Vertical Crown Fuel Distributions in Natural Calabrian Pine (Pinus brutia Ten.) Stands

Calabrian pine (Pinus brutia Ten.) is the most widely distributed coniferous species in Turkey. Forests mostly composed of Calabrian pine constitute the most flammable forests in fire sensitive regions of the country. Especially, regenerated and immature stands of this species have the most fire-prone fuel type. This study evaluates the results of vertical crown fuel distribution and develops some crown fuel models to explain canopy fuel characteristics in natural Calabrian pine stands. A total of 35 trees were cut down and crown fuels were determined vertically. The highest crown fuel load was generally situated in the middle part of tree crown. The percentage of needles in each crown section increased gradually from the beginning of lower parts to the upper parts of tree crowns for three stand types. Total crown fuel loads were determined as 5.66 kg for regenerated stands, 11.57 kg for immature stands and 17.44 kg for middle age stands, respectively. Correlation and regression analyses were performed to determine the relationship between needles, branches, available fuels, total crown fuels and tree properties. The results of crown fuel distribution and the allometric equations developed in this study can be used to predict vertical fuel load at any height from ground to the top of Calabrian pine stands. The results of this study will contribute to the verification and evaluation of fuel load prediction models in use, and enhance the understanding of crown fire behavior mechanism in forest fires

The incidence and infection status of the white mistletoe in Kazdağı fir forests of the West Black Sea region: A case study in Kökez Forest State Enterprise

Mistletoes is an important biotic pest that needs to be studied in terms of its wide distribution in forest areas, its potential damage and predictability of adverse effects of climate change. In this study, the incidence and infection status of white mistletoe (Viscum album ssp. abietis (Wiesb.) Abromeit.) in fir trees were investigated. The study was conducted in pure Kazdağı fir (Abies nordmanniana subsp. equi-trojani (Asch. & Sint. ex Boiss.) Coode & Cullen) forests spread within the borders of Bolu Forest Regional Directorate, Aladağlar Forest District Directorate, Kökez Forest State Enterprise. In the study, firstly, the incidence of mistletoe in fir trees was determined in 159 circular experimental plots determined with systematically. The incidence and infection status of mistletoe in tree crown structure were also observed and evaluated for mistletoe detected trees. “The Six-Class Dwarf Mistletoe Rating System” was taken into account in determining the incidence and infection status of white mistletoe and the degree of mistletoe infection. According to the study results, it was determined that mistletoe was found at the highest rates in forest areas below 1100 m altitude on the basis of sampling plots and tree level. Also, it was found that the incidence of mistletoe increased with the aid of the increase by diameter classes. The average mistletoe incidence rate for total of 4696 measured fir trees was found to be 22.64%. Also, the average mistletoe infection rate was found to be 2,42 as moderate level for 1063 infected fir trees. Mistletoe infection in three different crown parts of the tree was the lowest for the lower crown part and the highest for the upper crown part. The incidence of mistletoe in tree crowns showed significant differences in terms of diameter classes (2 = 1171.631, df = 3, p = 0.000). It was determined that the degree of mistletoe infection increased with increasing diameter values, and it was highest for trees located at low elevations and southern aspects. The decrease in the presence of mistletoe on trees due to the increase with altitude (2 = 83.570, sd=2, p= 0.000) was similarly found to be a negative relationship between the mean mistletoe infection degree and altitude (r = -0.416; p<0.01). The mean mistletoe infection degree was found to be 0.58 for the sampling points

Curvature Inheritance Symmetry In Riemannian Spaces with Applications to String Cloud and String Fluids

We study, in this paper, curvature inheritance symmetry (CI), $\pounds_{\xi}R_{bcd}^{a}=2\alpha R_{bcd}^{a}$, where $\alpha$ is a scalar function, for string cloud and string fluid in the context of general relativity. Also, we have obtained some result when a proper CI (i.e., $\alpha \neq 0$) is also a conformal Killing vector.Comment: 14 pages, Latex, no figures, to appear in the International Journal of Modern Physics D (IJMPD), Vol.8, No.5(Oct.,1999

Estimating fuel biomass of some shrub species (maquis) in Turkey

Regression equations were developed to estimate shrub fuel biomass of a maquis formation in western Turkey. The relationships between some shrub characteristics and live, dead, available (for consumption), and total fuel biomass were determined by simple/multiple linear regression. Measured biomass values for live, available, and total fuels varied from 0.70 to 6.74 kg m-2, from 0.78 to 3.03 kg m-2, and from 1.06 to 7.72 kg m-2, respectively. The results obtained indicated that shrub fuel biomass could be satisfactorily predicted using the regression equations generated. The resulting equations were able to account for 60% to 89% of the observed variation (P < 0.05) in the fuel biomass categories studied. The results of this study should be invaluable in many forestry disciplines, including ecology, protection, and managemen

Orman yangınları ve kuşlar

Aim of study: To present and discuss the behavior of some bird species and their habitat use during and after forest fires, and propose some suggestions for decision makers for forestry activities and management planning where forest fire intensively occur in forested areas. Area of study: Several forest fires that took place in different regions in Turkey in the last 10 years have been discussed. Some experimental fires conducted over the years were also included in the study. Material and Methods: Concerning the active forest fires; fire type, fuel type, characteristics of fire behavior were noted; head fire, flank and back fire observations were made and, after fire field observations and investigations were recorded. During and after the fire, bird species were observed in the field, identified and its behavior were recorded using binoculars, cameras and a video camera. Main results: Behavior of birds during and after fires were reported and discussed. It was observed that birds exploited the area instantaneously due to the sudden increase of food supply during the fire, and continued to utilize the area as the habitats became more suitable especially after fires. Research highlights: Fire affects living and non-living components of forest ecosystems. Birds are an important living component of the ecosystems that are both directly affected by fires and indirectly affected by changes in their habitats. Developmental stage (juvenile or mature), feeding habits and habitat use of birds are critical characteristics that are referred to in relation to the identification of benefits and losses due to firesÇalışmanın amacı: Orman yangınları esnasında ve sonrasında bazı kuş türlerinin davranış biçimleri ve habitat kullanımlarının ortaya konulması ve tartışılması ile ülkemizde yangınların yoğun bir şekilde gerçekleştiği ormanlık alanlardaki ormancılık faaliyetlerinin gerçekleştirilmesinde ve planlamalara konu edilebilmesinde karar vericilere bazı önerilerde bulunmaktır. Çalışma alanı: Türkiye’nin farklı bölgelerinde son 10 yılda çıkmış bazı orman yangınları ele alınmış ve tartışılmıştır. Ülkemizde gerçekleştirilmiş deneme yangınları da ayrıca araştırmaya konu edilmiştir. Materyal ve Yöntem: Aktif orman yangınlarına yönelik; yangın türü, yanıcı madde tipi, yangın davranışı özellikleri ve baş yangını ile kenar ve arka yangınlarına ilişkin gözlem ve incelemeler not edilmiştir. Yangın esnasında ve sonrasında alanda gözlemlenen kuş türleri ve davranışları, dürbün, fotoğraf makinesi ve video kamera gibi cihazlarla kayıt altına alınmış ve tür tespitleri yapılmıştır. Sonuçlar: Çalışmada, kuşların yangınlara karşı göstermiş oldukları davranışlar ve habitat kullanımları yangın esnasında ve yangın sonrası için değerlendirilmiştir. Kuşların, yangın esnasında ortaya çıkan ani besin kaynağı artışından anlık istifade ettikleri, yangın sonrasında ise genellikle daha uygun hale gelen bu habitatları daha fazla kullanmak için alanda bulundukları tespit edilmiştir. Araştırma vurguları: Yangınlar, orman ekosistemlerinde canlı ve cansız çevre üzerinde birçok etkiye sebep olmaktadır. Kuşlar, yangınlardan doğrudan ya da habitatlarında meydana gelen değişimler sebebiyle dolaylı olarak etkilenen önemli canlı gruplarındandır. Kuşların yangınlardan göreceği fayda ve zararın belirlenmesinde, yavru veya ergin olma durumu, beslenme alışkanlıkları, habitat kullanımları, yangının zamanı, boyutu ve türü gibi unsurlar kritik rol oynamaktadır

Thermal analysis of oriental beech wood treated with some borates as fire retardants

Wood is widely used as a construction material for many applications. To have knowledge about the thermal degradation characteristic of wood could be crucial for indoor and outdoor applications. Chemical treatments could improve the resistance of wood against fire and heat. In this study, to investigate the thermal properties of Oriental beech (Fagus orientalis) wood treated with 0,25%; 1% and 4,70% aqueous solutions of boric acid, borax, disodium octaborate tetrahydrate and mixtures of and in different proportions, thermogravimetric analysis, differential-thermogravimetry, and differentialthermal analysis were performed. Our results showed that borate treatment decreased the Tmax (maximum degradation temperature) and increased residual char amount. Higher concentration levels of borates resulted in higher char content of Oriental beech wood specimens. Residual char content of borate treated wood samples at fixed concentration of 4,70% ranked as in the following order: disodium octaborate tetrahydrate &gt; boric acid + borax (7:3) &gt; boric acid + borax (1:1) &gt; boric acid &gt; borax &gt;Control. The highest residual char content was achieved for the sample impregnated with 4,70% disodium octaborate tetrahydrate among the all treated samples

AĞAÇ İŞLERİ SEKTÖRÜNDE KİTOSANIN ODUN KORUMA MADDESİ OLARAK KULLANILMASI

Kitosan, doğada selülozdan sonra en çok bulunan amino polisakkarit olan kitinin deasetilasyonu sonucu elde edilmektedir. Günümüzde kitosan su arıtımında, kozmetikte, medikal alan gibi sektörlerde önemli kullanım alanı bulmuştur. Kitosanın çeşitli alanlarda değerlendirilmesiyle hem ekonomik açıdan kazanç hem de çevre açısından oldukça büyük yarar sağlanmaktadır. Kitosan polikatyonik yapısı sayesinde antibakteriyel, antifungal etkilere sahip olmakla beraber gerek insan sağlığına gerekse de doğaya hiçbir zararı yoktur. Kitosanın bu özelliklerini insanla iç içe olan ahşap malzemelerin korunması yönünde araştırmalar yapılmaktadır. Literatürde kitosan hem molekül ağırlığına göre hem de metalli kitosan bileşikleri sentezlenerek odun üzerinde koruyucu etkisi araştırılmıştır. Sonuç olarak bugüne kadar yapılan çalışmalar incelenerek eksik ve geliştirilmesi gereken yönleri tespit edilip irdelenmiştir.

FARKLI TUTKALLARIN KAYIN ve SARIÇAM AĞAÇLARINDAKİ YAPIŞMA DİRENÇLERİNİN BELİRLENMESİ

Bu çalışmada, poliüretan esaslı Pu-Mon ve Pu-Ma, polivinilasetat esaslı PVAc-MA22, PVAc-MA35 ve PVAc-MA50 ile yapıştırılmış Doğu kayını (Fagus orientalis L.) ve sarıçam (Pinus Sylvestris L.) odunlarının yapışma direnci, TS EN 205 esaslarına göre belirlenmiştir. Deney sonuçlarına göre, en yüksek yapışma direnci Pu-Ma (16.01 N/mm2) ve PVAc-MA35 (15.12 N/mm2) ile yapıştırılmış kayın numunelerinde, en düşük yapışma direnci ise Pu-Mon (7.98 N/mm2) ve PVAc-MA35 (7.67 N/mm2) ile yapıştırılmış sarıçam numunelerinde tespit edilmiştir. 

Investigation of the Effect of Cupric Chloride on Thermal Stabilization of Polyamide 6 as Carbon Fiber Precursor

An investigation on the role of cupric (Cu2+) ion incorporation during the thermal stabilization of polyamide 6 fibers was carried out using a combination of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) measurements. Cupric chloride pretreated and thermally stabilized polyamide 6 (PA6) fibers was characterized by a reduction in fiber diameter and linear density values together with color changes from light brown to black with increasing stabilization time. PA6 fibers were properly stabilized after 8 h of stabilization time prior to carbonization. The results obtained from DSC and TGA measurements indicated that there was an improvement in the thermal stability when cupric (Cu2+) ions were incorporated into the polymer structure. TGA thermograms showed the relative improvement in thermal stability as indicated by increasing char yield with progressing time. Char yield reached a maximum value of 33.6% at 1000 degrees C for the cupric chloride pretreated PA6 fibers stabilized for 12 h at 180 degrees C. Experimental results obtained from DSC and X-ray diffraction methods suggested the loss of crystallinity as a result of perturbation of hydrogen bonds with progressing time. The formation of cupric ion-amide coordination bonds improved the thermal stabilization by encouraging the development of ladder-like structures. The investigation resulted in a new method of evaluation of X-ray stabilization index specifically intended for the thermally stabilized PA6 fiber