Immigration Reforms Could Stem Flow Of Noncitizen Chemical Scientists

1996 ◽  
Vol 74 (11) ◽  
pp. 26-28
Author(s):  
LINDA ROSS RABER
1995 ◽  
Vol 75 (1) ◽  
pp. 99-103 ◽  
Author(s):  
C. S. Tan ◽  
B. R. Buttery

Using heat-balance stem flow gauges, we were able to measure directly and continuously the sap flow rates in two pairs of soybean [Glycine max (L.) Merr.] isolines differing in stomatal frequency. Plants with high stomatal frequency transpired significantly more water than the low stomatal frequency plants at high soil moisture levels. Under low soil moisture levels, the water use rate decreased greatly for the high stomatal frequency plants. Plants with low stomatal frequency were able to maintain greater sap flow rates than those with high stomatal frequency. Higher leaf temperatures associated with the low stomatal frequency plants were likely due to lower transpiration rates which reduced evaporative cooling especially under well-watered conditions. Key words:Glycine max (L.) Merr., transpiration, water deficits


1998 ◽  
Vol 4 (1) ◽  
pp. 11-15
Author(s):  
Zenfuku Koki ◽  
Yuei Nakama ◽  
Eiji Nakada ◽  
Tsugio Ezaki
Keyword(s):  

Author(s):  
Wanjing Li ◽  
Li Zhao ◽  
Guang Yang ◽  
Ke Yan ◽  
Xinlin He ◽  
...  

Abstract Analysis of water source and moisture transfer characteristics of desert plants is of great significance for ecological restoration in arid areas. In this study, the water source utilized by the desert plant, Haloxylon ammodendron, was analysed using the stable isotope technique, and the water transportation characteristics were obtained based on the proportional heat balance method under different weather conditions. The results showed that (1) before raining, the moisture of H. ammodendron mainly relied on groundwater (the average contribution rate was 34.14%) and on soil water located at a depth of 120–180 cm (the average contribution rate was 29.87%). After the rain, H. ammodendron mainly absorbed soil water from a depth of 60–120 cm (the average contribution rate was 33.19%) and groundwater (the average contribution rate was 30.67%); (2) the stem flow of H. ammodendron showed an obvious diurnal variation, showing a “midday rest” phenomenon. The stem flow showed a peak value, and in sunny days, it was ~2 fold higher than that in cloudy days. (3) The stem flow rate of H. ammodendron varied regularly overtime as follows: August > July > September > June > May, and the meteorological factors affecting its stem flow were solar radiation (0.826) > atmospheric temperature (0.598) > humidity (-0.573). The results provide basic support for the ecological conservation of the desert plant H. ammodendron, while also having important implications for ecological restoration in arid regions.


2004 ◽  
Vol 24 (9) ◽  
pp. 951-960 ◽  
Author(s):  
C. R. Ford ◽  
C. E. Goranson ◽  
R. J. Mitchell ◽  
R. E. Will ◽  
R. O. Teskey

1981 ◽  
Vol 29 (3) ◽  
pp. 311 ◽  
Author(s):  
BR Tunstall ◽  
DJ Connor

Water input, soil water storage and plant water status were measured at monthly intervals over 2� years In a mature brigalow (Acacla harpophylla) forest. Redistribution of rainfall by the canopy was slight and stem flow averaged only 1.8%, but the direct loss of intercepted water accounted for 15% of the Annual ramfall In the wettest condltlon the soil stored 890 mm of water to a depth of 3 m The minimum sod water store measured under severe drought conditions was 840 mm when the dawn values of plant water potential were -6.8 MPa The soil water potentials below 1 m were consistently around -3.5 MPa due largely to high salt concentrations The tendency in a drying soil was towards a uniform profile of soil water potentlal, and soil water at depths below 1 m was extracted only when dawn plant water potentials were less than - 3.5 MPa Over monthly Intervals the maximum and minimum rates of evapotransplratlon were 3.3 and 0 .46 mm/d respectively, and the pattern of community water use was related to rainfall and not to potentlal evaporation. To survive in such an environment the plants develop and withstand extremely low water potentials associated wlth the low availability of water and the high evaporative demand.


Sign in / Sign up

Export Citation Format

Share Document