نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشگاه لرستان
2 عضو هیت علمی دانشکده کشاورزی دانشگاه لرستان
3 مؤسسة تحقیقات جنگل‌ها و مراتع کشور
4 استادیار گروه جنگلداری دانشکده کشاورزی دانشگاه لرستان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Measurement of tree biomass is considered as an important indicator for valuation of ecological and economical processes. One of traditional models for estimating trees biomass is allometric models.The purpose of the present study is determining allometric models for assessing biomass of planted Poplar clones in Flahhat garden in Khorramabad,Lorestan.
Materials and methods: First,the quantitative features of trees such as height,DBH and crown diameter were measured.Then,the sampling was done via randomized blocks method and a total of 50 trees were felled.A disc from the trunk and the crown of each tree was cut off at a thickness of 5-7cm and simultaneously weighed in the site.The samples were transferred to the laboratory and placed in an oven at 105 ° C for 24 hours.Using the dry weight / fresh weight ratio, the dry weight of the crown, trunk, and ultimately above-ground woody biomass was calculated.
Results:The results of regression models showed that the independent variable of DBH produced better models for dry matter biomass of tree and crown, while in the dry matter biomass of the trunk, the tree height was better. For data validation of each model, the mean square error was obtained. The lowest value for this model was for a second-degree model in terms of the independent variable of diameter at breast height (RMSE%=9/43، R2=0/79).
Conclusion: The results showed due to the high amount of coefficient of determination in the second-order model compared to other models, this model provided an opportunity to determine more suitable allometric relationships for these colonies.
Results:The results of regression models showed that the independent variable of DBH produced better models for dry matter biomass of tree and crown, while in the dry matter biomass of the trunk, the tree height was better. For data validation of each model, the mean square error was obtained. The lowest value for this model was for a second-degree model in terms of the independent variable of diameter at breast height (RMSE%=9/43، R2=0/79).
Conclusion: The results showed due to the high amount of coefficient of determination in the second-order model compared to other models, this model provided an opportunity to determine more suitable allometric relationships for these colonies.The results showed due to the high amount of coefficient of determination in the second-order model compared to other models, this model provided an opportunity to determine more suitable allometric relationships for these coloniesConclusion: The results showed due to the high amount of coefficient of determination in the second-order model compared to other models, this model provided an opportunity to determine more suitable allometric relationships for these colonies.The results showed due to the high amount of coefficient of determination in the second-order model compared to other models, this model provided an opportunity to determine more suitable allometric relationships for these colonies
کلیدواژه‌ها [English]
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