SPATIO-TEMPORAL VARIABILITY OF CARBOHYDRATE AND CHLOROPHYLL CONTENT IN THE COFFEE CANOPY

The spatial variability of the total chlorophyll content and carotenoids content, starch and soluble sugars of coffee canopy were mapped throughout the day. Therefore, evaluations were carried out in a ‘Catuaí Vermelho’ coffee plant with 1.7 meters height. A vertical gradient (from the apex to the base of the plant canopy) and a horizontal gradient (plagiotropic branches) were established to analyze different positions of the canopy. Thus, in the vertical direction, four heights were analyzed in the plant: top, upper, middle and lower regions. In the horizontal gradient, the plagiotropic branches were divided into three parts: basal, median and apical. Collection of leaf samples was performed on the east and west sides of the canopy, at 9 a.m., totaling 24 collection points at each time. Higher content of photosynthetic pigments and concentration of sugars were observed in the western face and in the inner parts of the coffee tree. The content of chloroplast pigments and sugars of an individual coffee leaf diverge considerably from other leaves, which requires caution when scaling estimates at the global canopy level. The analysis of some punctual leaves does not serve to discriminate the overall dynamics of a canopy.

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SPATIAL-TEMPORAL PATTERNS OF COFFEE TREE PHYSIOLOGY

Coffee Science ◽

10.25186/cs.v14i3.1574 ◽

2019 ◽

Vol 14 (3) ◽

pp. 291

Author(s):

Paula Tristão Santini ◽

Ronei Aparecido Barbosa ◽

Lorena Gabriela Almeida ◽

Kamila Rezende Dazio De Souza ◽

João Paulo Rodrigues Alves Delfino Barbosa ◽

...

Keyword(s):

Gas Exchange ◽

Coffea Arabica ◽

Vertical Direction ◽

Vertical Gradient ◽

Leaf Temperature ◽

Horizontal Gradient ◽

Plant Canopy ◽

Tree Physiology ◽

Gas Exchange Characteristics ◽

Plagiotropic Branches

The ecophysiological parameters of coffee canopy were mapped throughout the day. Therefore, evaluations were carried out in ‘Catuaí Vermelho’ Coffea arabica L., measuring 1.7 meters. A vertical gradient (from the apex to the base of the plant canopy) and a horizontal gradient (plagiotropic branches) were established to analyze different positions of the canopy. Thus, in the vertical direction, four heights were analyzed in the plant: top, upper, middle and lower regions. In the horizontal gradient, the plagiotropic branches were divided into three parts: basal, median and apical. Collection was performed on the east and west sides of the canopy, at four times of the day: 6 a.m., 9 a.m., noon, and 3 p.m., totaling 24 collection points at each time. Gas exchange, photosynthetically active radiation and leaf temperature were evaluated in each of the 24 points of the coffee canopy. The gas exchange characteristics of an individual coffee leaf diverge considerably from other leaves, which require caution when scaling estimates of leaf photosynthesis at the global canopy level. The analysis of some punctual leaves does not serve to discriminate the overall dynamics of a canopy.

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Contrasted surface mass balances of debris-free glaciers observed between the southern and the inner parts of the Everest region (2007–15)

Journal of Glaciology ◽

10.1017/jog.2017.30 ◽

2017 ◽

Vol 63 (240) ◽

pp. 637-651 ◽

Cited By ~ 25

Author(s):

SONAM FUTI SHERPA ◽

PATRICK WAGNON ◽

FANNY BRUN ◽

ETIENNE BERTHIER ◽

CHRISTIAN VINCENT ◽

...

Keyword(s):

Vertical Gradient ◽

High Elevation ◽

Area Ratio ◽

Horizontal Gradient ◽

Mass Balances ◽

Surface Mass ◽

Maximum Elevation ◽

Accumulation Area Ratio ◽

Inner Parts ◽

Cyclonic Storms

ABSTRACTThree debris-free glaciers with strongly differing annual glaciological glacier-wide mass balances (MBs) are monitored in the Everest region (central Himalaya, Nepal). The mass budget of Mera Glacier (5.1 km2in 2012), located in the southern part of this region, was balanced during 2007–15, whereas Pokalde (0.1 km2in 2011) and West Changri Nup glaciers (0.9 km2in 2013), ~30 km further north, have been losing mass rapidly with annual glacier-wide MBs of −0.69 ± 0.28 m w.e. a−1(2009–15) and −1.24 ± 0.27 m w.e. a−1(2010–15), respectively. An analysis of high-elevation meteorological variables reveals that these glaciers are sensitive to precipitation, and to occasional severe cyclonic storms originating from the Bay of Bengal. We observe a negative horizontal gradient of annual precipitation in south-to-north direction across the range (≤−21 mm km−1, i.e. −2% km−1). This contrasted mass-balance pattern over rather short distances is related (i) to the low maximum elevation of Pokalde and West Changri Nup glaciers, resulting in years where their accumulation area ratio is reduced to zero and (ii) to a steeper vertical gradient of MB for glaciers located in the inner arid part of the range.

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PROSAIL and empirical model to evaluate spatio-temporal heterogeneity of canopy chlorophyll content in subtropical forest

Modeling Earth Systems and Environment ◽

10.1007/s40808-021-01214-4 ◽

2021 ◽

Author(s):

Saurabh Kumar Gupta ◽

Arvind Chandra Pandey

Keyword(s):

Chlorophyll Content ◽

Empirical Model ◽

Subtropical Forest ◽

Temporal Heterogeneity ◽

Spatio Temporal

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Action of ethylene on postharvest of summer squash ‘Menina Brasileira’

Revista CERES ◽

10.1590/0034-737x201764040004 ◽

2017 ◽

Vol 64 (4) ◽

pp. 360-367

Author(s):

Fernanda Ferreira de Araújo ◽

Lucas Cavalcante da Costa ◽

Tania Pires da Silva ◽

Mário Puiatti ◽

Fernando Luiz Finger

Keyword(s):

Weight Loss ◽

Chlorophyll Content ◽

Electrolyte Leakage ◽

Soluble Sugars ◽

Control Treatment ◽

Ethylene Concentration ◽

Malondialdehyde Content ◽

Summer Squash ◽

No Weight Loss ◽

Exogenous Ethylene

ABSTRACT The purpose of this study was to evaluate the sensitivity and the physiological responses of summer squash ‘Menina Brasileira’ to ethylene. Immature fruits were harvested and placed in 20 L sealed buckets, in which ethylene was applied at concentrations of 0.1, 1.0, 10, 100, and 1000 μL L-1 for 24 h. Fruits were placed in buckets with no ethylene as a control treatment. Thereafter, the fruits were taken out of the buckets and maintained on bench, wherein on days 0, 2, 4, 6, and 8, they were evaluated regarding the accumulated fresh weight loss, soluble sugars, reducing and non-reducing sugars, starch, total chlorophyll, content of malondialdehyde, and electrolyte leakage. Fruits of summer squash ‘Menina Brasileira’ showed sensitivity to exogenous ethylene with no weight loss stimulation. Additionally, the fruits exhibited small changes in nutritional quality attributes and changes in the external fruit appearance, including decreased chlorophyll content as well as damage to cell membrane characterized by increase in malondialdehyde content and electrolyte leakage. These changes were stimulated by increasing exogenous ethylene concentration.

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Silicon ameliorates the adverse effects of salt stress on sainfoin (Onobrychis viciaefolia) seedlings

Plant Soil and Environment ◽

10.17221/665/2017-pse ◽

2017 ◽

Vol 63 (No. 12) ◽

pp. 545-551 ◽

Cited By ~ 1

Author(s):

Wu Guo-Qiang ◽

Liu Hai-Long ◽

Feng Rui-Jun ◽

Wang Chun-Mei ◽

Du Yong-Yong

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Adverse Effects ◽

Plant Growth ◽

Membrane Permeability ◽

Chlorophyll Content ◽

Salinity Stress ◽

Soluble Sugars ◽

Organic Solutes ◽

Relative Membrane Permeability

The objective of this study was to investigate whether the application of silicon (Si) ameliorates the detrimental effects of salinity stress on sainfoin (Onobrychis viciaefolia). Three-week-old seedlings were exposed to 0 and 100 mmol/L NaCl with or without 1 mmol/L Si for 7 days. The results showed that salinity stress significantly reduced plant growth, shoot chlorophyll content and root K+ concentration, but increased shoot malondialdehyde (MDA) concentration, relative membrane permeability (RMP) and Na+ concentrations of shoot and root in sainfoin compared to the control (no added Si and NaCl). However, the addition of Si significantly enhanced growth, chlorophyll content of shoot, K+ and soluble sugars accumulation in root, while it reduced shoot MDA concentration, RMP and Na+ accumulation of shoot and root in plants under salt stress. It is clear that silicon ameliorates the adverse effects of salt stress on sainfoin by limiting Na+ uptake and enhancing selectivity for K+, and by adjusting the levels of organic solutes. The present study provides physiological insights into understanding the roles of silicon in salt tolerance in sainfoin.

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Equilibration of Two-Dimensional Double-Diffusive Intrusions

Journal of Physical Oceanography ◽

10.1175/jpo3000.1 ◽

2007 ◽

Vol 37 (3) ◽

pp. 625-643 ◽

Cited By ~ 11

Author(s):

Julian Simeonov ◽

Melvin E. Stern

Keyword(s):

Equilibrium State ◽

Mixed Layer ◽

Vertical Direction ◽

Maximum Velocity ◽

Reynolds Numbers ◽

Horizontal Gradient ◽

Two Dimensional ◽

Salinity Gradients ◽

Gravity Acceleration ◽

Mixed Layers

Abstract This paper considers the equilibration of lateral intrusions in a doubly diffusive fluid with uniform unbounded basic-state gradients in temperature and salinity. These are density compensated in the horizontal direction and finger favorable in the vertical direction. Previous nonlinear studies of this effect have qualitative and quantitative limitations because of their fictitious parameterizations of the weak “turbulence” that arises. Here, two-dimensional direct numerical simulations (DNS) that resolve scales from the smallest to the intrusive are used to predict the equilibrium state. This is achieved by numerically tilting the x–z computational box so that the mean intrusion is represented by a mode with no lateral variation, but smaller-scale 2D eddies comparable to the intrusion thickness are resolved. The DNS show that the initial plane wave intrusion evolves to an equilibrium state containing both a salt finger interface and a diffusive interface, surrounded by well-mixed layers. The inversion of the horizontally averaged density in the mixed layer is negligibly small, but the salt finger buoyancy flux produces large transient density inversions that drive the mixed layer convection. For the considered values of horizontal/vertical gradients, the calculations yield small Cox numbers and buoyancy Reynolds numbers [comparable to those measured in staircases during the Caribbean-Sheets and Layers Transects (C-SALT) program]. An important testable result is the time-averaged maximum velocity of the fastest-growing intrusion Umax = 18.0 (Σ*z/Σ*x)+1/2KT(gΘ*z/νKT)1/4. Here Θ*z is the undisturbed vertical temperature gradient in buoyancy units, Σ*z and Σ*x are the corresponding vertical and horizontal salinity gradients, g is the gravity acceleration, and ν and KT are the respective values of the molecular viscosity and heat diffusivity. The paradoxical inverse dependence on the horizontal gradient results from the assumption that the latter is unbounded.

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Microgravimetric and gravity gradient techniques for detection of subsurface cavities

Geophysics ◽

10.1190/1.1441723 ◽

1984 ◽

Vol 49 (7) ◽

pp. 1084-1096 ◽

Cited By ~ 151

Author(s):

Dwain K. Butler

Keyword(s):

Case History ◽

Vertical Gradient ◽

Gravity Gradient ◽

Horizontal Gradient ◽

Shallow Subsurface ◽

Gradient Profile ◽

First Case ◽

Profile Line ◽

Cavity System ◽

Subsurface Cavities

Microgravimetric and gravity gradient surveying techniques are applicable to the detection and delineation of shallow subsurface cavities and tunnels. Two case histories of the use of these techniques to site investigations in karst regions are presented. In the first case history, the delineation of a shallow (∼10 m deep), air‐filled cavity system by a microgravimetric survey is demonstrated. Also, application of familiar ring and center point techniques produces derivative maps which demonstrate (1) the use of second derivative techniques to produce a “residual” gravity map, and (2) the ability of first derivative techniques to resolve closely spaced or complex subsurface features. In the second case history, a deeper (∼ 30 m deep), water‐filled cavity system is adequately detected by a microgravity survey. Results of an interval (tower) vertical gradient survey along a profile line are presented in the second case history; this vertical gradient survey successfully detected shallow (<6 m) anomalous features such as limestone pinnacles and clay pockets, but the data are too “noisy” to permit detection of the vertical gradient anomaly caused by the cavity system. Interval horizontal gradients were determined along the same profile line at the second site, and a vertical gradient profile is determined from the horizontal gradient profile by a Hilbert transform technique. The measured horizontal gradient profile and the computed vertical gradient profile compare quite well with corresponding profiles calculated for a two‐dimensional model of the cavity system.

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Generalized gravity gradient analysis for 2-D inversion

Geophysics ◽

10.1190/1.1443830 ◽

1995 ◽

Vol 60 (4) ◽

pp. 1018-1028 ◽

Cited By ~ 15

Author(s):

Dwain K. Butler

Keyword(s):

Gravity Data ◽

Vertical Gradient ◽

Diagnostic Information ◽

Effective Density ◽

Gravity Gradient ◽

Horizontal Gradient ◽

Plate Model ◽

Structural Interpretation ◽

Gradient Profile ◽

Inversion Procedure

Gravity gradient profiles across subsurface structures that are approximately 2-D contain diagnostic information regarding depth, size, and structure (geometry). Gradient space plots, i.e., plots of horizontal gradient versus vertical gradient, present the complete magnitude and phase information in the gradient profiles simultaneously. Considerable previous work demonstrates the possibility for complete structural interpretation of a truncated plate model from the gradient space plot. The qualitative and quantitative diagnostic information contained in gradient space plots is general, however. Examination of the characteristics of gradient space plots reveals that 2-D structures are readily classified as extended or localized. For example, the truncated plate model is an extended model, while the faulted plate model is a localized model. Comparison of measured or calculated gradient space plots to a model gradient space plot catalog allows a rapid, qualitative determination of structure or geometry. “Corners” of a polygonal cross‐section model are then determined as profile points corresponding to maxima on the vertical gradient profile. A generalized approach to structural interpretation from gravity data consists of (1) determining vertical and horizontal gradient profiles perpendicular to the strike of a 2-D gravity anomaly, (2) determining the structural geometry from the gradient space plot, and (3) locating profile positions of structural corners from the vertical gradient profile. This generalized inversion procedure requires no quantitative information or assumption regarding density contrasts. Iterative forward modeling then predicts the density contrasts. Application of this generalized gravity gradient inversion procedure to high quality gravity data results in an effective density prediction consistent with measured near‐surface densities and the known increase in density with depth in deep sedimentary basins.

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Relationships between regional ventilation and vascular and extravascular volume in supine humans

Journal of Applied Physiology ◽

10.1152/jappl.1994.76.3.1195 ◽

1994 ◽

Vol 76 (3) ◽

pp. 1195-1204 ◽

Cited By ~ 24

Author(s):

L. H. Brudin ◽

C. G. Rhodes ◽

S. O. Valind ◽

T. Jones ◽

B. Jonson ◽

...

Keyword(s):

Left Lung ◽

Vertical Direction ◽

Vertical Gradient ◽

Quiet Breathing ◽

Alveolar Volume ◽

Positron Emission ◽

Significant Linear Correlation ◽

Horizontal Variation ◽

Gravitational Gradients ◽

Extravascular Volume

With the use of positron emission tomography, alveolar ventilation (VA), lung density, and pulmonary blood volume (VB) were measured regionally in eight nonsmokers in the supine posture and one nonsmoker in the prone posture during quiet breathing in a transaxial thoracic section at midheart level. Regional values of alveolar volume (VA) and extravascular tissue volume (VEV) were derived from the inherent relationships between different compartments in the lung. Ratios proportional to gas volume (VA/VEV) and ventilation (VA/VEV) per alveolar unit, respectively, were calculated. No differences between right and left lung were found. Variations in the vertical direction could explain approximately 65% of the total within-group variation in VA, VB, and ln (VA), whereas the corresponding value for horizontal variation was only 3–9% (right lung, supine subjects). Similar gravitational gradients were found in the single prone subject. There was a significant linear correlation between VA and ln (VA). When VA and VA are related to a given number of alveolar units (VEV), the data are consistent with a linear relationship between VA/VEV and VA/VEV, indicating that ventilation might be explained by the elastic properties of lung tissue according to Salazar and Knowles (J. Appl. Physiol. 19: 97–104, 1964). Regional VB was closely associated with the gradient of regional alveolar volume (VA/VEV) (by virtue of weight of blood and competition for space) and therefore, indirectly, closely associated with the vertical gradient of ventilation.

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