Theoretical considerations have suggested that there may be differences in photosynthetic nitrogen use efficiency (PNUE) among plants that use different biochemical variants of C(4) photosynthesis. To test this hypothesis we examined the leaf nitrogen content and photosynthetic rates of six grass species (three of C(4) subtype NAD-ME and three of C(4) subtype NADP-ME) grown over a wide range of...

J. M. H. Knops,* K. L. Bradley and D. A. Wedin School of Biological Sciences, School of Natural Resource Sciences, University of Nebraska, 348 Manter Hall, Lincoln, NE 68588, USA. *Correspondence: E-mail: [email protected] Abstract Plant species are hypothesized to impact ecosystem nitrogen cycling in two distinctly different ways. First, differences in nitrogen use efficiency can lead to positiv...

We investigated the variation in leaf nitrogen to phosphorus ratios of tropical tree and liana seedlings as a function of the relative growth rate, whole-plant water-use efficiency, soil water content and fertilizer addition. First, seedlings of 13 tree and liana species were grown individually in 38-l pots prepared with a homogeneous soil mixture. Second, seedlings of three tree species were g...

This study aimed to assess the level of nitrogen species in patients presented with acute myocardial infarction and to relate the levels of nitrogen species to the infarction site. A total number of 113 patients admitted to the intensive care unit at Diyala Teaching Hospital. The patients were presented within 6 hours of pain onset and diagnosed as acute myocardial infarction using electrocardi...

Nitrogen deficiency promotes lipid formation in many microalgae, but also limits growth and lipid productivity. In spite of numerous studies, there is poor understanding of the interactions of growth and lipid content, the time course of lipid accumulation and the magnitude of nitrogen deficiency required to stimulate lipid formation. These relationships were investigated in six species of olea...

the study was performed for assess the environmental factors affecting weed species diversity and composition of wheat (triticum aestivum l.) fields in jajarm, north-khorasan of iran, in 2009. the crop management (herbicide, amount of nitrogen applied and preceding crop type) and edaphic factors (ph, texture and content of phosphorus) of 16 fields were collected. shannon’s diversity index, spec...

Leaf size indices of the tree species in the peatland of Agusan del Sur in Mindanao in Philippines was examined to deduce the variation of forest structure and observed forest zonation.  Using raunkiaer and webb’s leaf size classification, the leaf morphometrics of seven tree species consistently found on the established sampling plots were determined.  The species includes Ternstroemia phi...