Journal of Rangeland

Many studies in recent years have investigated biodiversity at the level of individuals or species and less attention has been paid to the relationships of species to higher taxonomic levels. New indicators of taxonomic diversity by considering the relationships between species distribution at different levels of relatedness relative to other more conventional indicators of biodiversity provide more information for ecologist on the higher level of taxa. In this study using new indices of taxonomic diversity, was conducted on the taxonomic diversity and distinctness of plant species in six rangeland sites around Tehran province in the six taxonomic levels. The results showed that Saveh and Salafchegan allocated the most (∆=67.8, ^*∆=71.3) and the least (∆=61.4, ^*∆=64.4) taxonomic diversity and taxonomic distinctness indices, respectively. This means that there are a lot of high path along the phylogenetic tree species in Saveh site. The average index of taxonomic distinctness shows there are fewer orders for entire families and species in Salafchegan (Δ⁺=65.2). Results indicated that Salafchegan, Alborz and Damavand sites compared with Saveh, Firouzkouh and Semnan sites had more relative speciation and heterogeneous evolutionary structures. In other words, large part of these sites often has gathered asymmetrical in small number of families. In general taxonomic diversity indices along with other species diversity indices can be used to assess more complete and more comprehensive view of biodiversity and ecosystem process particularly in rangelands community analyses.

This research was carried out to study the distribution pattern of Artemisia fragrant and Bromus tomentellus in Razan-Khushvash mountainous rangelands located around Noor city. Random- systematic approach was used to collect the data along three 100 meters transects within the 2200 and 2400 elevation range. Ten random points along each transect with distance of 10 m were selected and the data were collected from 30 points. The distance of to the nearest plant to the selected random points, that plant to nearest neighbor plant and distance of random point to second nearest plant were measured. One square meter plots were placed at the random points and the numbers of plant individuals were also counted. The plant distribution indices (Eberhart, Hopkins, Holgate, Johnson and Zimmer) were then calculated. The quadratic indices of species dispersal (Variance mean, Green, Lloyd, Morisita and Standard Morisita) were also calculated. One hundred percent inventories as control were conducted in 100m² and 200m² plots for Bromus tomentellus and Artemisia fragrant respectively. According to the calculated indices (Eberhart, variance mean, green, Morisita and standard Morisita), Artemisia fragrant had clumped pattern in the study area. Bromus tomentellus had a random to clumped pattern based on some calculated quadrate indices as it was confirmed by the one hundred percent inventory. Although the obtained results from Variance mean, Green, Morisita and standard Morisita indices showed a clumped pattern for Bromus tomentellus, Hopkins index showed a random pattern for the species.  Overall, quadratic indices can be recommended to study the spatial pattern of the species in the study area compared to distance methods.