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Gulcu S.,Suleyman Demirel University of Turkey | Cemal Gultekin H.,Poplar and Fast Growing Forest Trees Research Institute | Olmez Z.,Artvin Coruh University
African Journal of Biotechnology | Year: 2010

The aim of this study is to determine the appropriate sowing time and depth in spring for Taurus Cedar (Cedrus libani A. Rich) in Turkey. The effects of sowing time and depth were determined with regard to the germination rate of seedlings' quality. The seeds were collected from Kapidag-Isparta, in Turkey, in 2003 and 2004. The seeds were sown at 6 different dates and 5 different depths under natural conditions without any pre-treatment in 2004 and 2005. The statistical approach was randomized block design with 3 replications and 100 seeds were sown for each replication. The 1000 seed weights and germination percentages of the seeds were determined under laboratory conditions before sowing in the nursery. According to analysis of variance and Duncan's test, in locations with appropriate soil conditions, seeds should be sown at 5 mm depth as soon as possible until the second half of February. The germination of 65% can be obtained from seeds sown under these conditions. High quality, bare root and one-year-old seedlings can be grown from approximately 55% of the seeds. Moreover, spring sowing should not take place after March 15th and at depths of more than 20 mm. © 2010 Academic Journals. Source


Gulcu S.,Suleyman Demirel University of Turkey | Gultekin H.C.,Poplar and Fast Growing Forest Trees Research Institute | Celik S.,Isparta Regional Forest Directorate | Eser Y.,Suleyman Demirel University of Turkey | Gurlevik N.,Suleyman Demirel University of Turkey
African Journal of Biotechnology | Year: 2010

The aim of this study was to determine appropriate pot length and growing medium for Crimean Juniper seedlings (Juniperus excelsa Bieb.), which will be used for afforestation of extreme areas. For this purpose, polyethylene pots of 11 cm width and 20, 25 and 30 cm lengths were used. As growing medium, 13 different treatments were used, containing different ratios of forest soil, pumice, creek sand and humus collected from the species' natural forest environments. The experimental design was a randomized block with 3 replications under open field conditions. Some morphological properties of the seedlings, such as seedling height, root collar diameter, shoot and root fresh and dry weights and shoot/root ratios (fresh and dry weights) were measured on 1 + 0 year old seedlings. Statistical analyses indicated that when pot length increased, the seedling quality improved. The seedlings with the best quality in terms of the measured criteria can be grown in 11 cm x 30 cm pots. In respect to the growing media, 70% forest soil + 15% humus + 15% pumice or creek sand should be used. © 2010 Academic Journals. Source


Yurtseven I.,Istanbul University | Zengin M.,Poplar and Fast Growing Forest Trees Research Institute
Annals of Forest Research | Year: 2013

The objective of this study is to reveal whether it is possible to predict rainfall, throughfall and stemflow in forest ecosystems with less effort, using several measurements of rainfall interception (hereafter 'interception') and an artificial neural network based linear regression model (ANN model). To this end, the Kerpe Research Forest in the province of Kocaeli, which houses stands of mixed deciduous-broadleaf forest (Castanea sativa Mill., Fagus orientalis Lipsky, Quercus spp.), black pine (Pinus nigra Arnold), maritime pine (Pinus pinaster Aiton) and Monterey pine (Pinus radiata D. Don), was selected study site. Four different forest stands were observed for a period of two years, during which rainfall, throughfall and stemflow measurements were conducted. These measurements were separately calculated for each individual stand, based on interception values and the use of stemflow data in strict accordance with the rainfall data, and the measured throughfall interception values were compared with values estimated by the ANN model. In this comparison, 70% of the total data was used for testing, and 30% was used for estimation and performance evaluation. No significant differences were found between values predicted with the help of the model and the measured values. In other words, interception values predicted by the ANN models were parallel with the measured values. In this study, the most success was achieved with the models of the Monterey pine stand (r2 = 0.9968; Mean Squared Error MSE = 0.16) and the mixed deciduous forest stand (r2 = 0.9964; MSE = 0.08), followed by models of the maritime pine stand (r2 = 0.9405; MSE = 1.27) and the black pine stand (r2 = 0.843, MSE = 17.36). Source


Kayacan B.,Duzce University | Ucal M.S.,Kadir Has University | Ozturk A.,Artvin Coruh University | Kocer S.,Poplar and Fast Growing Forest Trees Research Institute
Journal of Food, Agriculture and Environment | Year: 2012

A primary econometric approach is presented to understand the determinants of variation in national demand for domestically-produced fuelwood in Turkey. Also included in this study is a demand forecast for fuelwood based upon the econometric model proposed in this study. Being in multiplicative form originally, the proposed model is converted in to a double-log or log-linear form, for the ease of immediate interpretation of the parameter estimates in respect of elasticities. Parameter estimation is based on a panel and time series data set that belongs to the 15-year period between 1995 and 2009. The demand forecast presented has a horizon of 7 years beyond 2009. Major findings of the research include: 1) fuelwood demand in Turkey appears to conform to the law of demand with an inverse price-demand relationship; 2) fuelwood demand is notably pricesensitive with relatively high price elasticity; 3) fuelwood does not appear to be a related (complementary or substitute) good with coal and natural gas; and 4) fuelwood in Turkey is likely to be a "normal good" in respect of demand-income relationship. Meanwhile, based upon the proposed model here, fuelwood demand in Turkey may reasonably continue to show a downward trend till a level of 5 million m3 per annum, which is an about 50% reduction from the demand level in 1995. Further research is particularly needed for Turkey in view of the rapidly changing socio-economic profile of rural and urban population, which is being reflected in the demand for energy from wood in forms besides wood in the raw. Source


Kayacan B.,Duzce University | Ucal M.S.,Kadir Has University | Ozturk A.,Artvin Coruh University | Bali R.,General Directorate of Forests | And 2 more authors.
Journal of Food, Agriculture and Environment | Year: 2012

This study is a primary econometric analysis to explore the factors explaining the changes in industrial roundwood demand in Turkey. The study also includes demand forecasts based on the econometric models proposed herein. We constructed two separate econometric models: one for national demand for domestically-produced sawlog, and the other for national demand for domestically-produced non-sawlog industrial roundwood. Models were originally designed in multiplicative form. The original models are then converted into the log-linear form so that the relevant coefficients of the regression equations would immediately reflect the elasticities. Estimation of the model parameters are based on a panel data set of fifteen years (1995-2009) by twenty seven regional forest directorates in the country. In accordance with the maxim of less than the half of the 15 years period of data set, the demand forecasts are made for seven years beyond 2009. In view of the results, the explanatory power of the proposed models can arguably be deemed satisfactory especially considering the lack of earlier studies of this scale and scope. This consequently increases the credibility of the demand projections. Notwithstanding signs of the estimated parameters of the models are for the most part congruent with those expected in light of the economic theory and practice, some intriguing results are obtained. Perhaps most notably, while the sign of the estimated price elasticity of sawlog demand occurred unexpectedly positive, the variation in sawlog demand is explained to a considerable extent by the variation in the price of imported sawlog, hence an expected cross elasticity. Also notable is that the price of imported "fuelwood" holds a positive relationship with the national demand for domestic non-sawlog imdustrial roundwood, which is an expected cross elasticity since virtually all of the imported "fuelwood" is used as raw material for industry (e.g. chip and fiberboard industry). Finally, both models suggest overall boost in demand; yet an upper bound of 4.5 million m 3 for national demand for domestically-produced sawlog, and of 15 million m 3 for national demand for domestically-produced non- sawlog industrial roundwood can be expected by 2016. Source

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