Paleovegetation Researches Based on Fossil Pollen Analysis in Akgöl (Sakarya): Preliminary Results

Fosil polen analizleri göl çökelleri, turbalıklar, akarsu ve deniz sedimanları, buzullar, linyitler ve taş kömürleri gibi çeşitli ortamlardan elde edilen polenlerin_x000D_ araştırılmasını kapsamaktadır. Kuvaterner dönemine ait palinolojik çalışmaların önemli veri kaynaklarından biri de göllerdir. Araştırma alanı olarak seçilen_x000D_ Akgöl, Sakarya ilinde, Ferizli ilçesinin Gölkent mahallesinde bulunmaktadır. Gölün yüzölçümü 3,5 km2_x000D_ ve maksimum derinliği 8 m’dir. Bu çalışmanın amacı:_x000D_ gölün dip sedimanlarında fosil polen analizleri yaparak gölün çevresinde son 1000 yılda meydana gelen vejetasyon değişimlerini ortaya çıkarmaktır._x000D_ Akgöl’den karot alımında İTÜ EMCOL Araştırma Uygulama Merkezi’nin 4x4 m. platformlu piston karotiyeri kullanılmıştır. İstanbul Üniversitesi-Cerrahpaşa,_x000D_ Orman Fakültesi Orman Botaniği Anabilim Dalında bulunan Palinoloji Laboratuvarı’na getirilen karot üzerinde her 5 cm’de bir 2 cm3_x000D_ lük sediman örnekleri_x000D_ alınmıştır. Bu örneklerde “klasik yönteme” göre fosil polen analizi yapılmıştır. Hazırlanan polen preparatlarında her bir bitki taksonu için polen yüzdesi_x000D_ değerleri hesaplanmış, odunsu ve otsu taksonlara ait yüzde grafikleri TILIA adlı programda çizilmiştir. Polen diyagramından elde edilen ilk bulgulara göre;_x000D_ Akgöl ve çevresinde son 1000 yılda yaprak döken orman vejetasyonu hâkimdir. Bu doğal orman varlığının içine son yıllarda Gymnospermae taksonlarından_x000D_ sahil çamları da dikim yoluyla getirilmiştir.Fossil pollen analyzes include research of pollen grains from various environments such as lake sediments, peatland, river and marine sediments, glaciers,_x000D_ lignite and coal. Lakes are one of the important data sources for Quaternary palynological studies. Akgöl, which is selected as a research area, is located in Gölkent district of the Ferizli township in the provincial city of Sakarya. Its surface area is 3.5 km2_x000D_ and its maximum depth is 8 meters. The aim of this study_x000D_ was to investigate vegetation changes around Akgöl in the last 1000 years using fossil pollen analysis in the bottom sediments of the lake. The Piston corer_x000D_ of ITU EMCOL Research Centre was used for recovering sediment cores from Akgöl. Sediment samples of 2 cm3_x000D_ were collected every 5 centimeters on one_x000D_ of the cores at the Palynology Laboratory of IUC. Fossil pollen analysis was performed according to the “classical method”. The pollen percentage values_x000D_ were calculated for each plant taxa and relative abundance graphs were plotted in the TILIA program. According to preliminary results of the pollen_x000D_ diagram; deciduous forest vegetation has been predominant in the last 1000 years around Akgöl. Maritime pine was introduced into this natural forest by_x000D_ plantation in the recent year

Effects of humic acids from different sources on sodium and micronutrient levels in corn plants

The use of activated humic acids (HAs) in agricultural applications is a relatively recent development. Corn (Zea mays L.) is a major food and silage crop in Turkey and yields are reduced in calcareous soils by sodium (Na) toxicity and carbonate (CO3 ) induced deficiencies of some micronutrients. In this study, the effects of two HAs extracted using the wet-alkali technique and activated with nitrogen (N2 ) and oxygen (O2 ) gases, on the Na and micronutrient (iron (Fe), manganese (Mn), zinc (Zn), copper (Cu) and boron (B)) concentrations in the homogenised stems and leaves of corn plants were investigated. The experiment was conducted with a completely randomized design with factorial arrangement (2 HA types × 2 fertilisation regimes × 5 HA concentrations), with three repetitions, in a calcareous soil in pots in a greenhouse. The humic acid was applied at 100, 200, 400, and 800 mg/kg of soil before sowing the corn seed. The variance analysis showed that increasing HA levels decreased the Na concentration in the corn plants. The lowest plant Na concentrations were obtained with the addition of HA activated with N2 and O2 to both the fertilised and unfertilised treatments. The highest Zn and Cu uptakes, and Fe, Mn, and B uptakes, were associated with wet alkali extraction and gas activation, respectively. Overall, HA extracted with N2 /O2 was more effective under unfertilised conditions and wet extracted HA was more effective under fertilised conditions

The Characterization of the Arifiye peat

There is a fortune of the peat resources in Turkey, particularly around Lake Sapanca in Sakarya. There has been increasingly attention to peatlands in technological uses and agricultural applications. The Arifiye peat is a new resource. It needs to be elucidated by characterization of its chemical and physical properties. The objective of this study was to characterize a number of samples collected from fifteen different profiles of the peat (sapric) by measuring cation exchange capacity, water holding capacity, humic acid, fulvic acid, organic matter, organic carbon. In addition, the spectroscopic analysis suggested that the functional groups and molecular structure of the Arifiye peat resemble those of peatlands described previously in the literature

ENZYME ACTIVITIES OF PADDY SOILS AND RELATIONSHIPS WITH THE SOIL PROPERTIES

This study was carried out to determine the effect of soil properties on enzyme activities of paddy soils, the sample of which were taken from Üçpınar, Harız, Doğancı, Kaygusuz, Emenli, Sarıköy and Gelemenağarı villages where rice cultivation is an intensive agricultural system. In this study, soil properties having effects on urease, phosphatase, ß-glucosidase and catalase enzyme activities were setforth. Urease enzyme activities of soil samples varied from 24.12 to 39.03 mg N 100 g dry soil -1 . Significant correlations were determined between urease enzyme activities and organic matter (r = 0.89**), extractable Mn (r = 0.74**), exchangable K (r = 0.73**) and total P content of soil (r = 0.81*). Acid phosphatase enzyme activity varied between 3.00-17.44 mg phenol 100 g dry soil -1 , alkaline phosphatase enzyme activity between 12.00-25.53 mg phenol 100 g dry soil-1 . Exchangable Mg (r = 0.71*) and extractable Cu (r = 0.74*) were found to have positive effect on acid phosphatase enzyme activity and pH (r = 0.73*), exchangable Ca (r = 0.74*), exchangable Mg (r = 0.71*), exchangable total basic cations (r = 0.79*) and extractable Cu (r = 0.70*) had positive effects on alkaline phosphatase enzyme activity, whereas total P (r = - 0.84**) affected the activity negatively. ß-glucosidase enzyme activity was measured to vary between 1.12-3.64 mg salingen 100 g dry soil -1 . It was also observed that extractable Zn content of soil samples (r = - 0.97**) had negative effect on ß-glucosidase activity, wheras total exchangable acidic cations (r = 0.70*) affected the activity positively. Catalase enzyme activities of soils changed between 5.25 - 9.00 mg O2 5 g dry soil -1 . Significant correlations were found between catalase activities and fraction of soils and extractable Fe content. Positive correlations, however, were determined between catalase activities and clay fraction (r = 0.82*) and salt content (r = 0.83**) of samples

Vergleich der salzstresstoleranz vielversprechender türkischer Winterkürbis- (Cucurbita maxima Duch.) und kürbis (Cucurbita moschata Duch.)-linien sowie interspezifischer hybriden

The objective of this study was to evaluate several selected Cucurbita genotypes for their salt resistance in a rootstock breeding program for grafted watermelon seedling production. Specifically, changes in the relative water content (RWC), leaf area (LA), total chlorophyll content (TCC) and proline concentration (PC) of a commercial cultivar (G32 code), two promising winter squash (G12 and G13 of Cucurbita maxima Duch.) lines, six pumpkin (G3, G27, G28, G29, G30 and G31 of Cucurbita moschata Duch.) lines, and four C. maxima × C. mochata hybrids (G14, G15, G40 and G42), were investigated with a control treatment and four levels of salt stress (4, 8, 12 and 16 dS/m). In this study, Cucurbita cultivars which showed significant differences according to RWC, LA, TCC and PC at least significant difference (LSD) tests (P < 0.05) and had salinity sensitivity index (SSI) value lower than 20%, were assessed as salt tolerant genotypes. The salt tolerant genotypes were grouped with principal component analysis (PCA) in each salt level. At the end of the study, all genotypes for all characteristics were generally tolerant at 4 dS/m salinity level. The G3, G12, G13, G14, G29 and G42 genotypes were resistant at 8 dS/m salinity, while the G15, G31, G32 and G40 were the most resistant genotypes at 12 and 16 dS/m. In conclusion, the selection of more salt resistant cultivars in rootstock breeding programs should be a priority to maintain growth performance in saline environments