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As Ankara is morphologically situated in a basin,this causes air conditions of poor quality for the city-dwellers, and suchadverse conditions are further increased sometimes with the impact of urbanheat island (UHI). In this study, mobile measurements were made for 12 months(1 at daytime and 1 at nocturnally) to determine the characteristics of UHI inAnkara, and the results were assessed and analyzed using statistical methods. Basedon the assessments, the northern cliff of the city is formed at Yükseltepe intersectionand the southern cliff is formed at Turan Güneş Street. There are also twodifferent peaks in Ulus and Kızılay, and the plateau of the urban is between the cliffs and peaks. Theplateau of the urban includes a temperature sinks and hills, which is caused bythe land use in the urban, heavy traffic and characteristics of urbanstructure. UHI formed in the urban becomes more apparent in the summer season (inthe arid period) and is decreased by 0.2 °C during the day and 0.4 °C at nightas the temperatures go far away from the city center. The temperatures drop inthe sites where visibility of sky is increased. The elevation is effective inthe temperature distribution, this is especially effective in the high pressureconditions., Ankara’nın morfolojik olarak bir çanakta yeralması, şehir sakinleri için kalitesiz hava koşulları yaratmakta, bu olumsuzkoşullar bazı dönemlerde şehir ısı adası (ŞIA) etkisiyle daha da artmaktadır. Buçalışmada, Ankara şehrinde ŞIA’nın özelliklerinin belirlenmesi amacıyla 12 ayboyunca her ay için 1 gece 1 gündüz mobil ölçümler yapılmış, sonuçlardeğerlendirilmiş ve istatistiksel yöntemler kullanılarak analiz edilmiştir. Budeğerlendirmelere göre, şehrin kuzey falezi Yükseltepe Kavşağı’nda, güneyfalezi ise Turan Güneş Caddesi’nde oluşmaktadır. Ulus ve Kızılay’da iki ayrızirve meydana gelmekte, falez ve zirveler arasında ise şehir platosu yeralmaktadır. Şehir platosu içerisinde sıcaklık çukuru ve tepeleri görülmekte, budurum şehir içi arazi kullanımı ve trafik yoğunluğu ve şehir yapısıözelliklerinden kaynaklanmaktadır. Şehirde oluşan ŞIA, yaz aylarında (kurakdönemde) daha belirginleşmekte, sıcaklıklar şehir merkezinden uzaklaştıkçagündüzleri 0,2 geceleri 0,4 °C azalmaktadır. Gök görüş oranı değerlerininarttığı sahalarda sıcaklıklar düşmektedir. Sıcaklık dağılışında yükselti deetkili olmakta, bu durum özellikle yüksek basınç koşullarında daha görünür halegelmektedir.

Th e rainfall erosivity index is one of the most important factors infl uencing soil erosion. For this reason, investigating the accuracy of rainfall erosivity indices is very important in diff erent climatic regions. Th e objective of this research was to investigate diff erent rainfall erosivity factors and determine the most appropriate ones for use in the central and northeastern parts of Iran. For this reason, necessary data were collected from 92, 6 and 10 soil erosion research plots in Khorasan Razavi, Semnan and Isfahan provinces, respectively. Th e rainfall intensities were recorded, as was the sediment yield associated with storm events, and 63 diff erent erosivity indices based on rainfall intensity were computed for these soil erosion research stations. Th e results demonstrated that the rainfall intensity-based indices had the most signifi cant correlations, with results of 0.740 (P < 0.01), 0.651 (P < 0.01) and 0.976 (P < 0.01) for sediment yield in Khorasan Razavi, Semnan, and Isfahan, respectively. Th ese selected rainfall intensity-based indices were also computed for synoptic stations. Rainfall erosivity indices, based on the amount of rainfall, were also computed for all soil erosion research plots and synoptic and climatic stations. Th e results showed that mean annual rainfall displayed a signifi cant correlation with selected rainfall intensity-based indices (r = 0.83 and 0.99, P < 0.01) in the synoptic stations of Semnan and Khorasan Razavi, and the modifi ed Fournier index showed a signifi cant correlation with selected rainfall intensity-based indices (r = 0.90, P < 0.01) in Isfahan. Selected regression models were used to estimate the rainfall intensity-based indices at stations without intensity data in the studied provinces.

Isotope geochemistry of lacustrine carbonate represents a powerful tool to reconstruct paleoclimatic and paleoenvironmental conditions. Here, we present a comprehensive set of long-term oxygen (delta O-18) and carbon (delta C-13) stable isotope records from 5 Chattian to Burdigalian lacustrine sequences distributed over the Central Anatolian Plateau. Field relationships combined with stable isotope geochemistry indicate a relatively humid subtropic Late Oligocene climate with an environment characterized by large, temporally open freshwater lakes. Approximately during the middle Aquitanian, a 4 parts per thousand-5 parts per thousand increase in lake delta O-18 values indicates changes in regional climate including more arid conditions and an increasing dominance of closed saline lake conditions in the central plateau region. This time period was also characterized by frequent climatic fluctuations such as short-lived humid periods, possibly recording the influence of seasonality, topography, and the waxing and waning of aridity. In general, relatively high Oligo-Miocene delta O-18 lake water values within the modern plateau interior, even for the least evaporative sequences, suggest the absence of significant orographic barriers at both the northern and southern plateau margins prior to 20-16 Ma.

Flora inhabiting gypsum outcrops in arid environments shows a high level of specialization. However, the processes involved are still unclear, specifically at the key stage of germination. Here, to assess whether gypsum could chemically influence seed germination, we tested the germination of species according to 3 functional groups: gypsophiles, gypsovags, and calcicoles. A total of 24 taxa were selected, all occurring in gypsum and limestone substrates, under a semiarid and dry Mediterranean climate. Three levels of gypsum (CaSO4.2H2O) solution (low = 0.5 g/L, medium = 1 g/L, and high = 2.4 g/L) and 1 control treatment of distilled water were tested. Results depended on the particular species rather than on the functional group. We found that gypsum favored germination in some species (Lepidium subulatum L. and Gypsophila struthium L.), whereas significant negative effects appeared for only 1 species (Rosmarinus officinalis L.). In contrast, most of the species studied responded neutrally to gypsum solutions. Our results suggest that chemical features of gypsum could offer an advantage at the germination stage for certain species, rather than posing a constraint for seed germination.

Dünya üzerinde geniş alanlar kaplayan kurak ve yarıkurak alanlar, ormancılık çalışmaları için zor ve karmaşık teknikleri gerektirmekte, özellikle silvikültür çalışmalarında farklı uygulamaları zorunlu kılmaktadır. Söz konusu alanlarda iklim ve toprak özellikleri gibi olumsuz koşullar nedeniyle fidanlık ve bitkilendirme çalışmaları ılıman kuşaktakilere oranla büyük ölçüde farklılık göstermekte olup daha fazla deneyim ve teknik bilgi de gerektirmektedir. Başarı açısından kurak ve yarıkurak alanlarda kaplı fidan kullanımı kaçınılmaz olmaktadır. Bu çalışmada kuraklık olgusu, ülkemizde ve dünyadaki kurak alanlar hakkında bilgi verildikten sonra, bu gibi sahalarda uygulanabilecek bazı fidanlık teknikleri genel hatlarıyla ortaya konularak özellikle kurak alanların ıslahında kullanılacak kaplı fidanların nitelikleri üzerinde durulmuştur Arid and semi-arid areas, which cover wide areas on the earth, requires difficult and complex forestry techniques, notably different applications in silvicultural operations. Nursery and plantation techniques in such areas differs considerably compared to those in temperate zones, because of unfavorable conditions like climate and soil characteristics. For this reason, experience and adequate technical knowledge are required. Using containerized seedling becomes an obligation in arid and semi-arid regions to reach success. In this study, gives information about aridity term, arid and semi-arid areas in the country and in the world, then provides a clear understanding of some nursery techniques in such areas in a general manner. Especially properties of containerized seedlings, which will be used in reclamation of arid areas, are discussed.