General Directorate of Forestry
General Directorate of Forestry
Ciftci A.,Middle East Technical University |
Karatay H.,Southeastern Anatolia Forest Research Institute |
Kucukosmanoglu F.,Poplar and Fast Growing Species Research Institute |
Karahan A.,General Directorate of Forestry |
Kaya Z.,Middle East Technical University
Tree Genetics and Genomes | Year: 2017
The European black poplar (Populus nigra L.) is an ecologically and economically important tree species for Turkey. The important and major genetic resources of species for future breeding and ex situ conservation purposes have been archived in a clone bank in Ankara by selecting clones from natural populations and old plantations throughout Turkey. There is no study to date assessing genetic composition these materials. Two-hundred-thirty-three P. nigra clones from six geographic region of Turkey (clone collection populations), and 32 trees from two natural populations (Tunceli and Melet) were genotyped by using 12 nuclear microsatellite DNA markers. There were nine clones which duplicated in various frequencies. The analysis carried out with removal of the duplicated clones revealed a moderately high genetic diversity in studied populations. The observed heterozygosities ranged from 0.59 in Tunceli natural to 0.69 in Central Anatolia clone collection populations. In general, there was excess of heterozygosity in the studied populations. Populations composed of clone collections were significantly differentiated from natural populations (FST = 0.17), while there was little differentiation among those populations in the clone collection (FST = 0.03). Two distantly located natural populations with small sizes also differed from each other (FST = 0.17). Genetic structure analysis revealed two distinct groups (clone collection vs natural populations) with very high membership values (>92%). Clone collection populations had high level of admixture while natural populations had homogenous genetic structure. The presence of large number of clonal duplication, reduced genetic differentiation, and high level of admixture in clone collection populations indicate that genetic resources of European black poplar were highly degraded through genetic erosion and pollution caused by intensive cultural practices and extensive dispersal of clonal materials. To understand genetic diversity and its structural pattern thoroughly in the six clone collection populations, a further study with extensive and systematic sampling of European black poplar populations in major river ecosystems in Turkey will be useful. © 2017, Springer-Verlag Berlin Heidelberg.
Bagci S.,General Directorate of Forestry |
Cayci G.,Ankara University |
Kutuk C.,Ankara University
Journal of Plant Nutrition | Year: 2011
This study was performed under greenhouse conditions, with coir dust, moss peat, and sedge peat as the main components of the growing media. The performance of the media was evaluated through the growth of the primula (Primula obconica) plant. In general, aeration capacities were found to be relatively low, except for growing media that included moss peat mixtures. Nevertheless, easily available water content of all growing media was found to be within the appropriate ranges. Total and water-available plant nutrient contents of coir dust, moss peat, and sedge peat significantly fluctuated. Ornamental parameters related to media treatments were statistically significant, with respect to visual score performances, total leaf numbers, crown width, and total plant fresh weights. This study determined that coir dust, which is an industrial by-product, could be utilized for up to 50% of the total composition of coir dust-moss peat based media in floricultural aims. As floricultural quality parameters considered, 50% coir dust and 50% moss peat and 25% coir dust and 75% moss peat gave good results as much as 100% moss peat © Taylor & Francis Group.
Ozcelik R.,Suleyman Demirel University of Turkey |
Yavuz H.,Karadeniz Technical University |
Karatepe Y.,Suleyman Demirel University of Turkey |
GurlevIk N.,Suleyman Demirel University of Turkey |
Kiris R.,General Directorate of Forestry
Turkish Journal of Agriculture and Forestry | Year: 2014
Seven different nonlinear height (h)-diameter (d) models were developed and compared for brutian pine (Pinus brutia Ten.), black pine (Pinus nigra Arnold), and Taurus cedar (Cedrus libani A.Rich.) in southern Turkey. Residual analysis was conducted to identify the error structure. A weighting factor of wi =1/d was found to be appropriate for achieving the equal error variance assumption. The performance of the models was compared and evaluated based on 6 statistical criteria and residual analysis. Results suggested that the Gompertz model was superior to the other models in terms of its predictive ability. These tree species were located throughout the Mediterranean region, covering a wide range of topographic and climatic conditions. It is well known that height-diameter relationships depend heavily on local environmental conditions. Differences in the height-diameter relationship among and between ecoregions were tested using the nonlinear extra sum of squares method. Test results suggested that height-diameter models significantly differed between ecoregions, indicating that ecoregion-based height-diameter models are needed for prediction purposes. The ecoregion-based height-diameter models developed in this study may provide more accurate information for developing forest growth and yield models. © Tübïtak.
Bettinger P.,University of Georgia |
Demirci M.,General Directorate of Forestry |
Boston K.,Oregon State University
Silva Fennica | Year: 2015
The use of a reversion technique during the search process of s-metaheuristics has received little attention with respect to forest management and planning problems. Reversion involves the inter-ruption of the sequence of events that are used to explore the solution space and the re-initiation of the search process from a high-quality, known starting point. We explored four reversion rates when applied to three different types of s-metaheuristics that have previously shown promise for the forest planning problem explored, threshold accepting, tabu search, and the raindrop method. For two of the s-metaheuristics, we also explored three types of decision choices, a change to the harvest timing of a single management unit (1-opt move), the swapping of two management unit’s harvest timing (2-opt moves), and the swapping of three management unit’s harvest timing (3-opt moves). One hundred independent forest plans were developed for each of the metaheuristic/reversion rate combinations, all beginning with randomly-generated feasible starting solutions. We found that (a) reversion does improve the quality of the solutions generated, and (b) the rate of reversion is an important factor that can affect solution quality. © 2015, Silva Fennica. All rights reserved.
Demirci M.,General Directorate of Forestry |
Bettinger P.,University of Georgia
Forest Policy and Economics | Year: 2015
Sustainable forest management is a key to maintaining the economic, social, environmental and cultural benefits and services of forests for the long term. In Turkey, all forestry activities, such as regeneration and stand tending, are carried out according to forest management plans, which are used as a tool for achieving sustainable forest management goals. An intermediate yield harvest plan, which is a part of management plan, is used for stand tending. Every year, the compartments (stands) within the same stand tending block are thinned. Decision support systems have not been used so far in order to designate the size and location of these stand tending blocks. In this study, we used multi-objective goal programming to designate stand tending blocks for an entire decade. We developed two models: a linear goal programming model and a nonlinear goal programming model. To design these models, we only considered wood flow and distance between the centroids of compartments as the objectives. Then, we used a working circle of the Golcuk forest sub-district, which is a planning unit in Turkey, as a case study. The linear model worked very well, and for reference scenarios, the deviation in volume scheduled for the entire decade was only 16.8m3 and the deviation in total distance between compartments was 172km. Scenario 3, with weights of 0.2 for distance and 0.8 for volume, produced the best results. The nonlinear model, which in theory would better represent the problem, was not as useful due to a combination of the time required to produce a solution and the quality of the solutions. The linear model can be developed by including other factors and used by forest planners. © 2015 Elsevier B.V.
Tolunay D.,Istanbul University |
Karabiyik B.,General Directorate of Forestry |
Temerit A.,General Directorate of Forestry
IForest | Year: 2011
Monitoring of forest condition in Turkey started in 2006 when a 16x16 km grid of Level I plots was established. In 2007, the first 48 Pinus brutia plots were surveyed for crown condition. In 2008 and 2009, the plots were 398 and 563, respectively. In 2007, the mean defoliation for P. brutia was 13.0 %. In 2008-2009, the mean defoliation was 19.5-19.8 % and 27.0-23.0 % for coniferous and broadleaved species, respectively. Defoliation was higher than 25 % on 24.6-18.7 % of the monitored trees. The species with the highest defoliation were Carpinus betulus and Juniperus foetidissima in 2008, and Quercus pubescens and Juniperus communis in 2009. The slight improvement in forest health in 2009 may be attributed to better weather conditions than in 2008 (higher precipitation). The forests along the Black Sea coast of Thrace showed the highest defoliation in both 2008 and 2009. This may be due to transboundary air pollution from Istanbul, where sources of sulphate and nitrate pollution occur. Elevated defoliation rates were also observed in the Black Sea region; they were most probably caused by biotic factors in plots subject to industrial pollution. © iForest - Biogeosciences and Forestry.