Medicinal plant species constitute a considerable part of the flora in Iran and play a major role in the composition of plant communities. Therefore, it is necessary to recognize the factors leading to the establishment and distribution of vegetation. For data sampling (2012), land units were specified. The plot size was determined using minimal area method and number of plots was determined by...

where SOC is the surface organic content; R, G, and B are image intensity values in the red, blue and green Past research has attempted to relate surface characteristics of soils bands, respectively; and a, b, c and d are curve-fit paramto reflectance from remotely sensed images to provide a means for quantifying spatial heterogeneity. Existing procedures have proven eters. The Chen et al. (200...

plant life and food production for human closely depend on fertile and healthy soil. knowledge about qualitative properties of soil and its potential production can contribute us in the plantation, fertilization, utilization and land management. in addition, rangelands cover a very large portion of the earth's surface and play an important role in food security and other ecosystem services. the...

soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. the present study was conducted to assess the ability of rangeland hydrology and erosion model for estimating sediment yield on rangeland’s hill slopes in dry regions at shahid noori paired watershed of kakhk. rhem is a mathematical, distribution and physical mod...

Digital elevation models of two “steady-state” mountain ranges, the Olympic Mountains (OM) and Oregon Coast Range (OCR), are used to examine relationships between slope distributions, the development of threshold hillslopes, and steady-state topography. Plots of drainage area versus slope for these mountain ranges exhibit substantial scatter that complicates comparison of range form to analytic...

In the Rio Negro basin, podzols develop at the expense of clay-depleted laterites through localised and spectacular weathering fronts. This natural process leads to the remobilization of previously accumulated organic matter (OM) and elements (Al, Fe, Si). OM is thus redistributed within soil profiles and exported towards rivers, giving them their typical black coloration. In soils, this redist...

medicinal plant species constitute a considerable part of the flora in iran and play a major role in the composition of plant communities. therefore, it is necessary to recognize the factors leading to the establishment and distribution of vegetation. for data sampling (2012), land units were specified. the plot size was determined using minimal area method and number of plots was determined by...