Department of Forest Products and Industries

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    Variations Among Forests, Plots and Trees of Acacia tortilis (Forssk.) subsp. raddiana (Savi) in Above-ground Wood Biomass and Carbon Content of Tree Components and their Inter-relationships in Semi-Arid Zone of Central Sudan
    (University of Khartoum, 2021) Hisham Saeed Abdeen Elzein
    ABSTRACT The study investigated a variation among A. tortilis subsp. radiana forests, plots within forests and trees within plots in four forests in semi-arid zone in Central Sudan. The study aimed to estimate aboveground volume (AGV), dry weight (DW), above ground biomass (AGB) and carbon content (CC) of tree, stems, and branches and their interrelationships. Data was collected from 36 variable-area sample plots randomly taken within the stocked area in each sample forest. For each tree in the plots, an average standing sample stem was divided into about 1-meter segments and their volumes were measured and the stump volume was added to obtain the volume of the sample stem and then multiplied by the number of stems per tree. Three branches of that stem were randomly selected and their volumes were calculated and the volume of branches per tree was then calculated. Above-ground wood volume of each tree was obtained by adding volumes of all stems and branches. Sample discs of 5 cm-thickness were cut from the felled sample stem, at the top of the stump and stem segments and the mid of branches (a total of 720 discs from all forests). From each disc, a wedge-shaped, 5 cm-thick piece of wood was used to determine the wood basic density and carbon ratio, and then dry AGB and CC were then estimated. The data were statistically analyzed using the Statistical Analysis System (SAS 1991) package. Tree (stems and branches) means and other basic statistics of the variables were computed (Proc Means) to describe the data obtained from sample trees and make statistical inference about the respective values of the population. Hence, 95% confidence intervals of the means were obtained for the population in the study area. The data was treated as a nested experiment and analysis of variance and variance components were conducted. Pearson correlation coefficient was obtained to investigate the linear association between all possible pairs of the studied variables. Plotting of the paired observations of all possible pairs of variables showed that the pattern of the relationships was linear. Simple linear regression analysis was performed for the paired variables that had strong correlations. Results of ANOVA showed that the sources of variation in all tree's variables were significant (p≤0.0001). It is concluded that the tree volume mean in the population is between 0.041 and 0.042 m3. Forests revealed the greatest proportion of variation in volume (22%) and dry weight (17.9%), while plots explained the largest one in carbon content (17.5%). The estimates of AGWB per hectare of the forests was found to vary between 13.68 and 20.47 t ha-1, and that of CC between 5.883329 and 10.27402 t C ha-1. The results of the correlation of all possible pairs of the studied variables were highly significant (p ≤ 0.0001) and positive. The obtained regression equations showed that the variation in stem volume was associated with large proportions of the variations in tree volume (R2= 0.89), tree dry weight (R2=0.83) and tree carbon content (R2=0.92). The stem volume was the best predictor of the studied tree variables. In future research, it is recommended to study biomass, carbon content of roots and soil carbon and to determine root/shoot ratio, biomass expansion factor (BEF), and biomass and CC of leaves.   المستخلص هدفت الدراسة لتوضيح التباين بين الغابات والمرابيع داخل الغابات والأشجار داخل المرابيع من اشجار السمر في الحجم والوزن الجاف ونسبة ومحتوى الكربون في الأشجار والسيقان والفروع وعلاقاتها المتبادلة في أربع غابات (عد ام دوم والمخولاب في شرق نهر النيل ووادي التمد وحفير دوكة في غرب النيل) في الاقليم شبه الجاف في وسط السودان. أيضا، تهدف الدراسة إلى تقدير الكتلة الحية والكربون فوق الأرض للأشجار والسيقان والأفرع في الهكتار وعلاقتها المتبادلة. جمعت البيانات من 36 مربوع من كل غابة تم اختيارها عشوائيًا داخل المنطقة المأهولة بالاشجار واختير ساق عشوائيا من كل شجرة في كل مربوع عينة وتم تقسيمه واقفا إلى قطع طولها حوالي متر وتم قياس أحجامها وأضيفت أحجامها للحصول على حجم الساق وضربه في عدد السيقان في الشجرة للحصول علي حجم السيقان في الشجرة. تم اختيار ثلاثة فروع من تلك الساق بشكل عشوائي وحُسبت أحجامها والحصول على متوسط للفروع الثلاثة وضرب المتوسط في عدد الفروع في الشجرة. ثم تم الحصول على حجم الكتلة الحية لكل الشجرة فوق الارض من خلال إضافة حجم جميع السيقان والفروع. في كل مربوع عينة من الستة وثلاثون في كل غابة، تم اختيار شجرة بشكل عشوائي من كل مربوع من تلك الأشجار (من تلك المقاسة أعلاه)، وتم قطعها وتم اختيار ساق واثنين من فروعها بشكل عشوائي. حيث تم اخذ عينة في شكل قرص بسماكة 5 سم من جذع العينة المقطوعة، في الجزء العلوي من الجذع وقطع الساق المقاسة سابقاً وفي منتصف الفروع (ما مجموعه 720 قرصًا من جميع الغابات). من كل قرص، تمت اخذ قطعة من الخشب على شكل إسفين، بسمك 5 سم واستخدمت لتحديد كثافة الخشب الأساسية. تم قياس الحجم الأخضر باستخدام طريقة إزاحة المياه. تم اخذ عينات أخرى، مماثلة ومجاورة لعينات الكثافة، تم طحنها واخذ منها واحد غرام لتحديد نسبة الكربون. تم ضرب متوسط نسبة الكربون في وزن الكتلة الجافة لتقدير وزن محتوى الكربون (كجم). تم تحليل البيانات إحصائيا باستخدام إجراءات حزمة نظام التحليل الإحصائي (SAS 1991). تم حساب الشجرة (السيقان والفروع) والإحصاءات الأساسية الأخرى للمتغيرات (Proc Means) لوصف البيانات التي تم الحصول عليها من أشجار العينات لإجراء استدلال إحصائي حول القيم الخاصة بمجتمع الدراسة. وبالتالي، تم الحصول على درجة ثقة 95 ٪ من متوسطات مجتمع الدراسة تقع في منطقة الدراسة. عوملت الدراسة الحالية كتجربة متداخلة وتم إجراء تحليل التباين ومكونات التباين .(PROC Nested) تم الحصول على معامل ارتباط بيرسون لبحث العلاقة الخطية بين جميع الأزواج الممكنة للمتغيرات المدروسة (Proc CORR). أظهر تخطيط الملاحظات المزدوجة لجميع أزواج المتغيرات المحتملة أن نمط العلاقات كان خطيًا. تم إجراء تحليل الانحدار الخطي البسيط (Proc REG) للمتغيرات الزوجية التي كانت لها علاقة قوية. أظهرت نتائج تحليل البياناتأن جميع مصادر التباين في جميع متغيرات الشجرة كانت كبيرة (P <0.0001). تشير نتائج حدود الثقة البالغة 95٪ إلى أن متوسط حجم الشجرة في مجتمع الدراسة كان يتراوح بين 0.041 و 0.042 متر مكعب. أوضحت الغابات أكبر نسبة من التباين في الحجم (22٪) والوزن الجاف (17.9٪)، في حين أوضحت مربوع العينة أكبر نسبة في محتوى الكربون (17.5٪). كانت تقديرات الكتلة الحية فوق سطح الأرض لكل هكتار من الغابات ما بين 13.68 و20.47 طن، و يقدر محتوى الكربون بين 5.883329 و10.27402 طن و كانت نتائج العلاقة بين جميع الأزواج الممكنة لمتغيرات الدراسة معنوية (P ≤ 0.0001) وإيجابية. أظهرت معادلات الانحدار التي تم الحصول عليها أن التباين في حجم الساق كان مرتبطًا بنسب كبيرة مع التباين في حجم الشجرة (R2 = 0.89)، الوزن الجاف للشجرة (R2 = 0.83) ومحتوى الكربون للشجرة.( R2= 0.92) كان حجم الساق هو أفضل مقدر لمتغيرات الأشجار التي تمت دراستها. في الأبحاث المستقبلية، يوصى بدراسة الكتلة الحيوية ومحتوى الكربون في الجذور وكربون التربة وتحديد نسبة الكربون بين الجذر/ والساق وعامل تمدد الكتلة الحيوية والكتلة الحيوية والكربون للأوراق.
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    Effect of Oxidation on some Physicochemical Properties of Gums from Acacia senegal and Acacia seyal var. seyal
    (University of Khartoum, 2020) Eljaily Mohamed Ahmed Mohamed
    Abstract: About 50 million people worldwide have epilepsy, and nearly 90% of epilepsy occurs in the developing countries. The mainstay of treatment of epilepsy is lifelong administration of anticonvulsant medications that can have major effects on the quality of life. Currently, there are 20 medications, approved by the Food and Drug Administration, for treatment of epileptic seizures in the US, one of them is Valproic acid but strong concern is its potential to cause sudden and severe, possibly fatal, liver impairments. Gum Arabic has been shown by several workers to have ameliorating effects on drug-induced hepatotoxicity. This study was carried out as a preliminary trial to investigate which constituent of Gum Arabic contributes to its hepatoprotective effect. Accordingly, manual fractionation of crude Gum Arabic was done. A protein-rich fraction of Gum Arabic was used, on its own (0.5g/kg) and in combination with Valproate (2ml/kg) in drinking water, for 20 male rats in four equal groups, once a day for 45 days. Blood samples were collected before treatment and thereafter, at two weeks intervals at day 15, 30 and 45. Four groups of rats were used. Group A received rich protein fraction plus Valproate. Group B received the protein-rich fraction only, Group C received water and Group D received Valproate alone. Assessment of liver function was followed by measuring liver transaminases and alkaline phosphatase together with estimation of total Bilirubin in blood. The comparison between groups showed significant results in reducing the trasnsaminase enzymes reaching (P<0.0001) for ALT serum level, ALP also recorded significant changes between the groups that reached maximum at day 45 (P<0.0001) Estimation of total Bilirubin showed a great decrease in the group that received protein-rich fraction of Gum Arabic in combination with Valproate compared with group that received Valproate alone. It is concluded that the supplementation of protein-rich fraction of Gum Arabic reduces hepatotoxicity that occurs as a side effect of a prolonged use of Valproate. المستخلص : يعاني حوالى50 مليون شخص في العالم من مرض الصرع، 90% منهم فى الدول الناميه إن العلاج الأساسي لمرض الصرع هي أدوية مضادة لنوبات الصرع والتي تؤخذ مدى الحياة لذلك يكون لها تأثيرات رئيسية على نوعية الحياة ويوجد حاليا 20دواء تمت الموافقة عليها من قبل إدارة الغذاء والدواء في الولايات المتحدة لمعالجة نوبات الصرع .أحد هذه الأدوية هي حامض الفالبرويك ، ولكن يوجد كثير من القلق ازاء استعماله وذلك لمقدرته المفاجئة والحادة لإضطراب الكبد وربما القاتلة.توصل عدد العاملين في هذا المجال الى ان للصمغ العربي تأثير في تخفيف سمية الكبد الناتجة عن الفالبوريت. هذه الدراسة تجربه أوليه لتحديد الجزئية من الصمغ العربي التي تساهم في حماية الكبد ، وإعتماداً على هذا تمت تجزئة الصمغ العربى بطريقه يدوية وأستخدم الجزء الغني بالبروتين منه على 20 من الفئران المقسمه ار بعه مجموعات متساويه، بإضافته في ماء الشرب لمدة 45يوم كعلاج مزدوج مع الفالبوريت. تم جمع عينات الدم قبل العلاج وبعد ذلك بأسبوعين في اليوم 15و30و45، وذلك لتقييم وظائف الكبد من خلال قياس إنزيمات الترانسامينات والالكلاين فوسفاتيز بالإضافه لتقدير البليروبين الكلي .وقد تلقت المجموعه (أ) الجزء الغنى بالبروتين من الصمغ العربى بالإضافه للفالبرويت و تلقت المجموعة(ب) جزء البروتين فقط والمجموعة (ج) تلقت الماء فقط و المجموعة(د) تلقت الفالبريت فقط. وأظهرت المقارنة بين المجموعات نتائج مقنعه في انخفاض قيم إنزيمات الترانسامينيز ووصلت إلى نفس القيمه للفوسفتايز كما بلغ مستوى البليروبين إنخافضا ملحوظا فى المجموعه (أ) مقارنة بالمجموعه (د). الخلاصه أن الجزء الغنى بالبروتين من الصمغ العربي يخفض سمية الكبد الناتجة عن الإستعمال طويل المدى للفالبوريت.
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    Effect of Relative Humidity, Species and Extractives on the Equilibrium Moisture Content of some Hardwood Species Growing in Sudan
    (UOFK, 2015-06-24) Zeinab Ahmed Abd EL Hameed, Ahmed ; Abd EL Azim Yassin Abd EL Gadir ; Forest Products and Industries
    This study was conducted to investigate the variation between hardwood in their responses to relative humidity changes and hot water extraction. Six wood species (Acacia nilotica, Acacia senegal, Anogeissus leiocarpus, Boswellia papyrifera, Ailanthus excelsa and Calotropis procera) growing in Northern and Southern Kordofan States were selected. For each species, wood samples were collected from six trees, from which specimens (1.5x 3.5x 5 cm) were prepared. Equilibrium moisture content was determined for these specimens at different relative humidities (0-95%) using various saturated salt solutions. The specimens were placed in a closed deisccator, which contained a saturated salt solution and then kept inside the oven at the specified temperature (60 and 90 oC) until the equilibrium moisture content was obtained. The effect of extractives was studied by comparing the equilibrium moisture content of extracted (hot water extraction) and unextracted wood. Desorption and adsorption isotherms of the six wood species exhibited sigmoid curves. The statistical analysis indicated a direct relationship between equilibrium moisture content and relative humidity that can be well explained by linear equation and third-order polynomial equations. There were significant differences in the equilibrium moisture content between species. At low relative humidities differences appear to be minimal, but at higher humidities differences among species are significant. The effect of extraction was significant at a few relative humidity values in some species; unextracted wood had higher equilibrium moisture content than extracted wood.
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    Effect of Extraction and Chemical Additives on Compressive Strength and some Physical Properties of Wood Cement Mixtures
    (University of Khartoum, 2015-06-23) Nazik Mohamed El Hassan Abd El Karim ; Abd El Azim Yassin Abd El Gadir ; Forest Products and Industries
    This study was under taken to investigate the effect of extraction and chemical additives on compressive strength and some physical properties of wood-cement mixture. Three factorial experiments were conducted using completely randomized design. The woody materials were obtained from four species, namely, Acacia nilotica, Acacia senegal, Acacia .seyal and Eucalyptus microtheca. The first experiment was designed to determine the effect of twelve chemical treatments (2% based on cement-weight) on the compressive strength of pure Portland cement. In total, 36 specimens were prepared using mortar cubes (7.06 cm3). After 24 hours the molded samples were removed from the molds and then soaked in water and left to cure for 28 days. The specimens prepared were tested for compressive strength using a universal-testing machine. Some of the chemicals (CaCI2, FeCI3, MgCl2 and CaCO3) improved the strength of cement while others (MgSO4, CaSO4, MgCO3, Na2SO4, Fe2(SO4)3 and Na2CO3) reduced its strength compared to the untreated cement (control). NaCI was not significantly different from the control. The second experiment was conducted to study the effect of extraction and chemical additives on wood-cement compatibility. The wood was extracted for 14 days and 11 chemicals were added at 2% (based in cement weight) to the mixture of un extracted and extracted wood with cement at a ratio of 1:8. In total 288 specimens were prepared. Planner shavings, cement and water were mixed; mortar cubes were prepared and tested for compressive strength in a universal testing machine after soaking in water for 28 days. Each of the three main effects (species, extraction and chemical additives) had a significant influence on the compressive strength; however, none of these factors was acting independently. Differences among species were significant at all combinations of treatments and chemical additives. The performance of species varied with chemical additives and treatments, however, Eucalyptus microtheca was always ranking high regardless of the chemical additives treatment. Acacia nilotica (the most inhibitory species when unextracted) was among the best performing species when treated with cold water and treated by various additives. Extracted Acacia seyal was always ranking low, however, it revealed best performance when untreated with cold water and treated by various chemical additives. Significant improvements in cement setting were achieved by the removal of water soluble extractives and sugars from Acacia nilotica and Acacia senegal wood. Such improvement however did not take place in Eucalyptus microtheca and Acacia seyal. Compressive strength of the four species (unrestracted or extracted) was significantly affected by the type of chemical used. Most of the chemical additives improved the setting of cement and its mixture with unrestracted wood and extracted wood. CaC12, caused great improvement in the compressive strength of wood-cement mixture and it ranked high regardless of the species and water extraction treatment. The greatest improvement in the mixture of cement with extracted Acacia nilotica and unrestracted Acacia senegal wood was obtained by the addition of FeCl3 and Mg C12 respectively. Based on the results of the second experiment, the best combination of chemical additive and extraction treatment (extracted or unrestracted) was added for each of the four species. The selected chemical additives were applied at seven levels (0.5, 1.0, 1.5,2.0,2.5, 3.0 and 3.5) based on cement weight. Planner shavings and cement were mixed at a ratio of 2% mortar cubes were prepared; the specimens were tested for compressive strength, water absorption, dimensional stability and density. The results showed that, increasing the levels of chemical additives in the mixture of the four species with cement was associated with an increase in compressive strength. No significant differences in water absorption were found between the seven levels of chemical additives when using extracted Acacia nilotica, unextracted Acacia senegal and Eucalyptus microtheca. Increasing the level of chemical additive was associated with an increase in density of Acacia nilotica and Acacia senegal extracted wood. Dimension swelling for all four species was very low and was slightly affected by differences in the level of the chemical additive.
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    Assessment and Mapping of Desertification in Western Sudan Using Remote Sensing Techniques and GIS.
    (University of Khartoum, 2015-06-22) Mohamed Mirghani Ali ; Abd El Aziz Mohamed Saed Baypimi ; Forest Production
    This study is an attempt to assess and map desertification in the western Sudan (Kordfan and Darfur). The objective of the study is to develop a methodology using remote sensing and geographic information system in assessment and mapping of desertification The western Sudan is of considerable importance to the Sudan's economy. It is ecologically vulnerable and has been exposed to recent desertification with very serious biological, social and financial losses. For these and other reasons the western Sudan has been chosen as a study area. Field data were gathered from sites of the research by the aid of GPS and interpreted satellite images. The remotely sensed data used in this study are NDVI images created from AVHRR sensor on board NOAA Satellites. The results produced from these NDVI images gave good indicators of vegetation degradation through the period 1982 - 1994 in the form of image maps. The final result is an image map of assessment of desertification which gives good indication of areas under risk of desertification. The areas desertified are divided into four classes including Light, Moderate, Severe and very Severe. The area for each class is assessed for each state and for the study area. The total area influenced by desertification, about 200000 Km2, is divided into four grades as follows: light = 101836 Km2, moderate = 68367 Km2, severe = 20817 Km2 and very severe = 8163 Km2. In 1982 (reference year) the boundary of desert shifted about 200 km south of the desert boundary estimated by Harrison and Jackson, 1958 .The study also shows that the desert area in western Sudan has increased from 205000 km2 ,estimated by Harrison and Jackson, 1958 to 340000 km2 , in 1982 and that the shifting southwards took place at the rate of 8 km per annum . To sum up it can be stated that remote sensing and geographic information system techniques for assessment and mapping of desertification over large areas of dry lands like western Sudan have been used with acceptable results. In conclusion the study strongly recommends the use of these new techniques in assessment and mapping of desertification in the Sudan so that its control can be achieved effectively.