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Superabsorbent polymers (SAPs) have shown to be quite effective and useful in acting as a reservoir for water and some nutrients in arid and semiarid regions. There are many studies in Iran that have been performed in relation to SAPs and their useful application in agriculture; however, there is still a lack of its applied definition in arid regions. Therefore, this study was conducted with the aim of doing a meta-analysis of the results of studies conducted in Iran and answering a general question about whether the application of SAPs has been effective in enhancing the production or not, and if so, how much of SAP is recommended. To conduct this research, articles published during 2006–2016 on the subject of the effects of different rates of SAP application on yield and yield components of crops (including cereals, legumes, and medicinal and grassland plants) were investigated. The results of the meta-analysis showed that the mean consumption rate of SAPs for cereals, legumes, and medicinal and grassland plants was 83, 322, 1031, and 210 kg ha−1, respectively, and that, at these SAP application rates, the mean seed yield in cereals, medicinal plants, and legumes increased by 15.2, 12.6, and 38% (equivalent to 1059, 345, and 452 kg ha−1), respectively, compared with the control. Dry matter response to superabsorbent application was slower compared with the seed yield response. The mean consumption of 83 kg ha−1 of superabsorbent for cereals increased seed yield by 15.2% on average. According to the results, it seems that the application of 100 kg SAP ha−1 is the most appropriate rate for increasing seed and dry matter yields and satisfying economic aspects. These study findings may shed light on the environment and socioeconomic concerns and improve efficacy and reduction of costs.

Rangelands are natural ecosystems containing a range of resources of genetic diversity and numerous plant species and its evaluation has always been essential. However, biodiversity is one of the most important components of habitat assessment and the identification and introduction of the flora of an area is one of the significant operations that can be used in order to optimize the utilization of the available natural resources. Baharkish rangeland is located at a distance of about 60 km south of the city of Quchan. The rangeland’s average elevation is about 2069 m above sea level, with its lowest at 1740 m and highest at 2440 m. Baharkish rangland in over a ten year period had the average annual rainfall of 337 mm and 998.2 mm evaporation as well as average annual temperature of 9.4°C, respectivelly. The results of the research conducted in the spring of 2014, showed that the total study area includes 77 species from 22 families with Poaceae, Asteraceae, Lamiaceae, Fabaceae, Apiaceae and Brassicaceae being the dominant families with 18%, 13%, 12%, 9%, 8% and 6% respectively. Classification of life form according to Raunkiaer method showed the dominance of the hemicryptophytes with the greatest abundance 41%, followed by Chamaephytes, Therophytes, Geophytes, Phanerophytes and Cryptophyte with 25%, 23%, 4%, 4% and 3% of species were the dominant life forms of the area. In terms of geographical distribution, the Irano-Turanian plant species with 64% obtained the maximum value. Keywords: Flora, Geographical distribution, Life form, Raunkiaer

The article was retracted because of there was an error on it. The researcher can find the corrected version on May 2017 issues vol 21 no. 3 ( https://www.ajol.info/index.php/jasem/article/view/158830 ) Rangelands are natural ecosystems containing a range of resources of genetic reserves and numerous plant species and its evaluation has always been essential. However, biodiversity is one of the most important components of Habitat assessment and the identification and introduction of the flora of an area is one of the significant operations that can be used in order to optimize the utilization of the available natural resources. Baharkish rangeland is located at a distance of about 60 km south of the city of Quchan. The rangeland’s average elevation is about 2069 m above sea level, with its lowest at 1740 m and highest at 2440m. Baharkish rangland in over a ten year period has had the average annual rainfall of 337 mm and 998.2 mm evaporation as well as average annual temperature of 9.4°C, respectively. The results of the research conducted in the spring of 2014, showed that the total study area includes 22 species from 78 families with Poaceae, Asteraceae, Lamiaceae, Apiaceae, Brassicaceae, Caryophyllaceae and Papilionaceae being the dominant families with respectively 19, 15, 12, 9, 8, 7 and 5 frequencies. Classification of biological Form according to Raunkiaer method showed the dominance of the hemicryptophytes with the greatest frequency (42%), followed by Therophytes, Chamaephytes, Cryptophyte, and Phanerophytes with 30%, 15%, 8% and 5% of species are the dominant life forms of the area. In terms of geographical distribution, the Iran-Turanian plant species with the frequency of 63% obtained the maximum value. Keywords: Biological form, Flora, Geographical distribution, Plant vegetation, Raunkiaer