the study of soil seed bank provides useful information on management and restoration of natural ecosystems. in the arid environments, some perennial plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. this study was conducted with objective to investigate effect of perennial plants on densit...

During last two decades studies on endozoochorous seed dispersal indicated that a large numbers of plant seeds are potentially dispersed and suceefully germinated via animal dung. However, very little is known about the relative importance of endozoochory in germination success of plant species in semi-steppe rangelands. In this paper we examined dung germinating seed content, seed deposition p...

We assessed changes in soils and vegetation associated with different plant life forms increasing grazing intensity (GI) a subhumid grassland of Patagonia (Argentina), vast portions these grass steppes degraded states. reconstructed the historic GI gradient study sites characterised cover. sampled soil beneath patches shrub their bare interspaces, as well height hummocks thickness superficial h...

Methods that are more cost-effective and objective are needed to detect important vegetation change within acceptable error rates. The objective of this research was to compare visual estimation to three new methods for determining vegetation cover in the sagebrush steppe. Fourteen management units at the US Sheep Experiment Station were identified for study. In each unit, 20 data collection po...

Correcting satellite imagery for atmospheric effects is a common procedure today. Indeed there are many techniques and software applications that offer atmospheric correction processes. This study compared several techniques (apparent reflectance, dark-object subtraction, Cos(t), and the full cost model) in both Idrisi and ENVI software to determine the level of similarity between resulting ima...

Cheatgrass (Bromus tectorum L.) is an invasive annual grass that increases wildfire frequency, degrades native ecosystems, and threatens agriculture across vast areas of the Western United States. This research examines how cheatgrass invasion may alter physical and biological properties of soils. Proliferation of very fine roots and high production of low-quality litter by cheatgrass increases...

Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an...