The analysis of the evolution of the chemical and biological characteristics of the Mediterranean marine ecosystem requires an integrated approach. Consistently, an ecosystem description, embedded in the MFSTEP one eighth degree threedimensional general circulation model, is tested and used following a twin experiment 5 approach. The ecosystem model is based on the NPZD trophic chain: inorganic...

Improved understanding of crop production systems in relation to N-supply has come from a knowledge of basic plant biochemistry and physiology. Gene expression leads to protein synthesis and the formation of metabolic systems; the ensuing metabolism determines the capacity for growth, development and yield production. This constitutes the genetic potential. These processes set the requirements ...

We examined the effect of climate on aboveground biomass allocation of ponderosa pine (Pinus ponderosa) by measuring trees in disjunct forest stands growing on the same substrate at high-elevation montane sites and low-elevation desert sites. Climatic differences between the sites were comparable to the difference between present and future climates of interior North America that is expected to...

Recent increases in Pinus ponderosa Dougl. ex Laws. forest density in the southwestern United States have severely reduced understory herbaceous biomass and altered understory species composition. To examine whether changes in graminoid species composition are caused by increased shading, we studied the effects of shade on leaf gas exchange, biomass, and reproductive characteristics of five gra...

Plants are dependent on exogenous nitrogen (N) supply. Ammonium (NH₄(+)), together with nitrate (NO₃(-)), is one of the main nitrogenous compounds available in the soil. Paradoxically, although NH4 (+) assimilation requires less energy than that of NO₃(-), many plants display toxicity symptoms when grown with NH₄(+) as the sole N source. However, in addition to species-specific ammonium toxicit...

An adjoint model is used for inverse modeling of black carbon during ACEAsia. We use the 4D-Var approach to optimally recover spatially-resolved anthropogenic and biomass burning emissions, and initial and boundary conditions of black carbon. Boundary conditions and biomass burning emissions are assigned daily scaling factors. Anthropogenic emissions are scaled by a combination of daily and mon...

Siroheme, an iron-containing tetrapyrrole, is the prosthetic group of nitrite reductase (NiR) and sulfite reductase (SiR); it is synthesized from uroporphyrinogen III, an intermediate of chlorophyll biosynthesis, and is required for nitrogen (N) and sulfur (S) assimilation. Further, uroporphyrinogen III methyltransferase (UPM1), responsible for two methylation reactions to form dihydrosirohydro...

BACKGROUND AND AIMS Recent studies have suggested that responses to shading gradients may play an important role in establishment success of exotic plants, but hitherto few studies have tested this. Therefore, a common-garden experiment was conducted using multiple Asian woody plant species that were introduced to Europe >100 years ago in order to test whether naturalized and non-naturalized sp...