  
Elephant Dung

This study aimed to understand the relationship between termite food preferences and the ecological benefits derived from their activity in terms of soil dynamics and water infiltration. A field study was carried out for six months with different food baits (elephant dung, Acacia leaves, twigs and leaves of Lantana camara as well as Ficus religiosa, Pterocarpus marsupium, Prosopis juliflora, Michelia champaca, Azadirachta indica and Hevea brasiliensis wood stakes) installed on the soil surface in a semi-deciduous forest in southern India. At the end of the experiment we determined bait consumption rates and the amount of soil sheetings covering the different baits. Water infiltration rates were also measured using the Beerkan method. The initial infiltration rates (i.e. average of the first three infiltration rates) under the baits were compared to those at the end of the experiment (average of the last three infiltration rates when the steady state was reached). Three termite species, Odontotermes obesus, O. feae and Microtermes obesi, were found associated with some of the baits in the study area. Among the different baits, elephant dung and Acacia leaves were the most preferred and a relationship was observed between the quantity of soil sheetings and the bait consumption rate. Termite preference for elephant dung and Acacia leaves was also associated with higher water infiltration rates. However, this difference was only significant at the beginning of the experiment and no significant difference was measured once the steady state was reached. In conclusion, we showed that resource quality was of primary importance for soil sheeting production but that the influence of termites on water infiltration remained limited, most likely because of the low stability of their tunnels in the soil.

scholarly journals Linking Termite Feeding Preferences and Soil Physical Functioning in Southern-Indian Woodlands

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 4 ◽  
Author(s):  
Sougueh Cheik ◽  
Rashmi Ramesh Shanbhag ◽  
Ajay Harit ◽  
Nicolas Bottinelli ◽  
Raman Sukumar ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Deciduous Forest ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
Water Infiltration ◽  
Arid Environments ◽  
Feeding Preferences ◽  
Soil Hydraulic Conductivity ◽  
Odontotermes Obesus ◽  
Soil Hydraulic

Termites are undoubtedly amongst the most important soil macroinvertebrate decomposers in semi-arid environments in India. However, in this specific type of environment, the influence of termite foraging activity on soil functioning remains unexplored. Therefore, this study examines the link between the quality of litter and the functional impact of termite feeding preferences on soil properties and soil hydraulic conductivity in a deciduous forest in southern India. Different organic resources (elephant dung: “ED”, elephant grass: “EG”, acacia leaves: “AL” and layers of cardboard: “CB”) were applied on repacked soil cores. ED appeared to be the most attractive resource to Odontotermes obesus, leading to a larger amount of soil sheeting (i.e., the soil used by termites for covering the litter they consume), more numerous and larger holes in the ground and a lower soil bulk density. As a consequence, ED increased the soil hydraulic conductivity (4-fold) compared with the control soil. Thus, this study highlights that the more O. obesus prefers a substrate, the more this species impacts soil dynamics and water infiltration in the soil. This study also shows that ED can be used as an efficient substrate for accelerating the infiltration of water in southern-Indian soils, mainly through the production of galleries that are open on the soil surface, offering new perspectives on termite management in this environment.

Assessing the influence of shrubs and their interspaces on enhancing infiltration in an arid Australian shrubland.

2000 ◽  
Vol 22 (1) ◽  
pp. 58 ◽  
Author(s):  
DL Dunkerley
Keyword(s):  
Soil Surface ◽  
Local Environment ◽  
Test Site ◽  
Water Infiltration ◽  
Soil Protection ◽  
Plant Canopy ◽  
Two Phase ◽  
Infiltration Rates ◽  
Zone Of Influence ◽  
Rangeland Condition

In assessments of rangeland condition, the fraction of the soil surface lying beneath the canopy of a plant has been widely adopted as a measure of soil protection afforded by the plant, and of the size of the area of altered micro-environment associated with it. In this local environment, various factors produce more permeable soils that allow faster uptake of rainwater than occurs through soils in the open interspaces between plants, or in degraded rangeland where plant canopy cover has been diminished. However, the nature and location of the transition from 'shrub' to 'interspace' hydrologic behaviour has remained illdefined, and the appropriateness of this two-phase subdivision of shrublands remains to be established. This paper reports on a study designed to begin this process by assessing the size of the 'zone of influence' exerted by bluebush shrubs (Maireana spp.) on water infiltration rates in their vicinity, using a test site at Fowlers Gap, north of Broken Hill, NSW. Using radial transects of infiltrometer data extending from close to the stem into the open interspace, it is shown that infiltration rates do not change abruptly at the canopy margin. Rather, enhanced water uptake persists for some distance into the interspace. According to present results, the plant canopy only covers the central one-third of this larger zone of influence, and so provides an inadequate measure of it. Measures of the persistence in time and lateral extent of the zone of influence may provide more meaningful and more sensitive measures of rangeland condition in the arid and semi-arid shrublands.

scholarly journals Soil water dynamics related to the degree of compaction of two brazilian oxisols under no-tillage

2009 ◽  
Vol 33 (5) ◽  
pp. 1097-1104 ◽  
Author(s):  
Vanderlei Rodrigues da Silva ◽  
José Miguel Reichert ◽  
Dalvan José Reinert ◽  
Edson Campanhola Bortoluzzi
Keyword(s):  
Steady State ◽  
Hydraulic Conductivity ◽  
Soil Water ◽  
Infiltration Rate ◽  
Saturated Soil ◽  
Water Dynamics ◽  
Water Infiltration ◽  
No Tillage ◽  
Significant Difference ◽  
Compaction Degree

Soil water properties are related to crop growth and environmental aspects and are influenced by the degree of soil compaction. The objective of this study was to determine the water infiltration and hydraulic conductivity of saturated soil under field conditions in terms of the compaction degree of two Oxisols under a no-tillage (NT). Two commercial fields were studied in the state of Rio Grande do Sul, Brazil: one a Haplortox after 14 years under NT; the other a Hapludox after seven years under NT. Maps (50 x 30 m) of the levels of mechanical penetration resistance (PR) were drawn based on the kriging method, differentiating three compaction degrees (CD): high, intermediate and low. In each CD area, the infiltration rate (initial and steady-state) and cumulative water infiltration were measured using concentric rings, with six replications, and the saturated hydraulic conductivity (K(θs)) was determined using the Guelph permeameter. Statistical evaluation was performed based on a randomized design, using the least significant difference (LSD) test and regression analysis. The steady-state infiltration rate was not influenced by the compaction degree, with mean values of 3 and 0.39 cm h-1 in the Haplortox and the Hapludox, respectively. In the Haplortox, saturated soil hydraulic conductivity was 26.76 cm h-1 at a low CD and 9.18 cm h-1 at a high CD, whereas in the Hapludox, this value was 5.16 cm h-1 and 1.19 cm h-1 for the low and high CD, respectively. The compaction degree did not affect the initial and steady-state water infiltration rate, nor the cumulative water infiltration for either soil type, although the values were higher for the Haplortox than the Hapludox.

The influence of glaciations on the dynamics of mountain hydrothermal systems: numerical modeling of the La Léchère system (Savoie, France)

2010 ◽  
Vol 181 (4) ◽  
pp. 295-304 ◽  
Author(s):  
Emilie Thiebaud ◽  
Stéphanie Gallino ◽  
Marc Dzikowski ◽  
Dominique Gasquet
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Thermal Anomaly ◽  
Hydrothermal Systems ◽  
Water Infiltration ◽  
Thermal Waters ◽  
Glacial Period ◽  
Infiltration Rates ◽  
Alpine Valleys ◽  
Current Heat

Abstract Although thermal waters are found in numerous Alpine valleys, the mechanisms responsible for their occurrence remain unclear. The present study used a 2-D numerical model of an Alpine hydrothermal system (La Léchère, Savoie) to investigate these mechanisms. A steady-state hydrodynamic model was calibrated using present-day observations, and then applied to predict outlet temperatures assuming steady-state conditions and the current heat flux and water flow. This simulation produced anomalously low outlet temperatures compared with present-day temperatures, indicating that water circulation within the La Léchère aquifer cannot have been constant throughout its history. Based on the suggestion that glaciations block aquifer circulation, a second simulation was carried out assuming zero water infiltration during the Würm glacial period. The outlet temperatures predicted by this second simulation were much closer to present-day temperatures. These two simulations show that the thermal anomaly at La Léchère is incompatible with the classic model of the progressive heating of thermal waters and that the current temperature of the thermal waters can be explained by changes in aquifer infiltration rates.

scholarly journals INFILTRAÇÃO DE ÁGUA EM UM LATOSSOLO ROXO MUITO ARGILOSO EM DOIS SISTEMAS DE MANEJO

Irriga ◽  
2002 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Mario Artemio Urchei ◽  
Carlos Ricardo Fietz
Keyword(s):  
Cropping Systems ◽  
Soil Surface ◽  
Infiltration Rate ◽  
Conventional Tillage ◽  
Water Infiltration ◽  
No Tillage ◽  
Mato Grosso ◽  
Double Ring ◽  
Infiltration Rates ◽  
Infiltration Tests

INFILTRAÇÃO DE ÁGUA EM UM LATOSSOLO ROXO MUITO ARGILOSO EM DOIS SISTEMAS DE MANEJO   Mário Artemio UrcheiCarlos Ricardo FietzEmbrapa Agropecuária Oeste, Caixa Postal 661, 79804-970 – Dourados, MSE-mail: [email protected] e [email protected]   1 RESUMO              Este trabalho objetivou caracterizar a infiltração de água em um latossolo roxo muito argiloso em dois sistemas de manejo (preparo convencional - PC e plantio direto - PD) e avaliar a adequação das equações de Horton e Kostiakov-Lewis para a estimativa da taxa de infiltração básica. O trabalho foi desenvolvido na área experimental da Embrapa Agropecuária Oeste, em Dourados, MS, durante os anos de 1994 e 1995. Em cada um dos sistemas foram realizados 25 testes de infiltração pelo método do infiltrômetro de duplo cilindro. Considerou-se como taxa de infiltração básica observada a média aritmética dos valores lidos após 120 minutos, enquanto sua estimativa foi feita pelas equações de Horton e de Kostiakov-Lewis. A taxa de infiltração básica, nos dois sistemas de manejo, ajustou-se à distribuição normal, de acordo com o teste de Kolmogorov-Smirnov, sem diferença entre as médias de 92,2 e 92,8mm h-1 (Tukey, 5%), para os sistemas PC e PD, respectivamente, consideradas muito altas. Esses valores apresentaram alta variabilidade nos dois sistemas, com coeficientes de variação de 78,6% para o PC e 83,5% para o PD. Apesar de as duas equações terem apresentado bom ajuste, os índices estatísticos evidenciaram que a equação de Kostiakov-Lewis é mais adequada para estimar a taxa de infiltração básica no latossolo roxo estudado.   UNITERMOS: Equações de infiltração, plantio direto, preparo convencional.   URCHEI, M. A.,  FIETZ, C.R.  WATER INFILTRATION IN AN OXISOL UNDER TWO CROPPING SYSTEMS   2 ABSTRACT   This work aimed to characterize water infiltration and evaluate the adequacy of Horton and Kostiachov-Lewis’s equations to estimate basic infiltration rate in an Oxisol under conventional tillage (CT) and no tillage (NT). The work was carried out over 1994 and 1995 in an experimental area of Embrapa Agropecuaria Oeste in Dourados city, Mato Grosso do Sul State, Brazil. For each  system  25  infiltration  tests  were  performed  by  the  double  ring infiltrometer method. Basic infiltration rates were  the average  of  infiltration measured  after  120 min of adding water on the soil surface. Estimation of basic infiltration rates has been performed by using Horton and Kostiakov-Lewis’s equations. Basic infiltration rates in both systems followed normal distribution according to Kolmogorov-Smirnov’s test. Average values for basic infiltration were 92.2 and 92.8 mm h-1 for CT and NT systems, respectively. No significantly different means have been observed  (P<0.05). The variation coefficients were 78.6% for CT and 83.5% for NT. In spite of two equations good adequacy, statistical indexes showed that Kostiakov-Lewis’s equation has been more fitted to estimate basic infiltration rates for the  studied Oxisol.  KEYWORDS: Infiltration equations, no tillage, conventional tillage.

Effect of Chemical and Tillage Summer Fallow upon Water‐Infiltration Rates

1955 ◽  
Vol 47 (5) ◽  
pp. 235-236 ◽  
Author(s):  
O. K. Barnes ◽  
D. W. Bohmont ◽  
Frank Rauzi
Keyword(s):  
Water Infiltration ◽  
Infiltration Rates ◽  
Summer Fallow

Association of CYP2D6*10 (c. 100 C>T) Genotype with Z-END Concentration in Patients with Breast Cancer Receiving Tamoxifen Therapy in Indonesian Population

2019 ◽  
Vol 19 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Yenny ◽  
Sonar S. Panigoro ◽  
Denni J. Purwanto ◽  
Adi Hidayat ◽  
Melva Louisa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Ultra Performance Liquid Chromatography ◽  
Cross Sectional Study ◽  
Threshold Concentration ◽  
Breast Cancer Patients ◽  
Cross Sectional ◽  
Significant Difference ◽  
Pcr Rflp ◽  
Liquid Chromatography Tandem Mass

Background: Tamoxifen (TAM) is a frequently used hormonal prodrug for patients with breast cancer that needs to be activated by cytochrome P450 2D6 (CYP2D6) into Zusammen-endoxifen (Z-END). Objective: The purpose of the study was to determine the association between CYP2D6*10 (c.100C>T) genotype and attainment of the plasma steady-state Z-END minimal threshold concentration (MTC) in Indonesian women with breast cancer. Methods: A cross-sectional study was performed in 125 ambulatory patients with breast cancer consuming TAM at 20 mg/day for at least 4 months. The frequency distribution of CYP2D6*10 (c.100C>T) genotypes (C/C: wild type; C/T: heterozygous mutant; T/T: homozygous mutant) was detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), the results of which were subsequently confirmed by sequencing. The genotypes were categorized into plasma Z- END concentrations of <5.9 ng/mL and ≥5.9 ng/mL, which were measured using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Results: Percentages of C/C, CT, and T/T genotypes were 22.4%, 29.6%, and 48.8%, respectively. Median (25-75%) Z-END concentrations in C/C, C/T, and T/T genotypes were 9.58 (0.7-6.0), 9.86 (0.7-26.6), and 3.76 (0.9-26.6) ng/mL, respectively. Statistical analysis showed a significant difference in median Z-END concentration between patients with T/T genotype and those with C/C or C/T genotypes (p<0.001). There was a significant association between CYP2D6*10 (c.100C>T) genotypes and attainment of plasma steady-state Z-END MTC (p<0.001). Conclusion: There was a significant association between CYP2D6*10 (c.100C>T) and attainment of plasma steady-state Z-END MTC in Indonesian breast cancer patients receiving TAM at a dose of 20 mg/day.

scholarly journals Modeling and Optimizing the Multi-Objective Portfolio Optimization Problem with Trapezoidal Fuzzy Parameters

2021 ◽  
Vol 26 (2) ◽  
pp. 36
Author(s):  
Alejandro Estrada-Padilla ◽  
Daniela Lopez-Garcia ◽  
Claudia Gómez-Santillán ◽  
Héctor Joaquín Fraire-Huacuja ◽  
Laura Cruz-Reyes ◽  
...  
Keyword(s):  
Steady State ◽  
Portfolio Optimization ◽  
Optimization Problem ◽  
Solution Process ◽  
Density Estimator ◽  
Nsga Ii ◽  
Spatial Spread ◽  
Multi Objective ◽  
Significant Difference ◽  
Portfolio Optimization Problem

A common issue in the Multi-Objective Portfolio Optimization Problem (MOPOP) is the presence of uncertainty that affects individual decisions, e.g., variations on resources or benefits of projects. Fuzzy numbers are successful in dealing with imprecise numerical quantities, and they found numerous applications in optimization. However, so far, they have not been used to tackle uncertainty in MOPOP. Hence, this work proposes to tackle MOPOP’s uncertainty with a new optimization model based on fuzzy trapezoidal parameters. Additionally, it proposes three novel steady-state algorithms as the model’s solution process. One approach integrates the Fuzzy Adaptive Multi-objective Evolutionary (FAME) methodology; the other two apply the Non-Dominated Genetic Algorithm (NSGA-II) methodology. One steady-state algorithm uses the Spatial Spread Deviation as a density estimator to improve the Pareto fronts’ distribution. This research work’s final contribution is developing a new defuzzification mapping that allows measuring algorithms’ performance using widely known metrics. The results show a significant difference in performance favoring the proposed steady-state algorithm based on the FAME methodology.

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