With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual, integrated a...

1. Catchments export nutrients to aquatic ecosystems at rates and ratios that are strongly influenced by land use practices, and within aquatic ecosystems nutrients can be processed, retained, lost to the atmosphere, or exported downstream. The stoichiometry of carbon and nutrients can influence ecosystem services such as water quality, nutrient limitation, biodiversity, eutrophication and the ...

this study concerns with calculation of iran's agricultural bilateral trade costs and major influential factors in iran's bilateral trade with developed and developing countries. the main findings revealed that over the period 1995-2010 weighted average of agricultural trade cost with developing partners has declined by 44, and with developed partners has increased by 22 percent. this reduction...

abstract according to the importance of date export in iran, this study investigates short run and long run relationship between date export and important economical variable, specifically exchange rate. for this purpose, an autoregressive distributed lag approach (ardl) to cointegration is applied to annually time-series data from 1981 to 2007. results showed that the exchange rate, export pri...

the sources of output growth of iranian agriculture over the years 1986-2001 has been examined, using a decomposition method within the input-output (io) framework. the three comparable io tables of 1986, 1991, and 2001 have been employed as the main data sources. output changes from a demand side perspective, and decomposition of the growth of output into components attributable to consumption...

Agriculture is a major part of sub-Saharan Africa’s economy, but its expansion poses significant threats to great ape habitats and forests. The sector accounts for nearly onequarter of the continent’s gross domestic product (GDP) and, in one way or another, it employs nearly two-thirds of its labor force (UNECA, 2013, 2014). The production of agricultural commodities—for both subsistence and ex...

Agriculture is a major part of sub-Saharan Africa’s economy, but its expansion poses significant threats to great ape habitats and forests. The sector accounts for nearly onequarter of the continent’s gross domestic product (GDP) and, in one way or another, it employs nearly two-thirds of its labor force (UNECA, 2013, 2014). The production of agricultural commodities—for both subsistence and ex...

Agriculture is a major part of sub-Saharan Africa’s economy, but its expansion poses significant threats to great ape habitats and forests. The sector accounts for nearly onequarter of the continent’s gross domestic product (GDP) and, in one way or another, it employs nearly two-thirds of its labor force (UNECA, 2013, 2014). The production of agricultural commodities—for both subsistence and ex...