Biogeographic barriers for freshwater biota can be effective at various spatial scales. At the largest spatial scale, freshwater organisms can become genetically isolated by their high mountain ranges, vast deserts, and inability to cross oceans. Isolation by distance of aquatic plants is expected to be stronger across than alongside mountain ridges whereas the heterogeneity of habitats among p...

Drylands occupy large portions of the Earth, and are a key terrestrial biome from the socio-ecological point of view. In spite of their extent and importance, the impacts of global environmental change on them remain poorly understood. In this introduction, we review some of the main expected impacts of global change in drylands, quantify research efforts on the topic, and highlight how the art...

A total of five specimens of Allactaga hotsoni were captured in Khorasan and Yazd provinces, Iran, in summer 2004 and 2005. The specimens are similar to those described previously from Baluchistan of Iran and Afghanistan. For the first time a karyological study was carried out to make a comparison with the other species. On the basis of karyological study there is not any significant difference...

Background: This research was investigated to evaluate effect of applying sunflower residues as a green manure on increasing zinc (Zn) concentration of two Iranian wheat cultivars in a Pb and cadmium (Cd) polluted soil. Methods: Treatments included the application of sunflower residuals grown in a Zn-polluted soil  at two levels of 0 and 8 t/ha, two wheat cultivars  in a soil contaminated with...

Ecophysiological models predict quantitative traits of one genotype in any environment, whereas quantitative trait locus (QTL) models predict the contribution of alleles to quantitative traits under a limited number of environments. We have combined both approaches by dissecting into effects of QTLs the parameters of a model of maize (Zea mays) leaf elongation rate (LER; H. Ben Haj Salah, F. Ta...