A New Paleoecological Assessment of Southwest Anatolia: Late Holocene Paleovejetation Changes and Relationships with Lake Karataş and its Surroundings
This study was carried out in Lake Karataş which is located at the site of Burdur Depression in the southwestern Anatolia (Tefenni Plain). The main aim of the study is to determine the changes of paleovegetation and the factors that effect these changes from ̴2000 cal. BP years ago to Lake Karataş and its surroundings. For this purpose, fossil pollen analysis methods were applied on sediment core with a total length of 255 cm. The data obtained were diagrammed in the Tilia 2. 0. 41 program. Pinus sp., Juniperus sp. and Quercus sp. (evergreen) in arboreal pollen (AP) and Chenopodiaceae, Asteraceae, Lactuaceae and Poaceae in nonarboreal pollen (NAP) are important species that forming the vegetation. The temporal changes of these species reveal the local vegetation structure which is effective around the lake. Generally Abies sp., Cedrus libani and Quercus sp. (evergreen) indicate that 1460-1150 cal. BP, 840-680 cal. BP and 680-480 cal. BP are cold periods. In the whole diagram, the peak period of human impact was determined as 840-30 cal. BP. Olea europaea, Vitis sp. Fraxinus sp. in AP and Polygonum aviculare, Plantago lanceolata, Centaurea solstitialis in NAP corresponds to the peak period in the diagram. As a result, depending on the methods of analysis of fossil pollen, as a result of climate change and human impact, the variety of individual plant species constituting the paleovegetation structure and forest progression / regression were evaluated.
Güneybatı Anadolu’dan Yeni Bir Paleoekolojik Değerlendirme: Karataş Gölü ve Çevresinin Geç Holosen Paleovejetasyon Değişimleri ve İklim ile İlişkileri
Bu çalışma, Güneybatı Anadolu’da Burdur Depresyonu’nun güneybatısında (Tefenni Ovası) yer alan Karataş Gölü’nde yapılmıştır. Çalışmanın temel amacı, Karataş Gölü ve çevresinin ̴2000 yıl öncesinden günümüze paleovejetasyon değişimini ve bu değişimler üzerinde etkili olan faktörleri belirlemektir. Bu amaç doğrultusunda Karataş Gölü’den temin edilen toplam uzunluğu 255 cm (GÖ 1890 kal. 14C) olan sediman karotu üzerinde fosil polen analizleri gerçekleştirilmiş ve elde edilen veriler Tilia 2.0.41 programında diyagram haline getirilmiştir. Fosil polen diyagramına göre arboreal polen (AP) içerisinde Pinus sp., Juniperus sp. ve Quercus sp. (evergreen), nonarboreal polen (NAP) içerisinde ise Chenopodiaceae, Asteraceae, Lactuaceae ve Poaceae önemli türler olmuştur. Bu türlerin zamansal olarak değişimleri göl çevresinde etkili olan yerel vejetasyon yapısını ortaya koymaktadır. Genel olarak kalibre (kal.) GÖ 1460-1150, kal. GÖ 840-680, kal. GÖ 680-480 arasında Abies sp., ve Cedrus libani soğuk dönemler olduğunu göstermektedir. Tüm diyagram içerisinde insan etkilerinin en yoğun olduğu dönem kal. GÖ 840-30 olarak belirlenmiştir. AP içerisinde Olea europaea, Vitis sp., Fraxinus sp.; NAP içerisinde ise Polygonum aviculare, Plantago lanceolata, Centaurea solstitialis’in diyagramda en yoğun olduğu dönemdir. Sonuç olarak, fosil polen analiz metotlarına bağlı olarak, iklim değişikliği ve insan etkisi sonucunda paleovejetasyon yapısını oluşturan bireysel bitki türleri çeşitliliği ve orman ilerlemesi/gerilemesi kapsamında değerlendirilmiştir.
This study was carried out in Lake Karataş which is located at the site of Burdur Depression in the southwestern Anatolia (Tefenni Plain). The main aim of the study was to determine the last ~2000 cal. BP years of paleovegetation change and the factors that affecting this changes at Lake Karataş and its surroundings. For this aim, drilling was performed from the most convenient point where depth of water and sediman accumulation is sufficient with no flow and contaminete in Lake Karataş. As a result of the field work, sediment core which is total length of 255 cm was obtained. Fossil pollen analysis methods were applied on a total of 34 samples with nearly 8 cm interval on the sediment core. The data obtained from pollen analysis were identified in the light microscope. The data obtained were diagrammed in Tilia 2.0.41 program. The samples taken from 138 cm and 253 cm on the sediment core of Lake Karataş were dated. According to the results of 14C aging analysis, 1384 ± 25 BP and 254 cm and 1922 ± 27 BP years of age were obtained. Depending on the changes occurring on the diagram are divided 2 main zones and 6 subzones. KTG 18 Zone 1 covers 882-1889 cal. BP and KTG Zone 2 comprise 5-882 cal. BP. During the Hot Climate Period of Rome, 1400 Cold Climate Period, Medieval Hot Climate Period and Little Ice Age Climate Period changes in the paleovegetation structure of Lake Karataş and its vicinity were determined. Pinus sp., Juniperus sp. and Quercus (evergreen) sp.’ in AP (arboreal pollen) and Chenopodiaceae, Asteraceae, Lactuaceae and Poaceae in NAP (nonarboreal pollen) are important species that forming the vegetation structure. The temporal changes of these species reveal the local vegetation structure which is effective around the lake. In Zone 1, the AP ratio was 61.6 % in 1885 cal BP and 78.9 % in 915 cal. BP at the end of the zone. One of the important points in this zone is that Fraxinus sp. reached its highest level with 15 % in 1850 cal. BP. The most represented species in herbaceous vegetation are Chenopodiaceae, Lactuaceae and Asteraceae. AP ratio in zone 2 was 76.6 % in 840 BP and 83.2 % at the end of zone. In the AP, Olea europaea, Vitis sp., Fraxinus sp. and in NAP, Polygonum aviculare, Plantago lanceolata, Centaurea solstitialis that peaked in the diagram (840-30 BP) corresponds to the highest human impact period. Between 2000 and 1400 cal. BP, when in the Hot Climate Period of Rome which is characterized by the increase of evaporation and drought in the Eastern Mediterranean, the rate of decrease in NAP is observed in the 1890s cal. BP. The presence of the Cedrus libani and Quercus sp. (evergreen) showing the humid climatic condition was increased between 1340 and1145 cal. BP in the 1400 Cold Climate Period (1450-1050 cal. BP), where there is a transition towards to cooler, humid and variable climatic conditions in Europe. The dominance of Chenopodiaceae, Asteraceae and Lactuaceae in NAP reflects the local vegetation of Lake Karataş and its surroundings. Increased solar radiation causes The Archaic Oscillation index to reached positive values in the Medieval Warm Climate Period (1050-650 cal. BP) which is characterized by an increase in temperatures, the ratio of Quercus sp. (evergreen)and Cedrus libani showed increase. While Chenopodiaceae showed a decrease Poaceae, Asteraceae and Artemisia sp. ratios showed a steady increasing trend that the local vegetation had found a distribution area around the lake. The existence of Polygonum aviculare, Plantago lanceolata and Centaurea solstitialis which indicate grazing activities and the existence of Olea europaea, Juglans sp, Brassicaceae and Cerealia type which indicate agricultural activities are important evidence of human impact around the lake. Between 650 and 100 cal. BP, when Little Ice Age Climate Period Eastern Mediterranean was more humid and cold weather conditions. The increase in Abies sp, Cedrus libani and Quercus sp. (evergreen) at the Spörer Minimum Period and the Maunder Minimum Period indicates the presence of the cold period. Chenopodiaceae, Lactuaceae, Poaceae and Artemisia sp. formed dominant species in NAP. The total presence of Olea europaea, Vitis sp, Fraxinus sp. and Juglans sp at Little Ice Age corresponds to the highest agricultural production. Consequently, depending on the methods of fossil pollen analysis, climate change and human impact on paleovegetation were determined with in the scope of progression/regression in forest and changes in individual plant species diversity