We examined open-grown Acer mono Maxim. trees of different sizes to test the hypotheses that (1) hydraulic limitation increases with tree size, thereby reducing photosynthesis, and (2) photosynthetic water- and nitrogen-use efficiencies change with tree size. Maximum net assimilation rate per unit dry mass was significantly lower in large trees than in small trees, whereas leaf nitrogen concent...

this research was performed to investigate the combined effect of soil salinity and compaction on some physiological characteristics of corn. for this purpose a factorial pot experiment on the basis of completely randomized design with three replications was performed. the experimental factors were three levels of soil salinity (saturated paste extract electrical conductivity 1.5, 2.5 and 4.5 d...

the possible alleviating effects of salicylic acid on protection of cowpea (vigna unguiculata) cv. parastu under water stress conditions were investigated in the university of zanjan agriculture research station during 2008. water stress was imposed by withholding irrigation at 50% flowering (flowering water stress, fws) and when 50% of the pods grew 2-3cm (pod-formation water stress, pfws). sa...

Leaf shrinkage with dehydration has attracted attention for over 100 years, especially as it becomes visibly extreme during drought. However, little has been known of its correlation with physiology. Computer simulations of the leaf hydraulic system showed that a reduction of hydraulic conductance of the mesophyll pathways outside the xylem would cause a strong decline of leaf hydraulic conduct...

Predawn leaf water potential (LWP), the LWP between 09:00 and 10:30 h (termed minimum LWP), stem xylem hydraulic conductivity, foliar nitrogen, leaf gas exchange and leaf traits were measured on the same days in adults and 1-year-old to 7-year-old resprouts that had regrown after removing all the aboveground shoots. Height growth and accumulation of aboveground biomass quickly decreased with re...

A study was conducted in the Shandong province in North China to investigate the effects of different planting patterns on water potential characteristics of soil-plant-atmosphere continuum (SPAC) and yield of summer maize. Three planting patterns were applied, i.e. bed planting (BE), furrow planting (FU) and flat planting (FL). The results showed that although soil moisture content in 0–20 cm ...

background and objectives: infunction of the photosynthetic apparatus of halophytes plays an important role in their salinity tolerance. kochia as a halophyte, is of high ability in biomass production in salinity stress conditions. thus study photosynthesis and the related factors salinity stress can provide appropriate physiological view for better understanding of the plant mechanisms of in s...

In the Mediterranean evergreen oak woodlands of southern Portugal, the main tree species are Quercus ilex ssp. rotundifolia Lam. (holm oak) and Quercus suber L. (cork oak). We studied a savannah-type woodland where these species coexist, with the aim of better understanding the mechanisms of tree adaptation to seasonal drought. In both species, seasonal variations in transpiration and predawn l...