An Energy Budget Approach to the Study of Water Loss in Cryptogams

1970 ◽  
Vol 97 (6) ◽  
pp. 361 ◽  
Author(s):  
George R. Hoffman ◽  
David M. Gates
Keyword(s):  
Energy Budget ◽  
Water Loss

scholarly journals Is Amphistomy an Adaptation to High Light? Optimality Models of Stomatal Traits along Light Gradients

2019 ◽  
Vol 59 (3) ◽  
pp. 571-584 ◽  
Author(s):  
Christopher D Muir
Keyword(s):  
Energy Budget ◽  
Water Loss ◽  
R Package ◽  
High Light ◽  
Carbon Gain ◽  
Marginal Effect ◽  
Costs And Benefits ◽  
Leaf Surfaces ◽  
Stomatal Traits ◽  
Optimality Models

AbstractStomata regulate the supply of CO2 for photosynthesis and the rate of water loss out of the leaf. The presence of stomata on both leaf surfaces, termed amphistomy, increases photosynthetic rate, is common in plants from high light habitats, and rare otherwise. In this study I use optimality models based on leaf energy budget and photosynthetic models to ask why amphistomy is common in high light habitats. I developed an R package leafoptimizer to solve for stomatal traits that optimally balance carbon gain with water loss in a given environment. The model predicts that amphistomy is common in high light because its marginal effect on carbon gain is greater than in the shade, but only if the costs of amphistomy are also lower under high light than in the shade. More generally, covariation between costs and benefits may explain why stomatal and other traits form discrete phenotypic clusters.

scholarly journals Is amphistomy an adaptation to high light? Optimality models of stomatal traits along light gradients

2019 ◽  
Author(s):  
Christopher D. Muir
Keyword(s):  
Energy Budget ◽  
Water Loss ◽  
R Package ◽  
High Light ◽  
Carbon Gain ◽  
Marginal Effect ◽  
Costs And Benefits ◽  
Leaf Surfaces ◽  
Stomatal Traits ◽  
Optimality Models

AbstractStomata regulate the supply of CO2 for photosynthesis and the rate of water loss out of the leaf. The presence of stomata on both leaf surfaces, termed amphistomy, increases photosynthetic rate, is common in plants from high light habitats, and rare otherwise. In this study I use optimality models based on leaf energy budget and photosynthetic models to ask why amphistomy is common in high light habitats. I developed an R package leafoptimizer to solve for stomatal traits that optimally balance carbon gain with water loss in a given environment. The model predicts that amphistomy is common in high light because its marginal effect on carbon gain is greater than in the shade, but only if the costs of amphistomy are also lower under high light than in the shade. More generally, covariation between costs and benefits may explain why stomatal and other traits form discrete phenotypic clusters.

Electron Microscopy of Silicon Deposits in Foliar Idioblasts of Magnolia Grandiflora

1976 ◽  
Vol 34 ◽  
pp. 374-375
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscopy ◽  
Water Loss ◽  
Normal Development ◽  
Magnolia Grandiflora ◽  
Plant Body ◽  
Normal Metabolism ◽  
Hydrated Oxide

Silicon occurs naturally in plants in the form of its hydrated oxide (SiO2.nH2O) commonly called silica. Silica has been shown to be a necessary element in the normal development of many plants, playing an array of roles including strengthening, protection, and reduction of water loss. Deposition of silica in various portions of the plant body, especially the leaves, may also be viewed as a way for the plant to dispose of any excess silica taken up beyond that necessary for normal metabolism.Studies of this “opaline” silica have thus far been limited to species of the Cyperaceae and Gramineae known to possess significant quantities of silica. Within the Magnoliaceae, certain “glistening” idioblast cells at the foliar veinlet termini and vein sheaths of Magnolia grandiflora (1) have been suspected to be siliceous in nature.

The examination of biophysical parameters of skin (transepidermal water loss, skin hydration and pH value) in different body regions of ponies

2012 ◽  
Vol 15 (3) ◽  
pp. 553-559 ◽  
Author(s):  
M.P. Szczepanik ◽  
P.M. Wilkołek ◽  
M. Pluta ◽  
Ł.R. Adamek ◽  
Z.J.H. Pomorski
Keyword(s):  
Water Loss ◽  
Ph Value ◽  
Neck Region ◽  
Transepidermal Water Loss ◽  
Skin Hydration ◽  
Lumbar Region ◽  
Biophysical Parameters ◽  
Body Regions ◽  
Skin Ph

Abstract The purpose of this study was to evaluate transepidermal water loss, skin hydration and skin pH in normal ponies. Sixteen ponies of both sexes were examined in the study. Measurements were taken from seven different sites: the neck region, the shoulder, thorax, lumbar, inguinal, lip region and the auricle. In each of the regions transepidermal water loss (TEWL), skin hydration and skin pH were measured. For transepidermal water loss, the lowest values were observed in the lumbar region (9.71g/hm2), while the highest values were observed in the lip region (22.35 g/hm2). In the case of skin hydration the lowest values were observed for the thorax region (2.13 CU), and the highest for the lip region (41.81 CU). For skin pH, the lowest results were obtained in the lumbar region (6.93), and the highest in the lip region (7.96).

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