Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Seasonal Changes of Soil Arthropods in Beech and Oak Ecosystems and Their

Effects on Litter Decomposition
The decomposition of plant litter is influenced by their chemical composition, the physical-chemical environment, and the decomposer organisms. Most studies interested in single species of decomposition have focused on substrate quality and climate effects on decomposition, and have excluded explicit recognition of the soil organisms involved in the process. Arthropods of the litter and soil play a critical role in the process of decomposition. They respond quickly to changes in climate and physico-chemical properties of soil. Acarina and collembola represent the bulk, about 90 to 95% of the total arthropod fauna of soil. Microarthropods, one of the several agents involved in litter decomposition are important in breaking down the plant litter
Plant litter decomposition is a key process in carbon and nutrient cycling. Rates of decomposition, and micro- and macroarthropods abundance and diversity associated with single-species and mixed-species litters were studied in an oak–beech ecosystems. The critical role of soil-faunal community composition in decomposition has been demonstrated using different mesh size litterbags to control exposure of litter to different faunal size classes. We placed litterbags of three mesh sizes across model grassland miniecosystems manipulated to enable communities containing 1) microfauna; 2) micro- and meso-fauna; 3) micro-, meso- and macro-fauna. All communities contained bacteria and fungi.
Totally 324 litterbags were randomly placed beneath the vegetation canopy, in contact with the litter layer. Three bags of each mesh size were removed per monthly. Monthly sampling of macroarthropods was conducted in nine replicates via pitfall trap and microarthropods was conducted in three replicates via steel soil corers. Soil fauna samples were extracted with modified Berlese-Tullgren funnel and they were stored in 70 % ethanol.
In this study, carried out between the years 2008-2009, amounts of leaf fall in oak, beech and oak-beech forested areas respectively were 325 g m^-², 320 g m^-² and 343 g m^-². Any important difference in terms of the decomposition among the micro, meso and macro-litterbags was not determinated. It was determined that the average decomposition was completed in oak areas in 4,6 years, in beech areas in 5,5 years, and in oak-beech areas in 5,4 years, the differences between them are nonsignificant. However, 27 taxa belonging to macroarthropods and 34 taxa belonging to microarthropods were determined and it was also identified that the community structure of the macroarthropods is mainly formed by predators while it is mainly formed by decomposers in the community structure of microarthropods. In Belgrade Forest conditions, the effects of arthropods on the decomposition were not as effective as fungi and bacteria.

ÇOBAN Süleyman

Tez Adı : Bolu-Ayıkaya Bölgesi Bitki Toplumları Ve Meşcere Kuruluş Özellikleri

Danışman : Prof. Dr. Gülen ÖZALP

Anabilim Dalı : Orman Mühendisliği

Programı : Silvikültür

Mezuniyet Yılı : 2013

Tez Savunma Jürisi : Prof. Dr. Gülen ÖZALP

Prof.Dr. Engin ÖZHATAY

Prof. Dr. H. Ferhat BOZKUŞ

Prof. Dr. Alper H. ÇOLAK

Prof. Dr. Erol KIRDAR