Stomatal frequencies of fossil-plant species are used to estimate past pCO2 levels based on the physiological functions of living taxa. There is a demonstrable inverse relationship between increasing pCO2 and stomatal frequency parameters, in which there is a decrease in both stomatal density (SD) and stomatal index (SI). Concentration of CO2 is not the only factor known to affect SD and SI val...

To date, the research community has failed to reach a consensus on the nature and significance of the relationship between climate variability and armed conflict. We argue that progress has been hampered by insufficient attention paid to the context in which droughts and other climatic extremes may increase the risk of violent mobilization. Addressing this shortcoming, this study presents an ac...

in line with an investigation regarding to evaluation of the compatibility of the asian pear cultivars with iran climatic conditions – currently being carried out at the horticultural department of tarbiyat modares university (tmu) – the present preliminary study was performed in two regions in isfahan. asian pear (pyrus serotina rehd.) cultivars (grafted on european pear seedling rootstocks) w...

The vegetation cover and rangeland production are the most important factors to determine the proper planning system for effective utilization and management of rangelands. In this research, the effect of climatic factors (temperature and rainfall) were studied on vegetation cover and forage production of four species (Festuca ovina, Bromus tomentellus, Dactylis glomerata and Agropyron trichoph...

[1] Permafrost soils store nearly half of global soil carbon (C), and therefore permafrost thawing could lead to large amounts of greenhouse gas emissions via decomposition of soil organic matter. When ice-rich permafrost thaws, it creates a localized surface subsidence called thermokarst terrain, which changes the soil microenvironment. We used soil profile CO2 measurements to understand the r...

Through the past 60 years, forests, now of various age classes, have been established in the southern part of the Korean Peninsula through nationwide efforts to reestablish forests since the Korean War (1950-53), during which more than 65% of the nation's forest was destroyed. Careful evaluation of long-term changes in vegetation growth after reforestation is one of the essential steps to ensur...

we estimated the rainfall interception loss (i), canopy storage capacity (s), the ratio of mean evaporation rate from the wet canopy () over the mean rainfall intensity () (mm h-1) (), and free throughfall coefficient (p) in a fraxinus rotundifolia mill. stand located in an afforested park land in a semiarid region of iran. for each storm event, i was calculated as the gross rainfall (gr) minus...

the effects of sowing date and crop density of chickpea on population and infestation of pod borers were studied in a randomized complete block design by factorial arrangement with three replications in the chickpea growing region of greet, khorramabad in 2007 until 2009. experimental factors comprised of sowing dates (march 14, march 30, and april 21) and crop density (25, 50 and 75 plant.m-2)...

Accurate assessments of spatio-temporal variations in gross primary productivity (GPP), evapotranspiration (ET), and water use efficiency (WUE) play a crucial role in the evaluation of carbon and water balance as well as have considerable effects on climate change. In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) products were used to quantify the mean annual GPP and ET at K...