When stomata are open, the trade-off between water loss through transpiration and CO2 uptake via photosynthesis is a result of the evolutionary history of land plants from green algae. To supply the up to 1000-fold higher flux of water leaving the leaf compared with CO2 molecules entering the leaf during leaf gas exchange (Nobel 2009), plant hydraulics has evolved to be highly efficient. The in...

Potato and wheat plants were grown for 50 d at 400, 1000 and 10000 micromoles mol-1 carbon dioxide (CO2). and sweetpotato and soybean were grown at 1000 micromoles mol-1 CO2 in controlled environment chambers to study stomatal conductance and plant water use. Lighting was provided with fluorescent lamps as a 12 h photoperiod with 300 micromoles m-2 s-1 PAR. Mid-day stomatal conductances for pot...

Stomatal responses to light and humidity (vapor pressure difference, VPD) are important determinants of stomatal conductance. Stomatal movements induced by light are the result of a transduction of the light stimulus into modulated ion fluxes in guard cells and concomitant osmotic adjustments and turgor changes. It is generally assumed that this transduction process is a general stomatal proper...

Motivated by studies suggesting that the stomata of ferns and lycophytes do not conform to the standard active abscisic acid (ABA) -mediated stomatal control model, we examined stomatal behavior in a conifer species (Metasequoia glyptostroboides) that is phylogenetically midway between the fern and angiosperm clades. Similar to ferns, daytime stomatal closure in response to moderate water stres...

Predicting the large-scale consequences of drought in contrasting environments requires that we understand how drought effects differ among species originating from those environments. A previous meta-analysis of published experiments suggested that the effects of drought on both stomatal and non-stomatal limitations to photosynthesis may vary consistently among species from different hydroclim...

The impacts of Dust and Sand Storms (DSS) on people, crops, livestock, infrastructure and health are well documented. Data have accumulated on the deleterious effects of dust aerosols when they settle on plants. Sand blasting of low growing plants is a common cause of failure in reforestation efforts. Burial of plants by moving sands are also a cause of much damage. The physics of moving sand a...

abstract three pear genotypes (nazkeh, lasoreh and qevilah), grown in 2l containers, were studied under four irrigation regimes in order to evaluate the leaf relative water content (rwc), photosynthesis, leaf gas exchanges and plant dry weight induced by water stress. control treatment everyday was irrigation. irrigation was practiced when soil water potential reached at -0.4, -0.8, and -1.2 mp...

For a quantitative estimate of the ozone effect on vegetation reliable models for ozone uptake through the stomata are needed. Because of the analogy of ozone uptake and transpiration it is possible to utilize measurements of water loss such as sap flow for quantification of ozone uptake. This technique was applied in three beech (Fagus sylvatica) stands in Switzerland. A canopy conductance was...

through a model of stomatal conductance Jinzhi Wang Introduction I came to CGREC on May 7, 2008 to work under the direction of Dr. Xuejun Dong, eco-physiologist at the Center. His work involves the relationship between environmental factors (precipitation, temperature, and radiation) and soil respiration and plant physiology (leaf photosynthetic rates and leaf area index) of dominant species. O...