In this study, some habitat characteristics of Iranian rose (Hulthemia persica) were studied in Gonbad watershed in Hamedan providence, Iran. Soil samples were taken by a systematic randomized method at elevation 2000-2400 m above sea level. Samples were taken from 0-30 cm depth. In the laboratory, N, P, K% and organic matter (OC%), soil acidity (pH), conductivity (EC) and soil texture were det...

This study shows the effect of soil structure, soil texture and different types of nutrients on the growth of Ammi visnaga (L.) Lam, as well as the yield of the fruit crop and its content of the main active principals (ɣpyrones). The study was carried out in several localities in Two Arabian countries in North Africa; Egypt and Sudan. Egypt: at three localities:-1st at Mepaco Farm in Enshas El-...

Tree species response to climate change-induced shifts in the hydrological cycle depends on many physiological traits, particularly variation in water relations characteristics. We evaluated differences in shoot water potential, vulnerability of branches to reductions in hydraulic conductivity, and water source use between Pinus contorta Dougl. ex Loud. var. latifolia Engelm. (lodgepole pine) a...

Host-associated organisms (e.g., parasites, commensals, and mutualists) may rely on their hosts for only a portion of their life cycle. The life-history traits and physiology of hosts are well-known determinants of the biodiversity of their associated organisms. The environmental context may strongly influence this interaction, but the relative roles of host traits and the environment are poorl...

Lack of information about the spatial variability of soil C in different management systems limits accurate extrapolation of C sequestration findings to large scales. The objectives of this study were to: (i) describe and quantify variability of total C in three management systems, chisel-plow (CT) and no-till (NT) with conventional chemical inputs and a chisel-plow organic management practice ...

The microbial ecology of the nitrogen cycle in agricultural soils is an issue of major interest. We hypothesized a major effect by farm management systems (mineral versus organic fertilizers) and a minor influence of soil texture and plant variety on the composition and abundance of microbial nitrifiers. We explored changes in composition (16S rRNA gene) of ammonia-oxidizing archaea (AOA), bact...

geostatistical approaches have great importance because they include spatial correlation of geographic data. present study evaluated the efficiency of geostatistical techniques and demonstrated their capabilities in studying the soil variables(soil texture (sand percent), ec and so4-2) in the important plant community of nitraria schoberi in meighan desert, arak. a regular grid on the map compr...

This paper addresses and documents a number of issues related to the implementation of an advanced land surface–hydrology model in the Penn State–NCAR fifth-generation Mesoscale Model (MM5). The concept adopted here is that the land surface model should be able to provide not only reasonable diurnal variations of surface heat fluxes as surface boundary conditions for coupled models, but also co...