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Modelling the Form Factor of Pinus brutia Ten. Trees Grown in Rabiaa Forests - Northern Lattakia

نمذجة معامل الشكل لأشجار الصنوبر البروتي Pinus brutia Ten. في غابات ربيعة في شمال اللاذقية

1938   1   131   0 ( 0 )
 Publication date 2014
and research's language is العربية
 Created by Shamra Editor




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Estimation of tree and stand volume is a key calculation for productive forest management (de Miguel et al., 2012). A precise estimation of tree volume needs to take the variation in bole forms into account while calculation, this can be done by estimating tree form factor. This study aims to construct a mathematical model to calculate the form factor of brutia pine trees grown in the regions of Rabiaa in northern Latakia. The form factor model can help foresters to precisely estimate the volume of tree and forest stands. During the period 2008-2011, 72 pine trees of various ages and sizes, located in natural stands of different densities and site qualities, were felled. Diameters at different heights of the felled trees were measured; trees volumes and volumes of equivalent cylinders were calculated, and consequently the values of tree form factor were computed. The dataset was randomly split into two parts, 75% (55 trees) of the data for constructing form factor model and 25% (17 trees) for model validation. A form factor model was obtained using the non-linear regression equations in the statistical program SPSS. Value of the coefficient of determination adjusted (R²adj) was about 0.81. The model has been validated using several statistical methods, the relative bias ( e%) was ca. 17.9%, while the value of model accuracy ) % x m ) was 22.9 %. In order to obtain lower value of model relative bias and higher value of accuracy it’s recommended to use a larger database comprising all distribution areas of pine in Syria.


Artificial intelligence review:
Research summary
تعتبر غابات الصنوبر البروتي في سوريا من النظم البيئية الهامة، وتلعب دوراً مهماً في الاقتصاد والبيئة. تهدف هذه الدراسة إلى تصميم نموذج رياضي لحساب معامل الشكل لأشجار الصنوبر البروتي في منطقة ربيعة شمال اللاذقية، مما يساعد في تقدير حجم الأشجار والمجموعات الحرجية بدقة أكبر. تم قطع 72 شجرة متنوعة في أعمارها وأحجامها خلال الفترة 2008-2011، وتم قياس أقطارها على ارتفاعات مختلفة وحساب حجومها وحجوم الأسطوانات المكافئة لها. استخدمت 75% من البيانات لتصميم النموذج و25% لاختبار جودته. تم الحصول على النموذج باستخدام معادلات الانحدار غير الخطي في برنامج SPSS، وبلغت قيمة معامل التحديد المعدل 0.81. أظهرت النتائج أن النموذج يمكنه تقدير معامل الشكل بدقة نسبية، ولكن ينصح باستخدام قاعدة بيانات أوسع لتحسين دقة النموذج.
Critical review
دراسة نقدية: تعتبر هذه الدراسة خطوة هامة نحو تحسين إدارة الغابات في سوريا من خلال تقديم نموذج رياضي لحساب معامل الشكل لأشجار الصنوبر البروتي. ومع ذلك، يمكن تحسين دقة النموذج من خلال توسيع قاعدة البيانات لتشمل مناطق انتشار أوسع للصنوبر البروتي في سوريا. كما أن استخدام تقنيات تحليل بيانات أكثر تطوراً قد يساهم في تحسين دقة النتائج. من الجدير بالذكر أن الدراسة اعتمدت على بيانات من منطقة محددة، مما قد يؤثر على تعميم النتائج على مناطق أخرى. لذا، يُفضل إجراء دراسات مشابهة في مناطق أخرى للتحقق من فعالية النموذج في ظروف بيئية مختلفة.
Questions related to the research
  1. ما هو الهدف الرئيسي من الدراسة؟

    الهدف الرئيسي هو تصميم نموذج رياضي لحساب معامل الشكل لأشجار الصنوبر البروتي في منطقة ربيعة شمال اللاذقية لتحسين دقة تقدير حجم الأشجار والمجموعات الحرجية.

  2. ما هي الفترة الزمنية التي تم خلالها جمع البيانات؟

    تم جمع البيانات خلال الفترة من 2008 إلى 2011.

  3. ما هي نسبة البيانات المستخدمة لتصميم النموذج واختباره؟

    تم استخدام 75% من البيانات لتصميم النموذج و25% لاختبار جودته.

  4. ما هو معامل التحديد المعدل للنموذج؟

    بلغت قيمة معامل التحديد المعدل للنموذج 0.81.


References used
BOYDAK, M. Silvicultural characteristics and natural regeneration of Pinus brutia Ten. – a review. Plant Ecology, No. 171, 2004, 153–163
DE-MIGUEL, S. MEHTÄTALO, L. SHATER, Z. KRAID, B. & PUKKALA, T. Evaluating marginal and conditional predictions of taper models in the absence of calibration data. Canadian Journal of Forest Research, No. 42, 2012, 1383–1394
MUHAIRWE, C.K. Tree form and taper variation over time for interior lodgepole pine. Canadian Journal of Forest Research, No. 24, 1994, 1904–1913
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This study was conducted in many natural sites in Al-Bayer and Al-Bassitregions inLattakiawhere there isthe main natural distribution of Brutia pine in Syria. The aim of the study is to analyse the relationship between the maincharacteristics of fo rest stands (forest mensuration) associated with silviculturetreatments, and plant diversity in the herbaceous layer of the forest. 32 circular plotsof 400 m2were sampled. Forest characteristics, plant species number and abundance(using Braun-Planquetindices)were recordedin each plot. Many diversity indices (SpeciesRichness, Shannon, Jaccard) were calculated. Species richness in the herbaceous layer correlated positively with age and negatively with volume, basal area, and forest cover in the over story. The effect of forest characteristics was more important on the vegetation composition than on the species richnessor Shannon index averages in the samples. Age was the most important characteristic influencing the vegetation composition, hence, the similarity between different age stages (expressed in Jaccard index). It is suggested in this study that when studying forest silviculture and management plans and when conserving biodiversity, life formsand functions must be considered instead ofthe traditional index.
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