We tested the hypothesis of a negative relationship between vegetation characteristics and ant species richness in a Brazilian open vegetation habitat, called candeial. We set up arboreal pitfalls to sample arboreal ants and measured the following environmental variables, which were used as surrogate of environmental heterogeneity: tree richness, tree density, tree height, circumference at the ...

Negative impacts of gully erosion in marly areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate gully thresholds related to plant vegetation cover and landuse change in the Agriculture (AG), Fair Rangeland (FR) and Weak Rangeland (WR) areas of Ghaasr-e-Shirin, Kermanshah, I...

harvester ants are known as one of the most renowned bio-disturbances in the arid and semi-arid ecosystems that affecte vegetation by collecting seeds and harvesting plants. it seems that physiognomy of plant association in steppe shrub land of roodshoor, saveh, iran has been highly changed by harvester ants’ activities that caused to conduct this research. the study was carried out on active a...

Floodplain roughness parameterization is one of the key elements of hydrodynamic modeling of river flow, which is directly linked to safety level estimation of lowland fluvial areas. Necessary input parameters are median grain size for unvegetated areas, vegetation density for forest and vegetation height and density for herbaceous vegetation. This paper presents a method for spatially distribu...

Here, I describe the geographical distribution of the savanna types in Namibia and identify the factors controlling the occurrence of each savanna type in relation to the amount of annual precipitation and the various physiographical regions, including the mopane ( Colophospermum mopane) area. The different types of savanna can be distinguished on the basis of the leaf habits of the dominant ve...

this study was performed in order to investigate the changes in vegetation and soil properties in compartment no.317 (managed forest) and no.318 (control forest) of jamand district of golband forest in mazandaran (noshahr). for this purpose, random-systematic sampling method with regular grid of 100×200 m was used to locate samples. the plot size was 400 m2 considering to tree and shrub species...

the vital need for river management is understood and predict of bank erosion processes. almost models will not be able to evaluate bank erosion,accurately. bstem model is the most usable model in many of river engineering projects in the world. necessary data for this model are related to driving and resisting forces controlled by hydraulic and geotechnical processes. these data include geomet...

Abstract. Rangeland vegetation dynamics encompass all processes of changes in vegetation composition and structure over time. Investigating the rangeland ecosystem dynamics makes it possible to determine the effects of climatic and management conditions on qualitative and quantitative changes of the vegetation in a specific period of time. Accordingly, data collection and measurements for evalu...