Browsing by Author "Kravkaz I.S."

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Botany of Crocus ancyrensis through domestication
(2010-01-31) Kravkaz I.S.; Vurdu H.
Crocus ancyrensis (Herbert) Maw is an endemic species and widely distributed in the Central Anatolia and the Western Black Sea region of Turkey. The species is under threat of heavy grazing, uncontrolled gathering, recreational pressure and many different kinds of land disturbances. The aim of this study is to examine the phenology, morphology and seed formation of this species in its natural habitat in Kastamonu area. The observation and the measurements have been made at three locations. C. ancyrensis is a yellow colored spring flowering species. Leaf initiation starts in just a couple of days before or with flowering. Flowering time is between the second half of February and the first half of March. The lifespan of the flower is about 15 days depending on climate. The capsule can be seen in mid April above the soil and seed maturation is at the end of May which is about 45 days after flower disappearance. The leaves dry and disappear in July. On the average, each capsule has 30 seeds and the one thousand seed weight is 3,52 g. The seed requires 10°C±2°C and 70% relative humidity for germination. As a result, there is a possibility to domesticate this species from its seeds in order to conserve or to make mass agricultural production for its further uses.
Effects of tree species, stand age and land-use change on soil carbon and nitrogen stock rates in northwestern Turkey
(2016-02-01) Sariyildiz T.; Savaci G.; Kravkaz I.S.
Effects of tree species, stand age and land-use change on soil carbon and nitrogen stock rates were investigated in the northwest of Turkey using 4 common tree species as black pine (Pinus nigra Arnold.), Scots pine (Pinus sylvestris L.), Oriental beech (Fagus orientalis Lipsky) and Uludag fir (Abies nordmanniana ssp. bornmuelleriana). Three tree species (black pine, Scots pine and Oriental beech) were used to investigate the differences in soil C and N among tree species. Old and young Uludag fir stands and adjacent grassland were used to study the differences in soil C and N with stand age and land-use change. Mineral soil samples were taken from 0-10 cm and 10-20 cm soil depths, and analyzed for pH, soil texture, bulk density, total soil carbon and total nitrogen. The total soil carbon and total nitrogen pools were then calculated by multiplying soil volume, soil bulk density, and the total soil carbon or total nitrogen content. Results showed significant differences in soil carbon and nitrogen contents, carbon/nitrogen ratios and stock rates among the three species, and between old and young fir stands and grassland. In general, when 0-20 cm soil depth was considered, mean soil carbon stock rate was the highest under black pine (79 Mg C ha-1) followed by Scots pine (73 Mg C ha-1) and beech (67 Mg C ha-1), whereas mean soil nitrogen stock rate was the highest under beech (9.57 Mg N ha-1) followed by Scots pine (5.77 Mg N ha-1) and black pine (4.20 Mg N ha-1). Young fir stands showed lower soil carbon stock, but higher soil nitrogen stock rates compared to old fir stands and grassland. Our results demonstrated that tree species, stand tree age and land-use change can have significant effects on soil carbon and nitrogen content and stocks rates. These findings can help to enhance forest management activities, such as selection of tree species for carbon sequestration in plantation systems, design of sustainable agroforestry systems, and improvement of biogeochemical models.