annual fires might change many soil physical properties in semi steppe rangeland.the objective of this study was to investigate the impact of fire on soil physical properties and soil water infiltration parameters in semi-steppe rangeland of karsanak region in chaharmahal and bakhtiari province. therefore, several sites were chosen which were affected by fire at three, two and one years prior t...

The hypothesized presence of large regions of grass and forb-dominated "steppe tundra" across Alaska and Siberia during the Pleistocene glacial epochs has led to a search for modern analogs. Evidence is presented for the presence of steppe vegetation on south-facing slopes and summits of pingos within the central Arctic Coastal Plain of Alaska. Vegetation, floristics, soils, and climatic factor...

Vegetation light use efficiency (LUE) is a key parameter of Production Efficiency Models (PEMs) for simulating gross primary production (GPP) of vegetation, from regional to global scales. Previous studies suggest that grasslands have the largest inter-site variation of LUE and controlling factors of grassland LUE differ from those of other biomes, since grasslands are usually water-limited eco...

Previous work in climatically similar sagebrush steppe, USA and Patagonian steppe, Argentina suggested that a more intense evolutionary history of grazing in Patagonia selected for graminoids of lower forage quality, resulting in a plant community more resistant to livestock grazing. Here we consider whether subtle abiotic differences might create greater water or nutrient limitation in Patagon...

The genetic diversity found in domestic breeds allows farmers to develop new characteristics in response to changes in the environment, the appearance of diseases, or of modifications in market conditions. Indigenous breeds often possess gene combinations and special adaptations (such as disease resistance, adaptation to harsh conditions or poor-quality feeds) not found in other breeds. Five Ro...

An increasing amount of grasslands in Inner Mongolia of Northern China has been converted to cropland. The conversions in this extensive semiarid region have produced adverse ecological consequences at local and regional scales (e.g., dust storms). An important research need is to understand the fundamental ecosystem processes, such as energy and material fluxes, associated with the land conver...