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Variations in seasonal responses in water relations and total carbohydrate content (TCC) in one-yearold shoots from precommercially thinned (PCT) and unthinned Anatolian black pine stands were assessed during three seasons (sampling in May, July and September) in 2015-2017. Three different treatments were established: unthinned control with 4 941 stems.ha-1 and two thinned spacing levels (2-2.5 and 3-3.5 m) where 2 133 stems.ha(-1) and 1 093 stems.ha(-1) were left, respectively. Differences in osmotic potential at turgor loss point (Psi pi(TLP)) between the thinned and unthinned plots appeared only during a water shortage (September) in the second season, with the thinned stands showing lower Psi pi(TLP) than the unthinned stands. Seasonal variation in terms of Psi pi(TLP) was detected in the 3-3.5 m spacing trees. PCT were effective on osmotic potential at full turgor (Psi pi(100)), relative water content (RWC), symplastic water at saturated point per dry weight of the shoot and dry weight fraction. In both the thinned and unthinned plots, a gradual decline was observed in RWC from May to September in all three years. Generally, although TCC was found to be higher in the 3-3.5 m spacing, control plots were also high in carbohydrates in some periods. Results reflect the ability of this species to survive in changing environments by PCT during dry periods in the three studied seasons. Although PCT has an effect on water potential components and TCC, it is not clear exactly how effective the PCT density is in osmotic adjustment.

Bu çalışma Muğla - Gökova Orman Fidanlığında yetiştirilen yedi farklı populasyona (Mamadere, Karacahisar, Yapraktepe, Gökova, Çetibeli, Ağla ve Kıyra) ait 1+0 yaşlı çıplak köklü kızılçam (Pinus brutia Ten.) fidanların kalite düzeylerinin bazı morfolojik, fizyolojik ve biyokimyasal özelliklere göre değerlendirilmesi amacıyla gerçekleştirilmiştir. Kök boğazı çapı, boy, gövde kuru ağırlığı, kök kuru ağırlığı, tomurcuk sayısı, yan dal sayısı gibi morfolojik özellikler, fizyolojik özellikler olarak kök gelişme potansiyeli ve biyokimyasal özellikler olarak fotosentetik pigmentler ve toplan karbonhidrat içeriği belirlenmiştir. Araştırma sonucunda kök toplam karbonhidrat içeriği dışında ölçülen morfolojik, fizyolojik ve biyokimyasal özellikler bakımından populasyonlar arasında önemli farklılıklar belirlenmiştir. Mamadere populasyonu kalın çaplı, nispeten boylu, iğne yapraklarında toplam karbonhidrat içeriği yüksek fidanlara sahiptir. Tomurcuk sayısı, gövde/kök oranı, gürbüzlük belirteci ve Dickson kalite indeksi bakımdan Ağla populasyonu diğer populasyonlara göre daha kalitelidir. Karacahisar populasyonu fotosentetik pigmentler bakımından daha yüksek bulunmuştur. En ince çaplı ve TSE standartlarına göre dikime elverişsiz fidan yüzdesi yüksek populasyon Yapraktepe populasyonu olup, bu populasyona ait fidanlar çevresel etmenlere daha duyarlıdır.

The net photosynthetic rate (A), stomatal conductance (gs), and transpiration rate (E), chlorophyll content, and midday xylem water potential (Ψmd) of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe trees were studied in a natural stand (Burdur-Aziziye, Turkey) for the first (2015), second (2016) and third (2017) years after precommercial thinning (PCT) to better understand the physiological and biochemical responses of trees in a semiarid region. In this study, three treatments (control, 2–2.5 × 2–2.5 m and 3–3.5 × 3–3.5 m spacing) were applied. Soil water content (SWC) and soil temperature (ST) was greater in both PCT treatments than in the control treatments. In general, the control treatment had a lower Ψmd compared with PCT treatments. A, gs, and E are generally higher than PCT treatments applied with 3–3.5 m spacing. The lowest gs and E were determined in the control trees. Ψmd and A were positively correlated with SWC, but negatively correlated with ST. The decrease in stress level, improvement in resources, and reduced competition for resources by fewer trees increased the A and gs in trees in the PCT treatments. Chlorophyll a, chlorophyll b, and total chlorophyll content are higher in the control treatments as compared to PCT treatments. SWC, ST, Ψmd, A, gs, E, and photosynthetic pigment showed seasonal changes. The two PCT treatments were generally similar in the ecophysiological changes in plots and a longer time is needed to decide for PCT treatments applied with 3–3.5 m spacing. According to the results obtained, it is recommended that PCT be applied with spacings of 2–2.5 × 2–2.5 m.

Studies on the characterization and evaluation of plant genetic resources should be carried out in order to identify and conserve laurel (Laurus nobilis L.) gene resources from medicinal and aromatic plants of commercial importance in Turkey. This study was carried out with the aim of determining photosynthetic characteristics of containerized laurel seedlings grown from seeds collected from Antalya, Muğla and İzmir regions. Photosynthetic properties (net photosynthetic rate, transpiration, stomatal conductance, water use efficiency, chlorophyll a, chlorophyll b, total chlorophyll and carotenoid) were determined in the seedlings of three populations in August and October during the first growing season following sowing. According to the results obtained, in August, İzmir-Bayındır population had the highest net photosynthetic rate, stomatal conductance and transpiration rate, while Antalya-Manavgat population had the lowest values. In October, Muğla-Gökova population showed higher stomatal conductance, transpiration rate and carotenoid than others. The differences between the chlorophyll a, chlorophyll b and total chlorophyll contents of the populations were found to be statistically insignificant. Based on the photosynthetic pigment and gas exchange parameters, İzmir-Bayındır and Muğla- Gökova populations were found to be the most promising populations. These populations can be assessed in the future breeding program of laurel., Türkiye’de ticari öneme sahip tıbbi ve aromatik bitkilerden defne (Laurus nobilis L.) türünde gen kaynaklarının belirlenmesi ve korunması konusunda stratejilerin üretilebilmesi için genetik kaynakların karakterizasyonu ve değerlendirilmesine yönelik çalışmalar yapılmalıdır. Bu çalışma; Antalya, Muğla ve İzmir bölgesinden toplanan tohumlardan yetiştirilen tüplü defne fidanlarının fotosentetik özelliklerini karşılaştırmak amacıyla gerçekleştirilmiştir. Üç populasyona ait fidanlarda ekimi takiben birinci gelişme dönemi süresince ağustos ve ekim ayında fotosentetik (net fotosentez hızı, terleme, stoma iletkenliği, su kullanım etkinliği, klorofil a, klorofil b, toplam klorofil, karotenoid) özellikler incelenmiştir. Elde edilen sonuçlara göre Ağustos ayında en yüksek net fotosentez hızı, stoma iletkenliği ve terleme hızı İzmir-Bayındır populasyonunda belirlenirken, en düşük değerler Antalya-Manavgat populasyonunda tespit edilmiştir. Ekim ayında Muğla-Gökova populasyonuna ait fidanlarda terleme hızı, stoma iletkenliği ve karotenoid miktarı diğer populasyonlara göre daha yüksektir. Populasyonların klorofil a, klorofil b ve toplam klorofil içerikleri arasındaki farklılıklar istatistiksel olarak anlamsız bulunmuştur. Fotosentetik pigment ve gaz değişim parametrelerine bağlı olarak öne çıkan iki populasyon İzmir-Bayındır ve Muğla-Gökova populasyonu olmuştur. Bu populasyonlar defnenin gelecekteki ıslah çalışmalarında değerlendirilebilir.

Background: Understanding species’ reactions to environmental stressors (cold and drought) and characterizing drought tolerance can help us understand their ecosystem responses related to global change. This study aimed to understand and compare the drought and cold tolerance strategies of Juniperus excelsa, Juniperus foetidissima, and Juniperus oxycedrus, which are found in the Western Mediterranean Region. Water relation parameters [ΨTLP (osmotic potential at turgor loss point), Ψ100 (osmotic potential at full turgor), Ɛmax (bulk modulus of elasticity), V0/DW (symplastic water at the saturated point per dry weight of the shoot), RWC (relative water content)] in summer and winter were determined. Total soluble sugar and photosynthetic pigment content were identified in spring, summer, autumn, and winter. Results: J. foetidissima had lower Ψ TLP and higher Ɛmax in summer than other species. The species had similar Ψ TLP 1 Ψ 100 1 Ɛmax, V0/DW, and RWC in winter. A seasonal change was observed in total soluble sugar and photosynthetic pigment content. Total soluble sugar and photosynthetic pigment contents were related to mean air temperature and total precipitation. Conclusion: J. foetidissima was more tolerant to water deficit in the summer, whereas the three species reacted similarly to the cold in the winter.

We investigated the effects of precommercial thinning (PCT) applied at different levels on the growth parameters of natural Anatolian black pine stand. The experimental site was located in the province of Isparta in southern Turkey. PCT was set up using a randomized complete block design with three replicates and three treatments (control, 2–2.5 m × 2–2.5 m and 3–3.5 m × 3–3.5 m spacing). The experimental plots were established in March 2014. At the end of the growing seasons for three years (2014–2016), growth parameters such as diameter, height and crown radius were measured. PCT was found to be significantly effective on diameter, height, individual tree basal area, and crown radius increment at the end of the third year (p

Understanding how tree species respond to drought in their natural environment is needed to predict forest adaptation and management practices under global environmental changes. This study was carried out to determine and compare physiological and biochemical responses to variations in environmental conditions during summer drought of mixed natural stands of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe and Pinus brutia Ten. Midday xylem water potential (Ψmd), water relations, photosynthetic pigments, total soluble sugar and proline contents were investigated during the growing season. Ψmd followed a similar seasonal trend in both species but P. nigra subsp. pallasiana had higher Ψmd than P. brutia. The Ψmd gradually decreased from June, reached its lowest value in August, and then increased again. Gradual decreases in the osmotic potential at turgor loss point (ΨпTLP) were observed during the summer. Generally, ΨпTLP was lower in P. brutia. Total soluble sugars decreased from April to June for P. brutia, then increased and stayed relatively constant August to October. Similar changes were found at lower values in P. nigra subsp. pallasiana. Prolin accumulation and photosynthetic pigments were higher in P. brutia. The results indicate that physiological and biochemical responses of both species against changing environmental conditions were in different degrees but followed similar trends. P. nigra subsp. pallasiana is more sensitive to summer drought than P. brutia in their natural environment.

Bu çalışmada; Isparta il merkezinde bulunan ortalama 22 yaşındaki Toros sediri (Cedrus libani A. Rich) ve Anadolu karaçamı [Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe] ağaçlandırma sahasında yaz kuraklığı döneminde ağaçların su ilişkilerinde ve biyokimyasal özelliklerinde oluşan değişimler incelenmiştir. Haziran-eylül ayları arasında toprak nem içeriği ve sıcaklığı, su ilişkileri parametreleri [solma noktasındaki osmotik potansiyel (ΨπTLP), tam doygun haldeki osmotik potansiyel (Ψπ100), kuru ağırlık oranı (DWF), birim kuru ağırlık başına düşen simplastik su oranı (Vo/DW) ve relatif su içeriği (RWC)], toplam çözünebilir şeker ve prolin içeriği araştırılmıştır. Çalışmamızda toprak nem içeriği ve sıcaklığı dönemsel bir değişim göstermiştir. Ölçüm dönemlerinin toprak nem içeriği ve sıcaklığı üzerinde anlamlı etkisi vardır. Anadolu karaçamında ölçüm dönemlerinin ΨπTLP, Ψπ100 ve DWF üzerindeki etkisi istatistiksel anlamda önemsiz bulunmuştur. Toros sedirinde ölçüm dönemlerinin ΨπTLP, Ψπ100 ve RWC üzerinde önemli bir etkiye sahip olduğu belirlenmiştir. Solma noktasındaki osmotik potansiyel eylül ayında en düşük değerini almıştır. Toros sediri eylül ayında Anadolu karaçamına göre daha düşük solma noktasındaki osmotik potansiyele sahiptir. Anadolu karaçamında en yüksek toplam çözünebilir şeker içeriği haziran ayında tespit edilmiştir. Prolin içeriğinde ise, hem Anadolu karaçamında hem de Toros sedirinde ölçüm dönemlerinin etkisi bulunmamaktadır. Ağaç türleri arasında da toplam çözünebilir şeker ve prolin içeriği bakımından anlamlı bir farklılık tespit edilmemiştir. Toros sediri ve Anadolu karaçamı ağaçlandırma sahasında, çalışma yılında yapılan ölçüm sonuçlarına göre Eylül ayında Toros sedirinin Anadolu karaçamına göre kuraklığa karşı daha toleranslı olduğu söylenebilir., In this study, changes in water relations and biochemical characteristics of trees during summer drought in 22- year-old Taurus cedar (Cedrus libani A. Rich.) and Anatolian black pine [Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe] afforestation area located in central of Isparta were investigated. Soil water content and soil temperature, water relation parameters [osmotic potential at turgor loss point (ΨπTLP), osmotic potential at full turgor (Ψπ100), dry weight fraction (DWF), symplastic water at saturated point per dry weight of the shoot (Vo/DW) and relative water content (RWC)], total soluble sugar and proline content were determined between June and September. Soil water content and soil temperature showed a periodical change in our study. Measurement periods have a significant effect on soil water content and soil temperature. The effect of measurement periods on ΨπTLP, Ψπ100 and DWF was found to be insignificant in Anatolian black pine. Taurus cedar has a significant effect on the measurement periods as to ΨπTLP, Ψπ100 ve RWC. The osmotic potential at turgor loss point has the lowest value in September. Taurus cedar has lowest osmotic potential at turgor loss point than Anatolian black pine in September. The highest total soluble sugar content in Anatolian black pine was determined in June. There were no significant effects on measurement periods both Anatolian black pine and Taurus cedar in proline content. No significant differences were found between tree species as to total soluble sugar and proline content. According to measurement results in the studying year, in Taurus cedar and Anatolian black pine afforestation area, it can be said that Taurus cedar against drought is more tolerant than Anatolian black pine in September.

WOS: 000487577400004 Changes in gas exchange, photosynthetic pigments, midday xylem water potential (Psi(md)) and needle nutrient status of the trees and environmental conditions following precommercial thinning (PCT) in the naturally regenerated Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe stand was studied in forest districts of the western Mediterranean region of Turkey. An experiment involving two PCT treatments (spacing varied between 3.0 to 3.5 m and between 2.0 to 2.5 m) and one control (unthinned) was established in late April 2015. Different physiological responses to environmental changes following thinning were observed during the next three growing seasons. The soil water content (SWC) and temperature, Psi(md), chlorophyll pigments, needle N, P, and K concentrations, and gas exchange parameters were affected by PCT and the season. Compared to the unthinned plots, PCT increased the SWC and the soil temperature. The SWC was higher in the 3-3.5 m spaced plots. Increases in soil temperatures were generally similar between PCT treatments. The Psi(md), net photosynthetic rate (A), transpiration rate (E) and stomatal conductance (g(s)) of the trees in the thinned plots increased significantly compared to unthinned trees. This increase was attributed to increases in the SWC and decreases in soil temperature. The PCT with 3-3.5 m spacing had the highest Psi(md) and A or similar to the 2-2.5 m spacing. However, the A, E, and g(s) was higher at 2-2.5 m spacing in the dry period (July) of the second and third years after PCT. Needle N (May 2015), P (September 2015), and K (July 2016) concentrations increased after the PCT with 3-3.5 m spacing compared with the unthinned and the 2-2.5 m spacing. Needle K concentration was negatively correlated with Psi(md) and positively with WUE. A, g(s) and E were positively correlated with needle P concentration but not correlated with needle N concentration. The chlorophyll content of the unthinned trees remained high in the spring, similar to the 3-3.5 m spacing in the summer. The Psi(md), A, g(s) and E varied seasonally in both unthinned and thinned plots, with the higher values in the spring and lower values in summer. According to the short-term results, the PCT with the 2-2.5 m spacing appeared more appropriate when the 3-3.5 m spacing might negatively impact soil, water, and photosynthetic parameters in extreme drought years and management objectives such as improvement of stem quality are considered. TUBITAK (The Scientific and Technical Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TOVAG-114O659] This work was supported by the TUBITAK (The Scientific and Technical Research Council of Turkey, Project Number: TOVAG-114O659). We are also thankful for the support of the Isparta Forest Regional Directorate and its staff.

In forest nursery, the optimal lifting period can be change according to species, origin and growing techniques. Determining the optimal lifting period by the use of morphological characteristics may cause irreparable errors. Thus, it is also necessary to determine the physiological conditions of the seedling to accurately identify lifting period. In this study, effects of lifting date on physiological condition of the seedling were examined in order to determine the optimal lifting period in 2+0 aged Taurus cedar (Cedrus libani A. Rich) seedlings grown from two different provenances. Seedlings from Kapıdağ and Bucak provenances were lifted at 7 different dates from January to May in 2016. In each measurement time, water relations parameters by the pressure – volume (P-V) curve technique were estimated, including osmotic potential at full turgor (ψπ100), osmotic potential at turgor loss point (ψπTLP), free water content at turgor loss point (FWCTLP), relative water content at turgor loss point (RWCTLP), relative water content (RWC), symplastic water at saturated point per dry weight of the shoot (V0/DW), apoplastic water fraction (Va/VT) and dry weight fraction (DWF). In addition, root growth potential and total carbohydrate content in root and needle samples were determined. According to the results of this study, ψπTLP, ψπ100, total carbohydrate content in needle and roots, and root growth potential showed a seasonal change. In both provenances, ψπTLP and ψπ100 increased from late January to late February, then decreased early March and increased again to May. No significant differences were determined between measurement dates in FWCTLP and RWC. Total carbohydrate content in root and needles decreased gradually from late January to early May in both provenances. The root growth potential reached the maximum value on late February to Kapıdağ provenance and on early March to Bucak provenance and then fall. Seedlings lifted from January to early March had greater stress resistance than seedlings lifted in the late March, April or May. In Eğirdir forest nursery, although the safe period for lifting season are late January to early March, if weather conditions are adverse for lifting or planting, lifting period might be delayed until late March., Orman fidanlıklarında fidan söküm zamanı tür, orijin ve yetiştirme tekniklerine bağlı olarak değişebilmektedir. Uygun söküm zamanını sadece morfolojik özellikleri dikkate alarak belirlemek telafisi imkânsız hatalara neden olabilir. Bu nedenle, söküm zamanını doğru belirlemek için fidanın fizyolojik durumunu da belirlemek şarttır. Bu çalışmada, iki farklı orijinden yetiştirilmiş 2+0 yaşlı Toros sediri (Cedrus libani A. Rich.) fidanlarında uygun söküm zamanını belirleyebilmek amacıyla fidanın fizyolojik durumu üzerinde söküm zamanının etkileri incelenmiştir. Kapıdağ ve Bucak orijinli fidanların sökümü 2016 yılı ocak ayından mayıs ayına kadar belirli aralıklarla 7 farklı zamanda gerçekleştirilmiştir. Her bir ölçüm döneminde, basınç-hacim eğrisi tekniği yardımıyla su potansiyeli bileşenlerinden solma noktasındaki osmotik potansiyel (ψπTLP), doygun haldeki osmotik potansiyel (ψπ100), solma noktasındaki serbest su içeriği (FWCTLP), solma noktasındaki nispi su içeriği (RWCTLP), relatif su içeriği (RWC), birim kuru ağırlık başına düşen simplastik su miktarı (V0/DW), apoplastik su oranı (Va/VT) ve kuru ağırlık oranı (DWF) belirlenmiştir. Ayrıca, kök gelişme potansiyeli ile iğne yaprak ve kök örneklerinde toplam karbonhidrat içeriği belirlenmiştir. Çalışma sonuçlarına göre ψπTLP, ψπ100, iğne yaprak ve kök örneklerinde toplam karbonhidrat içeriği ve kök gelişme potansiyelinde mevsimsel bir değişim görülmüştür. ψπTLP ve ψπ100 her iki orijinde eş zamanlı olarak ocak sonundan şubat sonuna kadar yükselmiş, sonrasında mart başında bir düşüş gösterdikten sonra mayıs ayına doğru tekrar yükselmiştir. FWCTLP ve RWC’de ölçüm dönemleri arasında önemli bir farklılık belirlenmemiştir. Kök ve iğne yapraklarda toplam karbonhidrat içeriği her iki orijinde ocak sonundan mayıs başına doğru yavaş yavaş azalmıştır. Kök gelişme potansiyeli Kapıdağ orijininde şubat sonu, Bucak orijininde mart başında maksimum değere ulaştıktan sonra düşüşe geçmiştir. Ocak, şubat ve mart başında sökülen fidanların stres dayanıklılığı, mart sonu, nisan veya mayıs ayında sökülen fidanlardan daha yüksektir. Eğirdir Orman Fidanlığı koşullarında güvenli söküm zamanı ocak- mart başı dönem olarak tespit edilmesine karşın, söküm veya dikim için hava koşulları uygun değil ise, söküm zamanı mart sonuna kadar ileriye çekilebilir.

In this study, the effects of thedifferent levels of precommercial thinning (PCT) on growth parameters wasinvestigated in natural Anatolian black pine [Pinus nigra Arn. subsp. pallasiana(Lamb.) Holmboe] stand. PCT was designed three different levels (control, 2-2.5m and 3-3.5 m spacing) with three replicates in a randomised block design. Thestudy area was located within the boundaries of Burdur Forest ManagementDirectorate. PCT treatment was applied in March 2015 and diameter, height andcrown radius were measured at the end of the each growing seasons for threeyears. At the end of three years, precommercial thinning was found to bestatistically significant on diameter, height, individual tree basal area, andcrown radius increment. According to this, while the highest diameter andindividual tree basal area were determined in the PCT treatment with 3-3.5 mspacing, the highest height increment was found in the control plot. Crown radiusincrement was higher in the PCT treatment compared to the control plot at theend of three years. When effects of PCT on growth parameters in the short termwas evaluated, it was determined that PCT treatments applied with 3-3.5 mspacing has a positive effect on the development of trees except the heightincrement. However, long-term results and new research were needed to makedecisions in terms of high quality and yield., Buçalışmada, doğal Anadolu karaçamı [Pinusnigra Arn. subsp. pallasiana(Lamb.) Holmboe] meşceresinde farklı derecelerde uygulanan sıklık bakımınınbüyüme özellikleri üzerindeki etkisi araştırılmıştır. Sıklık bakımı işlemlerikontrol, 2-2.5X2-2.5 m ve 3-3.5X3-3.5 m aralık-mesafe olmak üzere rastlantıblokları deneme desenine göre üç yinelemeli olarak üç farklı düzeydeuygulanmıştır. Burdur Orman İşletme Müdürlüğü sınırları içerisinde yer alanaraştırma alanına, 2015 yılı mart ayında sıklık bakımı işlemi uygulanarak üçyıl boyunca her gelişme dönemi sonunda büyüme özelliklerinden çap, boy ve tepeyarıçapı ölçülmüştür. Üç yılın sonunda sıklık bakımı işlemlerinin çap, boy, tekağaçta göğüs yüzeyi ve tepe yarıçapı artımı üzerinde istatistiksel anlamdaönemli etkisinin olduğu belirlenmiştir. Buna göre en yüksek çap ve tek ağaçtagöğüs yüzeyi artımı sıklık bakımı 3-3.5 m aralıklarla uygulanan alandabelirlenirken, en yüksek boy artımı kontrol alanında tespit edilmiştir. Tepeyarıçapı artımı ise, üçüncü yılın sonunda kontrole kıyasla sıklık bakımı uygulananalanlarda daha yüksek çıkmıştır. Sıklık bakımının kısa dönemde büyümeözellikleri üzerindeki etkisi değerlendirildiğinde, boy hariç 3-3.5 maralıklarla uygulanan sıklık bakımı müdahalesinin ağaçların gelişimi üzerindeolumlu etkisinin olduğu tespit edilmiştir. Fakat, yüksek kalite ve verimaçısından karar verebilmek için uzun vadeli sonuçlara ve yeni araştırmalaraihtiyaç bulunmaktadır.

Effects of drought stress on growth, predawn xylem water potential (ψ pd ), osmotic solutes (soluble sugar and proline), and stomatal conductance were assessed in two oak ( Quercus cerris L. and Quercus robur L.) seedlings. Seedlings of both species were subjected to three drought treatments with the following irrigation intervals: well-watered (control: irrigation every 2-3 days), moderate drought stress (irrigation every 15 days), and severe drought stress (irrigation every 30 days). Drought-stressed seedlings of Q. cerris and Q. robur had more negative predawn xylem water potential than their well-watered seedlings. In Q. cerris , root collar diameter and root dry weights were negatively influenced by drought, while height, shoot dry weight, and root:shoot ratios were unaffected. Height and shoot dry weight of drought-stressed Q. robur were decreased, while root:shoot ratio increased. Drought caused significant decreases in stomatal conductance of both species. Q. cerris seedlings sustained higher stomatal conductance compared with Q. robur . Proline and soluble sugar increased in response to drought stress. Q. robur had a higher proline accumulation than Q. cerris . These findings suggested that the Q. cerris and Q. robur seedlings showed a drought stress adaptive mechanism either by restricting their growth or increasing root:shoot ratio or by decreasing water loss (reduced stomatal conductance) and accumulating of osmotic solutes.

Variations in the photosynthetic pigments and total carbohydrate contents of needles of different age classes (current-year, 1-year-old, 2-year-old and 3-year-old) of Pinus nigra subsp. pallasiana (Lambert) Holmboe trees in a young natural stand were investigated during the growing season. In current-year needles, total carbohydrate content was lower during June and July when the needle growth continued than in older age classes, but it was similar to other age classes in the months of August to October. Seasonal patterns of variations in total carbohydrate content were almost similar in 1-, 2-, and 3-year-old needles. Chlorophyll and carotenoid contents increased from May to June, remained relatively constant or declined slightly during summer and autumn in 1-, 2-, and 3-year-old needles. In October, the pigment content was highest in 1-year-old needles, and lowest in 3-year-old needles. Our study indicated that total carbohydrate and pigment contents were affected by needle age classes and seasons. © 2018 Czech Academy of Agricultural Sciences. All rights reserved.

Bu çalışmada, Eğirdir Orman Fidanlığı’nda yetiştirilen Anadolu karaçamı fidanlarında uygulanan yerinde kök kesimlerinin morfolojik özellikler üzerindeki etkisi araştırılmıştır. Çalışmada bir yaşını doldurmuş fidanlarda 5 cm mesafe ile seyreltme yapıldıktan sonra kontrol dahil toplam 11 adet işlem (alttan kök kesimleri, yandan kök kesimleri ve kombinasyonu) uygulanmıştır. Sonuç olarak, yerinde kök kesimleri fidan morfolojik özellikleri üzerinde etkilidir. TS 2265/ Mart 1976 standardına göre en kaliteli fidanlar, sadece haziran ayında bir kez alttan kök kesimi ile birlikte yandan kök kesimi uygulanan işlemden elde edilmiştir. Fidanlığın rutin uygulamasından elde edilen fidanlar diğer işlemlere göre daha boylu olmalarına karşın birçok morfolojik özellik bakımından düşük değerlere sahiptir.

Bu çalışmada, ekim sıklığının 1+0 yaşlı Acer negundo L. fidanlarının bazı morfolojik ve fizyolojik özellikleri üzerindeki etkisi incelenmiştir. Fidanlar dört farklı ekim sıklığı işleminde (35, 30, 20 ve 10 g/m2) yetiştirilmiştir. Birinci gelişme dönemi sonunda fidanların morfolojik (fidan boyu, kök boğazı çapı, kuru ağırlıkları, gövde/kök oranı ve kök yüzdesi) ve fizyolojik özellikleri (kök gelişme potansiyeli ve toplam karbonhidrat içeriği) belirlenmiştir. Ekim sıklığı fidan morfolojik özellikleri ile fizyolojik özelliklerden sadece kök gelişme potansiyeli üzerinde etkilidir. 10 g/m2 ve 20 g/m2 ekim sıklığında yetişen fidanlar 30 g/m2 ve 35 g/m2 ekim sıklığında yetişen fidanlara göre daha kalın çaplı, daha boylu ve daha ağırdır. Ekim sıklığının artmasına bağlı olarak kök gelişme potansiyeli düşmüştür. Eğirdir Orman Fidanlığı koşullarında 10 g/m2 ekim sıklığının uygulanması kaliteli fidan üretimi için daha uygundur. Metrekarede daha fazla sayıda fidan istenmesi durumunda, 20 g/m2 ekim sıklığı da kullanılabilir

Determining the adaptability to abiotic conditions and potential establishment success of tree species needs to be conducted before attempting to use a species in large-scale afforestation programs. In this study, the chemical and physiological performance of four Turkish red pine (Pinus brutia Ten.) provenances was investigated after exposure to artificial cold temperature treatments to determine their adaptability to cold environment for potential use in afforestation programs. Seeds were sown and raised for 24, 28, and 32 weeks and exposed to decreasing temperatures in an artificial freezer. Relative electrolyte leakage, chlorophyll fluorescence, and carbohydrate concentrations were measured to determine the variability between provenances. Results showed that diameter and height growth did not vary with origin for each of the three growth stages measured. Root electrolyte leakage values differed between provenances, confirming that cold stress was effectively causing physiological damages when plants were exposed to temperature at −15 °C and below. The variability observed in the relationship between provenances and cold hardiness responses can be attributed to tree-to-tree variability within provenances and microsites conditions. There was generally no significant difference in chlorophyll fluorescence between provenances, also attributed to low genetic variation between provenances. Carbohydrate concentrations were also very variable and varied significantly among growth stages and provenances. High-altitude provenances had higher soluble carbohydrates concentrations in several cases, suggesting a relationship between altitude, soluble sugars, and cold hardiness. However, these trends were not consistent; therefore, we suggest that such hypotheses be confirmed through more comprehensive further studies.

In this study, the effects of seedbed density on one year-old hawthorn (Crataegus monogyna Jacq.) seedlings characteristics (root collar diameter, seedling height, shoot and root dry weights and root/shoot ratio) and root growth potential were investigated. Five different seedbed density (control, 3, 6, 9 and 12 cm) were applied in Egirdir Forest Nursery. As a result, different seedbed density were significantly affected root collar diameter, seedling height, shoot and root dry weights except root/shoot ratio and root growth potential. The highest root collar diameter, seedling height, shoot and root weights were obtained from seedling which is grown with 9 and 12 cm seedbed density while control seedlings had lowest in nursery. Under conditions of Egirdir Forest Nursery, seedlings should be thinned to 6 or 9 cm in distance to produce taller seedlings with larger diameter.Keywords: Hawthorn, Seedbed density, Morphology, Physiology, Bu çalışmada farklı yetiştirme sıklıklarının 1+0 yaşlı alıç (Crataegus monogyna Jacq.) fidanlarının morfolojik özellikleri (kök boğazı çapı, fidan boyu, kök ve gövde kuru ağırlıkları, gövde/kök oranı) ile kök gelişme potansiyeli üzerindeki etkileri araştırılmıştır. Eğirdir Orman Fidanlığı’nda fidanlar arasında 3, 6, 9 ve 12 cm mesafe olacak şekilde kontrol dahil beş farklı yetiştirme sıklığı işlemi uygulanmıştır. Alıç fidanlarında farklı derecelerde uygulanan yetiştirme sıklığı, gövde:kök oranı ve kök gelişme potansiyeli hariç kök boğazı çapı, fidan boyu, gövde ve kök kuru ağırlığı üzerinde etkili bulunmuştur. En yüksek kök boğazı çapı, fidan boyu ve kuru ağırlıklar fidanlıkta 9 ve 12 cm mesafe ile yetiştirilen fidanlarda belirlenirken, en düşük değerler kontrol fidanlarında tespit edilmiştir. Eğirdir orman fidanlığı koşullarında ekimlerin fidanlar arası mesafesi 6 veya 9 cm arasında olacak şekilde seyreltilmesi daha kalın çaplı ve boylu fidan üretilmesi açısından uygun olacaktır.Anahtar kelimeler: Alıç, Yetiştirme sıklığı, Morfoloji, Fizyoloji

Bu çalışmada, 1+0 yaşlı çıplak köklü kokulu ardıç (Juniperus foetidissima Wild.) fidanlarında yetiştirme sıklığının fidan morfolojisi, kök gelişme potansiyeli ve toplam karbonhidrat içeriği üzerindeki etkileri incelenmiştir. Ayrıca fidanların TS2265/Mart 1976 ve TS2265/Şubat 1988 tarihli fidan kalite standartlarına göre değerlendirmeleri yapılmıştır. Ekim yastığındaki 1 m2 lik alanlarda 7 ekim çizgisi üzerinde biri kontrol olmak üzere 6 farklı yetiştirme sıklığı işlemi [100, 150, 200, 300, 400, 700 (kontrol) fidan/m²] uygulanmıştır. Çalışma sonuçlarına göre, yetiştirme sıklığı kök boğazı çapı, fidan boyu, gövde, kök ve fidan kuru ağırlığı, gövde/kök oranı, kök yüzdesi, Gürbüzlük belirteci, Dickson kalite indeksi, toplam kök karbonhidrat içeriği ve kök geliştirme potansiyeli üzerinde etkili olmasına karşın, yan dal sayısı üzerinde etkili değildir. Metrekarede 100 adet fidanın bulunduğu işlemde yer alan bireyler daha büyük kök boğazı çapına, gövde kuru ağırlığına ve daha yüksek kök gelişme potansiyeline sahiptir. Çalışma sonuçlarına göre kokulu ardıç türünde hem daha iyi fidan gelişimini sağlamak hem de daha çok sayıda kaliteli fidan elde etmek için ekim çalışmalarında metrekarede 100 adet fidanın bulunmasının Eğirdir Orman Fidanlığı koşullarında uygun olacağı söylenebilir. Ayrıca, bu çalışmanın sonuçları fidanlıkta en fazla 400 fidan/m² sıklığının kullanılabileceğini de işaret etmektedir.

The effects of cold storage duration on the physiological characteristics and growth of two-year-old Taurus cedar (Cedrus libani A. Rich) seedlings were studied. Taurus cedar seedlings were lifted in December, January and February and stored at +4 °C (cold storage) for 0, 2, 3 and 4 months. Xylem water potential (Ψ), shoot (SMC) and root moisture (RMC) contents, root growth potential (RGP), root electrolyte leakage (REL) and total carbohydrate contents were determined before and after the cold storage. The survival and growth were also evaluated at the end of the first growing season. Ψ, SMC and RMC, RGP and total carbohydrate contents were dramatically affected by the storage duration. The decrease in total carbohydrate contents during the storage showed a parallelism with RGP and survival. It was also found that storage duration had important effects on survival and growth. While survival was above 85 % even after storage of 4 months in seedlings that were lifted in December and January, this rate was reduced to 30 % after storage of 4 months in seedlings that were lifted in February. Total carbohydrate content and RGP can be used as an indicator of survival after cold storage.

Bu calisma, Denizli Orman Fidanligi’nda yetistirilen 1+0 yasli kizilcam ( Pinus brutia Ten.) fidanlarin bazi morfolojik, fizyolojik ve biyokimyasal ozellikleri uzerinde tohum kaynaginin etkisini belirlemek amaciyla gerceklestirilmistir. Dort kizilcam tohum bahcesinden (Tavas-Kale, Cameli-Goldag, Mugla-Kiyra, Yilanli-Boyali) saglanan tohumlardan uretilen fidanlarin morfolojik (fidan boyu, kok bogazi capi, kuru agirliklari, govde/kok orani vb.), fizyolojik (Su potansiyeli bilesenleri, kok gelisme potansiyeli) ve biyokimyasal (toplam cozunebilir sekerler) ozellikleri birinci gelisme donemi sonunda belirlenmistir. Arastirma sonucunda morfolojik ozelliklerden fidan boyu, gurbuzluk belirteci ve Dickson kalite indisi icin tohum bahceleri arasinda anlamli farkliliklar belirlenmistir. En uzun boylu fidanlar Tavas-Kale orijinli tohum bahcesi fidanlarindan saglanirken, en kisa boylu fidanlar Yilanli-Boyali orijinli tohum bahcesi fidanlarindan saglanmistir. Kok gelisme potansiyeli ve ibre toplam cozunebilir seker icerigi uzerinde tohum bahcelerinin onemli etkileri bulunmaktadir. Tavas-Kale orijinli tohum bahcesine ait fidanlar en yuksek kok gelisme potansiyeli gostermistir. Mugla-Kiyra orijinli tohum bahcesinde daha kalin capli, daha agir ve daha kaliteli fidanlar elde edilmistir.

In this study, the effect of irrigation intervals (drought stress) on growth, predawn xylem water potential (Ψ w), the osmotic potential at full turgor (Ψπ 100), the osmotic potential at the turgor loss point (Ψπ TLP), osmotic adjustment and osmotic solutes (soluble sugars and proline) of Pinus pinea L. seedlings were examined. An experiment was carried out under greenhouse conditions using four watering treatments (control, 7-, 14- and 21-day irrigation intervals) in the first growth season; from mid-July to early November. Results showed that irrigation interval had significant effect on growth characteristics, Ψ w, water relation parameters, and osmotic solutes. The increasing irrigation interval significantly decreased the seedling height, root collar diameter, root, stem and needle dry weight, number of lateral branches, root percentage, root:shoot ratio and diameter:height ratio. Ψ w and total soluble sugars decreased while proline content increased with the increase of drought stress. The Ψπ 100 and Ψπ TLP significantly decreased in drought-stressed seedlings compared to control (no stress) seedlings. The results suggest that the impact of drought stress increased with the increase of irrigation interval. Therefore, in the drought-stressed P. pinea seedlings were indicated osmotic adjustment by increasing the proline content and decreasing Ψπ 100 and Ψπ TLP during drought stress. Growth decreased under drought stress conditions in P. pinea seedlings.

Bu calismada, 1+0 yasindaki ciplak koklu kokulu ardic ( Juniperus foetidissima Wild.) fidanlarinda su potansiyeli bilesenlerinde meydana gelen donemsel degisimler incelenmistir. Ekim 2011 tarihinden Nisan 2012 tarihine kadar dort haftalik araliklarla fidanliktan fidan sokumu gerceklestirilmistir. Her bir olcum doneminde basinc-hacim egrisi teknigi yardimiyla su potansiyeli bilesenleri olculmus ve solma noktasindaki osmotik potansiyeli (ψ πTLP ), doygun haldeki osmotik potansiyeli (ψ π100 ), solma noktasindaki serbest su icerigi (FWC TLP ), solma noktasindaki nispi su icerigi (RWC TLP ), birim kuru agirlik basina dusen simplastik su miktari (V 0 /DW), apoplastik su fraksiyonu (V a /V T ) ve kuru agirlik orani (DWF) belirlenmistir. Calisma sonuclarina gore sadece solma noktasindaki osmotik potansiyelinde mevsimsel bir degisim gorulmustur. Solma noktasindaki osmotik potansiyel ekim ayindan itibaren yavas yavas azalmis ve en dusuk degerlere aralik ayinda ulastiktan sonra tekrar artarak nisan ayinda yuksek degerler almistir. Diger su potansiyeli bilesenlerinde (ψ π100 , FWC TLP, RWC TLP , V 0 /DW, V a /V T and DWF) olcum donemleri arasinda onemli bir farklilik belirlenmemistir. Aralik, ocak ve subat doneminde sokulen fidanlarin stres dayanikliligi, ekim, kasim, mart veya nisan ayinda sokulen fidanlardan daha yuksektir. Egirdir Orman Fidanligi kosullarinda guvenli sokum donemi aralik sonu - subat sonu donem olarak tespit edilmesine karsin, sokum veya dikim icin hava kosullari uygun degil ise, sokum zamani kasim sonuna kadar one veya mart sonuna kadar ileriye cekilebilir.

Seasonal changes in water relations parameters, dry weight fraction (DWF), and root growth potential (RGP) were examined for Anatolian black pine [Pious nigra Arn. subsp. pallasiana (Lamb.) Holmboe] seedlings. In addition, phenological conditions were monitored. Water relations parameters were estimated using the pressure-volume technique, including osmotic potential at full turgor (psi(pi 100)) osmotic potential at turgor loss point (psi(pi TLP)), free water content at turgor loss point (FWCTLP), relative water content at turgor loss point (RWCTLP) and symplastic water/dry weight (Vo/DW). psi(pi TLP), psi(pi 100), DWF, and RGP showed seasonal changes, but FWCTLP, RWCTLP, and Vo/DW did not show a clear seasonal change. The osmotic potentials (psi(pi TLP) and psi(pi 100)) increased rapidly during rapid shoot elongation, then decreased gradually until autumn, and the minimum values were reached in midwinter. DWF and RGP were highest at the end of January and in mid-February, respectively. The results of the study were discussed based on nursery practices (e.g. lifting and planting time, quality of seedlings) for the species, and as a synthesis of these results, mid-November through mid-March was suggested as the lifting and planting period for bare root Anatolian black pine seedlings.