BACKGROUND AND AIMS Epiphytism imposes physiological constraints resulting from the lack of access to the nutrient sources available to ground-rooted plants. A conspicuous adaptation in response to that lack is the phytotelm (plant-held waters) of tank-bromeliad species that are often nutrient-rich. Associations with terrestrial invertebrates also result in higher plant nutrient acquisition. As...

Seasonal variations in leaf nitrogen, phosphorus and potassium concentrations were studied in a mature carob (Ceratonia siliqua L. cv "Mulata") orchard subjected to a 4-year irrigation and fertilization experiment. Three irrigation regimes (0, 50 and 100%), based on the evaporation values obtained from a class A pan, were tested in combination with two nitrogen (N) supply regimes in which 21 kg...

Young individuals of a single black cottonwood (Populus trichocarpa Torr. & Gray) clone were raised for three growing seasons in whole-tree chambers and exposed to either ambient or elevated atmospheric carbon dioxide concentration ([CO2]), with either a high or a low mineral nutrient supply, in a factorial experimental design. Nutrient availability had a larger effect on growth and dry matter ...

Allocation of limited nutrients, such as nitrogen (N) and phosphorus (P), among plant organs reflects the influences of evolutionary and ecological processes on functional traits of plants, and thus is related to functional groups and environmental conditions. In this study, we tested this hypothesis by exploring the stoichiometric scaling of N and P concentrations between twig stems and leaves...

Sunflower (Helictnthur annuus L. cvs Mehr Shafagh) seedlings were grown in nutrient solutions containing 20.5 to 70.4 mM NaCl and 0 as the control. The effects of salinity on developmental changes occurring in the shoot apices of plants were studied. At 20.5 mM NaCI concentration, the leaf emergence rate and plastochron index of Shafagh increased significantly, but this phenomenon was not o...

Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch) trees grown in the field and sugar beet (Beta vulgaris L. cv. "Orbis") grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush...

sunflower (helictnthur annuus l. cvs mehr shafagh) seedlings were grown in nutrient solutions containing 20.5 to 70.4 mm nacl and 0 as the control. the effects of salinity on developmental changes occurring in the shoot apices of plants were studied. at 20.5 mm naci concentration, the leaf emergence rate and plastochron index of shafagh increased significantly, but this phenomenon was not obser...

Anthropogenic activities have caused important increases in soil Cu levels not only in urban areas but also in croplands. This study was designed to find out the effect of different concentration of copper on physiological and biochemical changes in Eucalyptus camaldulensis seedlings. Seeds of Eucalyptus camaldulensis were grown in marble chips and irrigated with nutrient solution mixed with co...

The plant, Camellia sinensis (leaves) is popularly known for its usage as tea in many parts of the world, including Nigeria. purpose this study was to screen bioactive compositions and determine endogeneous antioxidant potentials fresh processed (tea) C. aqueous leaf extract. Phytochemicals, minerals vitamins analysis were carried out following standard procedures. extracts further administered...

Stream ecosystems rely heavily on the input of allochthonous organic matter, such as leaves, as a primary source of nutrients. Within the macroinvertebrate community, shredders are an essential component in the process of leaf litter breakdown in streams and are largely responsible for the conversion of coarse particulate organic matter (CPOM) into fine particulate organic matter (FPOM) (Rincon...