Doğanay Tolunay
Istanbul University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Doğanay Tolunay.
Environmental Science & Technology | 2015
Mustafa Odabasi; Ezgi Ozgunerge Falay; Gizem Tuna; Hasan Altiok; Melik Kara; Yetkin Dumanoglu; Abdurrahman Bayram; Doğanay Tolunay; Tolga Elbir
Several persistent organic pollutants (POPs) like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ethers (PBDEs) were measured in needle, branch, bark, and tree ring samples in pine samples collected at 27 sites (21 industrial, 6 background) in Aliaga industrial region in Turkey. Soil, litter, and air samples were also collected to investigate the relationships between the air and soil, litter, and tree components. Concentrations decreased with distance from the sources and the lowest ones were measured at background sites. The spatial distribution of POPs indicated that the major sources in the region are the iron-steel, ship-breaking, petrochemical plants and the petroleum refinery. Significant correlations between the air concentrations and, soil, litter, and tree components indicated the interaction of these compartments with air. Observed increasing trends of POPs in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. These results indicated that tree components, litter and soil could be used to determine the spatial variations while tree rings could be used to investigate the historical trends of atmospheric POPs in a region. POP amounts (mg/ha) stored in different tree components, litter, and soil were also inventoried. Among the tree components, generally, the highest amounts were stored in the stem followed by needles. For the overall inventory, the highest amounts were stored in soil for PCNs, PBDEs, and PCBs while highest PAH amounts were stored in trees, indicating that in addition to soil, vegetation is also an important reservoir for POPs.
Scandinavian Journal of Forest Research | 2009
Doğanay Tolunay
Abstract This study examines the carbon concentrations of various above-ground biomass components (stem, bark, living branch, dead branch, needle and above-ground biomass), the forest floor and understorey. The research was carried out on Scots pine (Pinus sylvestris L.) stands in north-western Turkey. Sample trees were cut, and forest floor and understorey samples were collected from the 13 sampling areas in the 31-year-old Scots pine stands. Carbon contents of these samples were determined. Carbon concentrations of all tree components were found to be higher than 50%. This value is referred to as the general carbon conversion factor (CF). The weighted mean carbon concentration was found to be 51.96%. Consequently, if the CF for a single tree is taken to be 50%, carbon storage in the above-ground parts of the tree would have been underestimated by 3.77%. Carbon concentration, which was 53.02% in needles, was reduced to 50.08% in the litter plus fermentation layer of the forest floor and to 40.08% in the humus layer owing to decomposition. In the understorey, carbon concentration was determined to be 47.64%. There was a significant difference between the carbon concentrations of the tree components, forest floor and understorey.
Science of The Total Environment | 2014
Yagmur Meltem Aydin; Baris Yaman; Husnu Koca; Okan Dasdemir; Melik Kara; Hasan Altiok; Yetkin Dumanoglu; Abdurrahman Bayram; Doğanay Tolunay; Mustafa Odabasi; Tolga Elbir
Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO2) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m(2)s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/gh was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/gh. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and beta-myrcene were generally emitted by coniferous species. Oxygenated compounds were the third most prominent BVOC group and sesquiterpenes had slightly lower contributions.
Science of The Total Environment | 2016
Mustafa Odabasi; Doğanay Tolunay; Melik Kara; Ezgi Ozgunerge Falay; Gizem Tuna; Hasan Altiok; Yetkin Dumanoglu; Abdurrahman Bayram; Tolga Elbir
Several trace and macro elements (n=48) were measured in pine needle, branch, bark, tree ring, litter, and soil samples collected at 27 sites (21 industrial, 6 background) to investigate their spatial and historical variation in Aliaga industrial region in Turkey. Concentrations generally decreased with distance from the sources and the lowest ones were measured at background sites far from major sources. Spatial distribution of anthropogenic trace elements indicated that their major sources in the region are the iron-steel plants, ship-breaking activities and the petroleum refinery. Patterns of 40 elements that were detected in most of the samples were also evaluated to assess their suitability for investigation of historical variations. Observed increasing trends of several trace and macro elements (As, Cr, Fe, Mo, Ni, V, Cu, Pb, Sb, Sn, and Hg) in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. It was shown that lanthanides (La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb) could also be used for the investigation of historical variations due to specific industrial emissions (i.e., petroleum refining). Results of the present study showed that tree components, litter, and soil could be used to determine the spatial variations of atmospheric pollution in a region while tree rings could be used to assess the historical variations.
International Journal of Phytoremediation | 2015
Gülriz Bayçu; Doğanay Tolunay; Hakan Özden; István Csatári; S. Karadag; T. Agba; Sven Erik Rognes
Mining is an important source of metal pollution in the environment and abandoned mines are extremely restricted habitats for plants. Some plant species growing on metalliferous soils around mine tailings and spoil-heaps are metal-tolerant and accumulate high concentrations of metals. In this investigation, we aimed to perform a research in the CMC-abandoned copper mining area in Lefke-North Cyprus to assess the recent metal pollution in soil and plant systems. We collected 16 soil samples and 25 plant species from 8 localities around the vicinity of tailing ponds. Some concentrations of metals in soil samples varied from 185 to 1023 mg kg−1 Cu, 15.2 to 59.2 mg kg−1 Ni, 2.3 to 73.6 mg kg−1 Cd and metals for plants ranged from 0.135 to 283 mg kg−1 Cu, 0.26 to 31.2 mg kg−1 Ni, 0.143 to 277 mg kg−1 Cd. Atriplex semibaccata, Acacia cyanophylla, Erodium spp., Inula viscosa, Juncus sp., Oxalis pes-caprea, Pistacia lentiscus, Senecio vulgaris and Tragopogon sinuatus accumulated higher concentrations. BCF for Atriplex semibaccata was found very high, for this reason this plant can tentatively be considered as a hyperaccumulator of Cu and Cd, but it needs further investigation for its potential in phytoremediation.
Water, Air, & Soil Pollution: Focus | 2003
Doğanay Tolunay
Annual ring widths of forest trees are affected from different ecologicalfactors (e.g. climate, soil, etc.) and also from air pollution. In the areas with intensive air pollution annual ring width reductions are observed. For this reason, some methods which detect the annual ring widths, in other words, the increase or decrease in diameter increments, are used to examine air pollution. Industrial establishments found in the northern part of Izmir city (Aliaga region) affect air quality of this area negatively. In this investigation, annual ring widths of 13 Pinus brutia Ten. (Calabrian pine) and 20 Pinus nigra Arnold. (Austrian pine) from 4 mountains (Karabelen, Manisa, Kemalpasa, and Yamanlar) with different altitudes and exposures around Izmir city were detected and the effects of air pollution on these trees were determined. Intensive effects of air pollution have started in 1985, for that reason, annual ring widths were examined through a reference period before this year and a study period (1985–1998) after this year and results are statistically evaluated. Annual ring widths of tree samples in the northern exposure were affected from air pollution, and some reductions were observed. These reductions increased when there is a long drought period.
Annals of Forest Science | 2016
Jongyeol Lee; Doğanay Tolunay; Ender Makineci; Aydin Comez; Yeong Mo Son; Raehyun Kim; Yowhan Son
Abstract• Key messageSimulated and observed carbon stocks in Scots pine forests varied considerably with stand age. The contribution of biomass to the total forest carbon stocks increased and that of dead organic matter decreased with increasing stand age.• Context Understanding changes in forest carbon stocks over time is important to estimate carbon inventory. Although Scots pine (Pinus sylvestris L.) is a main species in Turkey, studies on such changes are still lacking.• Aims We aimed to estimate the changes in carbon stocks, with stand age, of Scots pine stands in Turkey using field work data and a forest carbon model (FBDC model).• Methods Biomass and dead organic matter carbon stocks were investigated to adjust the forest carbon model and to verify the model estimates. Forest carbon stocks with regards to stand age were simulated.• Results The simulated carbon stocks were generally in clear agreement with the observed values on a stand scale. Changes in simulated and observed carbon stocks of biomass and dead organic matter varied with stand age. The contribution of biomass to total forest carbon stocks increased, and that of dead organic matter decreased, with increasing stand age.• Conclusion We found that the carbon stocks in each pool and their contribution to the total forest carbon stocks varied with stand age. Our results are expected to contribute to the understanding of annual changes in the carbon stocks of Turkish forests.
Archive | 2017
Sabit Erşahin; Selim Kapur; Gönül Aydin; Erhan Akça; Doğanay Tolunay; Özden Görücü; Gülay Karahan; Bayram C. Bilgili
Recent increases in atmospheric CO2 concentration and increased climate variations enforced us to improve our understanding of the terrestrial biosphere to improve human-ecosystem harmony in regard with processes and feedbacks that have functions in the earth system as a whole. Terrestrial ecosystems are principal components of the main carbon pools and land use has a decisive impact on these pools. Studies showed that converting forest and grasslands to farmlands and urban areas can result in considerable amount of carbon losses to atmosphere. However, emitted amounts may depend on the geographical region as well as type of vegetation cover of the converted areas. Recent studies showed that feedbacks between climate change and vegetation is more complicated than it was thought. Combined with these feedbacks, the land use changes may have an intricate impact on carbon exchange between atmosphere and biosphere. Studies showed that the consequences of changes in land use are beyond the expected in terms of ecosystem functioning and environmental quality. Complex interactions among climate, soil, plant productivity, and land management should be understood well to balance ecosystem functions and human welfare. In this literature review, we discussed interactions and feedbacks among terrestrial ecosystems and global carbon balance in regard with global climate change.
Science of The Total Environment | 2018
Jongyeol Lee; Ender Makineci; Doğanay Tolunay; Yowhan Son
A significant area of the oak forests in Turkey has been historically managed by short-rotation coppicing for wood production. Coppice management was almost abandoned in Turkey in 2006 and so investigating its impact on forest carbon (C) sequestration has become an important issue. Therefore, we investigated the net effect of this change in management on C sequestration by oak forests in Turkey using field measurement data and a forest C model (Forest Biomass and Dead organic matter Carbon (FBDC) model). The FBDC model estimated the annual forest C dynamics and considered the effect of the substitution of wood for fossil fuels under two management scenarios over a 100-year period: (1) abandoning coppice (no management) and (2) continuing coppice (20-year-interval harvest). The field measurement data were used to parameterize the FBDC model to the study sites and to verify the simulated C stocks. Continuing coppice management constrained an increase in the C stocks (116.0-140.3 Mg C ha-1) and showed a mean annual C sequestration of 0.6 Mg C ha-1 yr-1 if wood was substituted for fossil fuels. In contrast, abandoning coppicing practices increased the level of forest C stocks (128.1-236.2 Mg C ha-1), enhancing the mean annual C sequestration to 1.1 Mg C ha-1 yr-1. Accordingly, the abandonment of coppice management increased the mean annual C sequestration by 0.5 Mg C ha-1 yr-1 in the long-term. However, sensitivity analysis showed a possibility of a larger difference in C sequestration between the two scenarios due to a decrease in the stand productivity by repeated coppices and a high likelihood of a lower substitution effect. The verification supported the scientific reliability of the simulation results. Our study can provide a scientific basis for enhancing C sequestration in coppice forests.
Journal of the Faculty of Forestry Istanbul University | 1999
Doğanay Tolunay
Arazi kullanimi ve toprak koruma kanunu tasari taslaginin ormancilikla ilgili maddelerinin ekolojik acidan irdelenmesi