About 35 samples were collected from lower and upper parts of the proposed Frasnianamennian boundary in three sections of Upper Devonian marine sediments of the Kerman province. The biostratigraphical and geochemical studies indicate that about 45% extinction of brachiopods probably caused by the Frasnian-Famennian bioevents, which is slightly higher than thr rate of Devonian-Carboniferous exti...

Excessively using fertilizers poses serious problems such as environmental pollution, soil degeneration, and quality yield reduction of vegetables. This study aimed to illustrate the effect different organic manure inorganic on characteristics soil, growth, yield, non-heading Chinese cabbage. There were 28 treatments in first experiment: no fertilization (CK), conventional (100% nitrogen T1), 2...

the kazhdumi formation of the bangestan group is a well-known and important source rock in most oil-fields in the zagros basin. in order to examine productivity of this formation in southwestern iran, and to correlate petrographical and palynological data with geochemical properties, one of the best outcrops of this formation, located in tange-maghar 45 km northwest of behbahan city, was sample...

Playa wetlands are important areas of soil organic carbon and nutrient storage in drylands. We conducted this study to assess how catchment biophysical variables control soil organic carbon and nitrogen in playas and how playas function differently than upland ecosystems. We found that playa organic carbon and nitrogen corresponded primarily with catchment vegetation cover and secondarily with ...

An overview of a comprehensive study of the behavior and fate of mercury in the estuarine Patuxent River is presented. Total Hg (HgT) and methylmercury (MeHg) exhibited weakly non-conservative behavior in the estuary. Total Hg concentrations ranged from 6 ng L 1 in the upper reaches of the sub-urbanized tidal freshwater river to <0.5 ng L 1 in the mesohaline lower estuary. Filterable (0.2 m) Hg...

to evaluate the nutritive value in some lignocellulosic materials, 3 sets of experiments were conducted on aspen, and grape woods. to enhance the digestibility, the woods were treated with 5% naoh. throughout the first trial, chemical composition and digestibility coefficients of dry matter, organic matter and ndf of experimental feeds, ph of rumen, as well as palatability were evaluated while ...

We compared forest floor depth, soil organic matter, soil moisture, anaerobic mineralizable nitrogen (a measure of microbial biomass), denitrification potential, and soil/litter arthropod communities among old growth, unthinned mature stands, and thinned mature stands at nine sites (each with all three stand types) distributed among three regions of Oregon. Mineral soil measurements were restri...