44 research outputs found
Changements saisonniers et altitudinaux des concentrations foliaires en nutriments de Hedera helix L. (Araliaceae)
La résorption est l’une des plus importantes stratégies d’utilisation des nutriments développées par les plantes. Le ratio de la surface foliaire à la masse sèche (SLA) est lié aux nutriments foliaires. Dans la présente étude, les changements de concentration en SLA, N et P, le rapport N/P et la teneur en C des feuilles de lumière et d’ombre de la liane sempervirente Hedera helix L. ont été étudiés au long de l’année sur un gradient altitudinal. L’efficience (RE) et l’efficacité (RP) de la résorption foliaire ont également été calculées dans les feuilles de lumière et celles d’ombre. Les traits foliaires ont montré des changements significatifs entre les localités et au cours de l’année. Des différences significatives sont apparues entre les feuilles de lumière et celles d’ombre pour ce qui concerne le SLA, la concentration en N et la teneur en C, mais se sont avérées dépendantes des différences d’altitude. Toutefois, aucune différence significative de concentration en P n’a été trouvée entre les feuilles de lumière et celles d’ombre. Dans les feuilles, tant de lumière que d’ombre, le SLA augmentait à la fin du printemps et baissait après l’automne. D’une manière générale, la teneur en C augmentait en janvier. La concentration en N des feuilles, tant de lumière que d’ombre, était habituellement la plus faible en début d’été et croissait en octobre. Les plus fortes teneurs en P ont été observées entre décembre et janvier dans toutes les localités. N/P différait significativement selon les localités. L’interaction localité x temps était aussi significative sauf pour les concentrations en P foliaire et N/P. Des corrélations positives ont été notées entre les traits foliaires et ceux du sol comme le SLA, les N, P et C foliaires, l’humidité du sol, et les teneurs en N, P et C. La PRE (efficience de la résorption du phosphore) et la NRP (efficacité de la résorption de l’azote) différaient de manère significative entre les localités mais pas entre les feuilles de lumière ou d’ombre. Cependant, la NRE (efficience de la résorption de l’azote) et la PRP (efficacité de la résorption du phosphore) n’étaient pas significativement différentes. Les feuilles de lumière et celles d’ombre ont montré une resorption incomplète car, dans toutes les localités, les valeurs de NRP et de PRP étaient supérieures aux niveaux de référence.Nutrient resorption is one of the most important nutrient use strategies developed by plants. The ratio of leaf area to dry mass (SLA) is related to leaf nutrients. In this study, the changes in SLA, N, P concentrations, N/P ratio and C content of sun and shade leaves of the evergreen liana Hedera helix L. were investigated over the year in an altitudinal gradient. Foliar resorption efficiency (RE) and proficiency (RP) were also calculated in sun and shade leaves. Leaf traits significantly changed among studied localities and over the year. There were statistically significant differences between sun and shade leaves regarding SLA, N concentration and C content, but these were dependent on the differences of altitude. However, no significant differences were found for P concentrations between sun and shade leaves. SLA increased in sun and shade leaves at the end of the spring and decreased after the fall. Leaf C content generally increased in January. Leaf N concentration in sun and shade leaves was usually lowest in early summer and increased in October. The highest leaf P content was found between December and January in all localities. N/P significantly differed between localities. Locality × time interaction was also significant except leaf P concentrations and N/P. Positive correlations were seen between leaf and soil traits such as SLA, leaf N, P and C, soil moisture, N, P and C. PRE (Phosphorus resorption efficiency) and NRP (Nitrogen resorption proficiency) were significantly different among the localities, but not among sun and shade leaves. However, NRE (Nitrogen resorption efficiency) and PRP (Phosphorus resorption proficiency) were not significantly different. Sun and shade leaves of H. helix showed incomplete resorption, because, in all localities, NRP and PRP values were above the benchmark levels
Kocaeli’de evlerde, ofislerde ve okullarda iç ortam hava kalitesinin belirlenmesi
TÜBİTAK ÇAYDAG01.01.2008Bu çalışmada, Kocaeli’de farklı bölgelerde ve farklı mikroçevrelerde (ev, okul, ofis), iç ve dış ortamda yapılan örneklemeler ile aktif ve pasif örnekleme ve ölçüm teknikleri kullanılarak 2 farklı partikül fraksiyonunda (PM2.5 ve PM10) 16 ağır metal (Al, As, Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, S, Si, Ti, V ve Zn), uçucu organik bileşikler (UOB’ler), SO2, NO2 ve O3 konsantrasyonları belirlenmiştir. Ayrıca, iç ortamda ölçülen konsantrasyonlarla maruziyet arasındaki ilişkiyi kurabilmek için, kişisel örnekleyiciler kullanılarak kişisel maruziyet düzeyleri de belirlenmiştir. NO2 için İç Ortam/Dış Ortam konsantrasyon oranlarının evlerde her 2 mevsimde de okullar ve ofislere nazaran yüksek bulunması evlerin iç ortamlarında NO2 kirletici kaynaklarının ofis ve okullara oranla daha baskın olduğu göstermektedir. İç Ortam/Dış Ortam oranlarının 1’in çok altında bulunması O3 ve SO2’in dış ortam kaynaklı bir kirletici olduğunu ve iç ortamlarda önemli bir kaynağının bulunmadığını göstermektedir. PM2.5 fraksiyonundaki toprak kaynaklı elementlerin iç ve dış ortam konsantrasyonlarının yüksek düzeylerde bulunması bu elementlerin iç ortamlara taşınımının yüksek olduğunu göstermektedir. PM2.5 kişisel maruziyet düzeylerinin As, S, V, Cu ve Cr gibi yanma kaynaklı elementler için iç ortam maruziyet düzeylerinden 2–6 kat daha yüksek olması ve bazı mevsimsel farklılıklar bulunmasına rağmen İç Ortam/Dış Ortam oranlarının genellikle 0.3–0.7 aralığında bulunması gözlenen yüksek kişisel maruziyet düzeylerinde dış ortamların etkisini göstermektedir. PM10 partikül fraksiyonunda belirlenen ağır metallerin büyük bir bölümü için İç Ortam/Dış Ortam oranlarının 1’den küçük bulunması dış ortam kirletici kaynaklarının iç ortam kirletici kaynaklarına daha baskın olduğunu göstermektedir. En yüksek UOB kirlilik düzeylerine örneklenen kişilerde rastlanırken bunu iç ortam ve dış ortam UOB kirlilik düzeyleri takip etmiştir. Her 2 mevsimde de toluen ev, ofis ve okullardaki UOB kirlilik düzeylerine en çok katkıda bulunan bileşik olurken onu etilbenzen, m,p-ksilen, stiren, nonan, hegzan, benzen, o-ksilen ve heptan bileşikleri takip etmektedir. Kentsel alanlarda elde edilen toplam UOB konsantrasyonlarının endüstriyel alanlarda elde edilen değerlerle uyum içinde bulunmuştur. Trafiğin belirteci olan bileşikler (BTEX, 1,2,4-trimetilbenzen) kentsel alanlarda yüksek bulunurken petrokimyanın belirteci olan hexane ve heptane bileşikleri endüstrinin yoğun olduğu alanlarda yüksek bulunmuştur. Ayrıca kentsel ve endüstriyel alanlarda elde edilen UOB konsantrasyonlarının sanayii ve trafikten uzak alanlarda elde edilen konsantrasyonlardan yüksek olması trafik ve sanayiinin tesbit edilen UOBlere olan katkısının ne kadar yüksek olduğunu göstermektedir. İç ortam, dış ortam ve kişisel maruziyet kirlilik düzeylerine etki ederek hava kalitesine olumsuz yönde katkıda bulunan kirletici kaynakların belirlenmesi amacıyla Pozitif Matris Faktörizasyonu (PMF) reseptör modelleme tekniği kullanılmıştır. PMF modellemesi, korelasyon analizi, iç ortam/dış ortam oranları, mikroçevre karakteristikleri, anketler ve zaman aktivite çizelgeleri incelenen kirleticilerin en önemli emisyon kaynaklarının endüstri, trafik ve sigara kullanımı olduğunu göstermektedir. İç ortam, dış ortam ve kişisel maruziyet düzeylerinin dünyanın diğer bölgelerinde yapılan çalışmalarda raporlanan düzeyler ile kıyaslanabilir olduğu bulunmuştur. Kişisel maruziyet konsantrasyonları kullanılarak çalışmada incelenen inorganik ve organik kirleticilerden kaynaklanan sağlık riski değerlendirmesi yapılmıştır. Ev, ofis ve okullarda örneklenen kişiler için hesaplanan “Toplam Kanser Riski” ve “Toplam Tehlike İndeksi” değerleri hem ortalama konsantrasyonlar hem de en kötü senaryo göz önüne alınarak incelendiğinde en yüksek risk altında bulunan kişilerin ev hanımları olduğu bunları öğretmenler ve ofis çalışanlarının takip ettiği söylenebilir. Değerlendirme kentsel, endüstriyel, endüstri ve trafikten uzak alanlar için yapıldığında her 3 alanda da yaşayan kişilerin birbirine yakın ve yüksek kanser riski taşıdıkları söylenebilir. Aynı değerlendirme sigara kullanan ve kullanmayan kişiler için yapıldığında sigara kullanan kişilerin kullanmayanlara nazaran yaklaşık %50 daha fazla kanser riski taşıdıkları gözlenmiştir.In this study, indoor and outdoor environment samples were taken from different regions and microenvironments (home, school, office) in Kocaeli. Through active and passive sampling and measurement techniques, 16 heavy metals (Al, As, Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, S, Si, Ti, V and Zn) at 2 different particle fractions (PM2.5 and PM10), volatile organic compounds (VOCs), and SO2, NO2 and O3 concentrations were determined. Moreover, in an effort to establish the relationship between exposure and the indoor concentrations measured, personal samplers were used to determine personal exposure levels. Indoor/outdoor concentration ratios for NO2 were higher in homes than in schools or offices in both summer and winter, which shows that sources of NO2 pollutants in indoor environments of homes are more dominant than those found in offices or schools. The indoor/outdoor ratios were far below 1, indicating that O3 and SO2 are pollutants originating from outdoor environments and that they do not have significant sources in indoor environments. The presence of high levels of indoor and outdoor concentrations of crustal elements at PM2.5 fractions indicates that these elements are transported into indoor environments at high levels. PM2.5 personal exposure levels were 2–6 times higher than indoor levels for combustion-related elements such as As, S, V, Cu and Cr, and although there were some seasonal differences, the indoor/outdoor environment ratios generally ranged between 0.3–0.7 and indicated the effect of outdoor environments on the observed high personal exposure levels. The indoor/outdoor ratios for a major portion of the determined heavy metals at PM10 particle fractions were smaller than 1, showing that outdoor pollutants are more dominant than indoor pollutants. The highest VOC pollution levels were encountered in individuals in the sample, and this was followed by VOC pollution levels in indoor and outdoor environments. In both seasons, toluene levels were the highest pollutants for homes, offices and schools, followed by ethylbenzene, m/p-xylene, styrene, nonane, hexane, benzene, o-xylene and heptane. Total VOC concentrations obtained from urban areas were consistent with values obtained from industrial areas. Components that are indicators of traffic (BTEX, 1,2,4-trimethylbenzene) were measured at high levels in urban areas, while hexane and heptane components, which are indicators of petrochemistry, were recorded at high levels in high- industry areas. Moreover, VOC concentrations obtained from urban and industrial areas were higher than concentrations found in areas far from industry and traffic, which demonstrates the high contribution of traffic and industry to measured VOCs. This study investigated the summer and winter concentrations of selected pollutants and the relationship between indoor and outdoor environments. In order to determine pollutant sources that negatively contribute to air quality by affecting the degree of indoor, outdoor and personal exposures, the Positive Matrix Factorization (PMF) receptor modeling technique was used, which is a multivariate statistical analysis method. PMF, correlation analyses, indoor/outdoor ratios, microenvironment characteristics, responses to questionnaires, and time activity information suggested that industry, traffic and smoking represent the main emission sources of pollutants investigated. Indoor, outdoor and personal exposure concentration values were compared to values measured in different parts of the world, thereby evaluating consistency with the observed pollution level. Based on personal exposure concentrations, an assessment was conducted concerning the health risks associated with the inorganic and organic pollutants investigated in this study. When the calculated values for “Total Health Risk” and “Total Hazard Index” for people sampled in homes, offices and schools were examined by considering both the average concentrations and the worst scenarios, it was revealed that housewives are at the highest risk, followed by teachers and office workers. An examination of urban, industrial and far from urban, industrial and traffic areas revealed that people living in all of these three areas are subjected to high cancer risks, which are at similar levels. When the same evaluation was carried out for smokers and non-smokers, it was observed that smokers have a 50% higher risk of cancer compared to non-smokers
İzmir Aliağa endüstri bölgesinde hava kirliliğine neden olan organik ve inorganik kirleticilerin düzeylerinin, kaynaklarının ve sağlık etkilerinin belirlenmesi
TÜBİTAK ÇAYDAG01.07.200
Türkiye'nin değişik bölgelerindeki kırsal atmosfer aerosol komposizyonların karşılaştırılması
Long term data generated at four rural stations are compared to determine similarities and differences in aerosol compositions and factors contributing to observed differences at different regions in Turkey. The stations used in this study are located at Mediterranean coast (20 km to the west of Antalya city), Black Sea coast (20 km to the east of Amasra town), Central Anatolia (Çubuk, Ankara) and Northeastern part of the Anatolian Plateau (at Mt. Uludag). Data used in comparisons were generated in previous studies. However, some re-analysis of data were also performed; (1) to improve the similarities of the parameters compared and (2) to be able to apply recently-developed methodologies to data sets. Data from Mediterranean and Black Sea stations were identical in terms of parameters measured and were suitable for extensive comparison. However, fewer parameters were measured at Çubuk and Uludag stations, which limited the comparisons involving these two stations. Comparison included levels of major ions and elements, short-term and seasonal variations in concentrations, background (baseline) concentrations of elements, flow climatology of regions, correlations between elements, potential source areas affecting regions, and source types affecting chemical composition of particles. Comparison of levels of measured parameters in four regions showed that there are some differences in concentrations that arise from differences in the local characteristics of the sampling points. For example very high concentrations of elements such as Na and Cl in the Mediterranean region is attributed to closer proximity of the Antalya station to coast and not a general feature of the Mediterranean aerosol. There are also significant regional differences in the concentrations of measured elements and ions as well. Concentrations of anthropogenic elements are very similar at two coastalM.S. - Master of Scienc
İzmir - Aliağa bölgesindeki uçucu organik bileşiklerin ortam havasındaki seviyelerinin ve kaynaklarının belirlenmesi.
In this study, atmospheric levels and sources of VOCs at Aliağa industrial area was investigated. For this, VOC concentrations were measured at two monitoring stations through winter and summer campaigns in 2005 and 2006. Sampling stations were located in downtown Aliağa and downwind of industrial facilities, approximately 500 m to the south east of Horozgediği village. After the summer sampling, another temporary station was installed in between PETKİM and TÜPRAŞ, named as TÜPRAŞ Station to generate TÜPRAŞ and PETKİM profiles. More than 50 species were measured in all stations. In all stations, toluene has the highest contribution to total VOC concentration. Toluene is followed by m,p-xylene and benzene. While higher concentrations of traffic related VOCs were measured at Aliağa station, VOCs from industrial solvents and industrial processes were higher at Horozgediği station. The concentration levels in Aliağa and Horozgediği are found to be comparable to the other industrial regions reported in the literature. Investigation of episodes, diurnal variations of VOCs and meteorological parameters showed that PETKİM and TÜPRAŞ emissions affect the concentrations levels at Horozgediği and Aliağa stations. Source profiles of PETKİM and TÜPRAŞ are determined by using the TÜPRAŞ station data set. 2-methyl-hexane, benzene and 2,2,3-tri-methyl-butane+2,3-di-methyl-pentane are found to be good markers of PETKİM emissions. Ten different VOC sources were identified in the region. These were gasoline exhaust, diesel exhaust, natural gas use, gasoline evaporation, industrial emissions-1, natural gas construction, non-industrial solvent use, industrial emissions-2, PETKİM emissions, and mixed emissions from PETKİM and shipbreaking facilities.Ph.D. - Doctoral Progra
Atmospheric trace element and major ion concentrations over the eastern Mediterranean Sea: Identification of anthropogenic source regions
Concentrations of elements and ions measured in aerosol samples collected from March 1992 to the end of December 1993 were investigated to identify source regions affecting chemical composition of aerosols in the eastern Mediterranean atmosphere. Collected samples were analyzed for approximately 40 elements and ions using a combination of atomic absorption spectrometry, instrumental neutron activation analysis, ion chromatography and colorimetry. Statistical techniques, such as enrichment factors and a non-parametric bootstrapped potential source contribution function, were applied on the data set to determine main source types and source regions of anthropogenic particles in the eastern Mediterranean basin. Source regions of two previously defined anthropogenic components, namely a long-range transported component and a local pollution component, were identified. The main source areas for pollutants reaching the eastern Mediterranean basin were determined as southern and western parts of Turkey, central and eastern regions of Ukraine, east of Belarus, Greece, Georgia, Romania, coastal areas along France and Spain and coastal areas around the Black Sea, Russia. More distant source regions in the South of UK and Sweden, the central part of Algeria, the northeastern part of Turkey, Russia, Germany, Hungary, Czech Republic, Bosnia and Herzegovina, and coastal areas of Egypt, Israel and Italy do affect aerosol composition in the eastern Mediterranean, but transport from these regions cannot account for the highest 20% of the measured pollutant concentrations
Sources and source regions effecting the aerosol composition of the Eastern Mediterranean
Positive matrix factorization (PMF) was used to deduce the aerosol sources at a rural site on the Mediterranean coast of Turkey, using sample collected between February 1992 and December 1993. Approximately 600 daily aerosol samples were collected and 40 elements and compounds were analyzed by atomic absorption spectrometry, instrumental neutron activation analysis, ion chromatography and colorimetry
Seasonal and altitudinal changes in leaf nutrient concentrations of Hedera helix L. (Araliaceae)
Nutrient resorption is one of the most important nutrient use strategies developed by plants. The ratio of leaf area to dry mass (SLA) is related to leaf nutrients. In this study, the changes in SLA, N, P concentrations, N/ P ratio and C content of sun and shade leaves of the evergreen liana Hedera helix L. were investigated over the year in an altitudinal gradient. Foliar resorption efficiency (RE) and proficiency (RP) were also calculated in sun and shade leaves. Leaf traits significantly changed among studied localities and over the year. There were statistically significant differences between sun and shade leaves regarding SLA, N concentration and C content, but these were dependent on the differences of altitude. However, no significant differences were found for P concentrations between sun and shade leaves. SLA increased in sun and shade leaves at the end of the spring and decreased after the fall. Leaf C content generally increased in January. Leaf N concentration in sun and shade leaves was usually lowest in early summer and increased in October. The highest leaf P content was found between December and January in all localities. N/ P significantly differed between localities. Locality × time interaction was also significant except leaf P concentrations and N/ P. Positive correlations were seen between leaf and soil traits such as SLA, leaf N, P and C, soil moisture, N, P and C. PRE (Phosphorus resorption efficiency) and NRP (Nitrogen resorption proficiency) were significantly different among the localities, but not among sun and shade leaves. However, NRE (Nitrogen resorption efficiency) and PRP (Phosphorus resorption proficiency) were not significantly different. Sun and shade leaves of H. helix showed incomplete resorption, because, in all localities, NRP and PRP values were above the benchmark levels.Changements saisonniers et altitudinaux des concentrations foliaires en nutriments de Hedera helix L. (Araliaceae).
La résorption est l’une des plus importantes stratégies d’utilisation des nutriments développées par les plantes. Le ratio de la surface foliaire à la masse sèche (SLA) est lié aux nutriments foliaires. Dans la présente étude, les changements de concentration en SLA, N et P, le rapport N/ P et la teneur en C des feuilles de lumière et d’ombre de la liane sempervirente Hedera helix L. ont été étudiés au long de l’année sur un gradient altitudinal. L’efficience (RE) et l’efficacité (RP) de la résorption foliaire ont également été calculées dans les feuilles de lumière et celles d’ombre. Les traits foliaires ont montré des changements significatifs entre les localités et au cours de l’année. Des différences significatives sont apparues entre les feuilles de lumière et celles d’ombre pour ce qui concerne le SLA, la concentration en N et la teneur en C, mais se sont avérées dépendantes des différences d’altitude. Toutefois, aucune différence significative de concentration en P n’a été trouvée entre les feuilles de lumière et celles d’ombre. Dans les feuilles, tant de lumière que d’ombre, le SLA augmentait à la fin du printemps et baissait après l’automne. D’une manière générale, la teneur en C augmentait en janvier. La concentration en N des feuilles, tant de lumière que d’ombre, était habituellement la plus faible en début d’été et croissait en octobre. Les plus fortes teneurs en P ont été observées entre décembre et janvier dans toutes les localités. N/ P différait significativement selon les localités. L’interaction localité x temps était aussi significative sauf pour les concentrations en P foliaire et N/ P. Des corrélations positives ont été notées entre les traits foliaires et ceux du sol comme le SLA, les N, P et C foliaires, l’humidité du sol, et les teneurs en N, P et C. La PRE (efficience de la résorption du phosphore) et la NRP (efficacité de la résorption de l’azote) différaient de manère significative entre les localités mais pas entre les feuilles de lumière ou d’ombre. Cependant, la NRE (efficience de la résorption de l’azote) et la PRP (efficacité de la résorption du phosphore) n’étaient pas significativement différentes. Les feuilles de lumière et celles d’ombre ont montré une resorption incomplète car, dans toutes les localités, les valeurs de NRP et de PRP étaient supérieures aux niveaux de référence.Doğan Ahmet, Yalçin Erkan, Surmen Burak, Güray Kutbay Hamdi. Seasonal and altitudinal changes in leaf nutrient concentrations of Hedera helix L. (Araliaceae). In: Revue d'Écologie (La Terre et La Vie), tome 70, n°2, 2015. pp. 166-181
Seasonal and altitudinal changes in leaf nutrient concentrations of hedera helix L. (araliaceae)
WOS:000209954700005Nutrient resorption is one of the most important nutrient use strategies developed by plants. The ratio of leaf area to dry mass (SLA) is related to leaf nutrients. In this study, the changes in SLA, N, P concentrations, N/P ratio and C content of sun and shade leaves of the evergreen liana Hedera helix L. were investigated over the year in an altitudinal gradient. Foliar resorption efficiency (RE) and proficiency (RP) were also calculated in sun and shade leaves. Leaf traits significantly changed among studied localities and over the year. There were statistically significant differences between sun and shade leaves regarding SLA, N concentration and C content, but these were dependent on the differences of altitude. However, no significant differences were found for P concentrations between sun and shade leaves. SLA increased in sun and shade leaves at the end of the spnng and decreased after the fall. Leaf C content generally increased in January. Leaf N concentration in sun and shade leaves was usually lowest in early summer and increased in October. The highest leaf P content was found between December and January in all localities. N/P significantly differed between localities. Locality x time interaction was also significant except leaf P concentrations and N/P. Positive correlations were seen between leaf and soil traits such as SLA, leaf N, P and C, soil moisture, N, P and C. PRE (Phosphorus resorption efficiency) and NRP (Nitrogen resorption proficiency) were significantly different among the localities, but not among sun and shade leaves. However, NRE (Nitrogen resorption efficiency) and PRP (Phosphorus resorption proficiency) were not significantly different. Sun and shade leaves of H. helix showed incomplete resorption, because, in all localities, NRP and PRP values were above the benchmark levels.Research Council of Ondokuz Maps University [PYO.FEN.1901.10.029]This study was funded by the Research Council of Ondokuz Maps University (Project number: PYO.FEN.1901.10.029). Special thanks are due to Yuksel Terzi (PhD) for his valuable statistical help, to Siddik Yuksel (English lecturer) for his kind grammatical help and to the two anonymous referees who contributed to improve previous versions of this text