in order to evaluate the effect of ducks number on weeds diversity and density in paddy fields, an experiment was conducted at sari agricultural sciences and natural resource university during growing season of 2011-2012. experiment was arranged in split plot based on complete randomized block design with four replications. main factors were duck number at three levels (consisting of control, 4...

the tomato leafminer, tuta absoluta (meyrick), is one of the most important pests of tomato, solanum lycopersicum l., in iran. in this research, natural enemies diversity of t. absoluta and proportion of predators or parasitoids density to moth eggs or larvae density on five tomato cultivars including super strain b, super chief, mobil, korral, and early urbana y were studied in an experimental...

this study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. the study was carried out in steppe rangelands of saveh, markazi province, iran. four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. to study various vegetation and...

assessment of diversity and species richness in the understanding of ecosystem functions, protect and preserve genetic resources, evaluation and control of environmental change and the success or failure will help natural resource management programs. arbitrary banning livestock grazing program and one of the most common and perhaps the most degraded pastures and reduced the diversity and speci...

The Mirabad protected area (S. Azarbaijan, Iran) has a variety of ecological nurseries due to elevation of the sea, physiographic factors, micro-climates and soil types, and has high vegetation diversity. Mirabad protected area in the Piranshahr-Sardasht axis is between the latitudes of 36° 23' and 36° 31' north, and the lengths 45° 15' and 45° 25', with an area of ​​11435 ha, in the elevation ...

Seagrasses and associated macrophytes are important components of coastal systems as ecosystem engineers, habitat formers, and providers of food and shelter for other organisms. The positive impacts of seagrass vegetation on zoobenthic abundance and diversity (as compared to bare sands) are well documented, but only in surveys performed in summer, which is the season of maximum canopy developme...

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...