in order to evaluate the weed diversity in forage crop fields such as alfalfa (medicago sativa l.), clover (trifolium sp.) and sainfoin (onobrychis spp.) in different provinces of iran, a study was conducted by using data from reports of plant protection organization, ministry of agriculture during 2008. after evaluation of weed species and definition of weed family, these species classified ba...

gonabad located at khorasan razavi and coordinates 580 30’ n 34o 35’ e. the highest point of the zone belongs to peak of siah mountain (height of 2,863 meters above sea level) and the lowest place has height of 810 meters above sea level, which is located in north west in salt desert. the mean temperature of the warmest and coldest of year is 29.3 and 3.9 respectively. moreover, mean of rainfal...

The community structure of hard and soft corals, with an emphasis on hard corals, was determined by means of line-transects on 9 onand off-shore reefs of different type and different wave exposure in the Northern Red Sea near Hurghada in Egypt. Coral communities were found to differentiate along a horizontal windand wave-exposure gradient. Exposed communities were dominated by Acropora species,...

Because the quantity, quality, and heterogeneity of resources should affect the diversity of consumers, plant productivity, plant composition, and plant diversity may influence the diversity of trophic levels higher up the food chain (‘‘bottom-up’’ control of diversity). Increasing plant productivity may increase herbivore diversity by: increasing the abundance of rare resources (‘‘resource rar...

Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

This article presents an analysis of plant species richness and diversity, concerning some climatic variables along a 1500-m elevation gradient on the Binalood Mountain in Heydari Wildlife Refuge (HWR), northeastern Iran.  Two hundred and thirteen nested-sampling quadrats were established and the abundance of the plants was recorded. Vegetation sampling was carried out from 2014 till 2016, foll...

A field survey was conducted in Wukari, Taraba State to assess the diversity and abundance of insect species in selected habitats (residential, open field made up of grassland and an agroecosystem). Sampling were done biweekly using light, pitfall and yellow pan traps set in 3 replicates, 30 m apart. Insects recovered were wet preserved in 70% ethanol except butterflies and moths. Representativ...

Plant Diversity conservation is a main objective in rangelandmanagement. Plant diversity is a suitable index for showing the changes ofvegetation in rangelands and has a high correlation with ecosystem parameters.Therefore, using this index it is possible to find the changes and manage theecosystem correctly. The current research was performed to determine the speciesdiversity in Fashandak rang...