1- Ilam University
Abstract: (462 Views)
Abstract
Introduction: The estimation of biomass of different tree organs plays a key role in sustainable management and estimation of forest carbon stocks. Relationships that relate the characteristics of tree size (such as diameter and height) to its biomass are called allometric relationships. This study aimed to determine the allometric equations for estimating biomass, carbon sequestration, and leaf area index of Acer monspessulanum subsp. Cinerascens species in the protected areas of Manshet and Ghalarnang forests in Ilam province.
Materials and Methods: For this purpose, initially, the different sites of Acer monspessulanum in the study area were determined by forest tour. After that, a total of 60 Acer monspessulanum trees were randomly selected, and their quantitative factors (such as large and small crown diameter, tree height, crown length, and collar diameter) were measured. To estimate the leaf biomass, a quarter to an eighth of the leaves of the tree crown were collected by the direct method of picking, according to the size and smallness of the tree crowns of the Acer monspessulanum sample trees. After drying the leaves in the oven, the dry weight of the leaves was measured. The numbers obtained from a quarter or an eighth of the crown surface by multiplying by numbers 4 or 8 became the dry weight of the leaves of the entire tree crown. The percentage of organic carbon (0.47%) was obtained by burning a sufficient amount of dried leaves in an electric furnace. The leaf area index of Acer monspessulanum subsp trees was also calculated using the specific surface area of the leaves, through the weighing method. Also, to generalize the results obtained from the sample trees to the whole forest, the average tree method was used. The Kolmograf-Smirnov test was used for the normality of the data. Linear and non-linear (logarithmic and power) regressions were used to examine the allometric relationships between the dependent variables of biomass, carbon sequestration, and leaf area index with the measured independent quantitative variables of the tree (such as average crown diameter, tree height). Based on the criteria of the coefficient of determination and the adjusted coefficient of determination, the best model was selected among the three investigated models. The decision to confirm or reject the assumption that the independent variable has no effect on the dependent variable was made based on p-value.
Results: The results of the Kolmogorov-Smirnov test showed that the data have a normal distribution. According to the results, the average leaf biomass, average carbon storage in leaves, and average carbon dioxide absorption from the atmosphere by Acer monspessulanum subsp. Cinerascens trees in the protected areas of Manshet and Ghalarnang were estimated to be 200.30 kg/ha, 94.16 kg/ha, and 345.68 kg/ha, respectively. The results of estimating the leaf area index in the study area showed that the average leaf area index for Acer monspessulanum subsp. Cinerascens species was 1.52 per tree and 0.119 per ha, respectively. The results of the analysis of different models showed that the independent variable of the collar diameter was not effective on the dependent variable of the leaf area index in any of the investigated regression models and its p value was more than 0.05 for all three regression models which shows that collar diameter has no significant effect on leaf area index. Meanwhile, the independent variables of the average diameter of the crown in all three investigated models showed a significant effect on the dependent variable of the leaf surface index based on the p value values. And the power model showed the highest coefficients of determination (0.407) and adjusted coefficients of determination (0.397) for the independent variable of the average diameter of the crown. The results of investigating the effects of independent variables (collar diameter, average crown diameter and average crown area) on the dependent variable of leaf dry biomass of Acer monspessulanum subsp. cinerascens trees in linear, logarithmic and power regression models showed that based on the p-value of all three independent variables in all three investigated models, they have a significant effect on the dry biomass of leaves of Acer monspessulanum subsp cinerascens trees. However, among other models, the power model had the highest coefficient of determination and adjusted coefficient of determination with values of 0.433 and 0.423, respectively, for the independent variable of collar diameter. Therefore, the power model is chosen as the best model for the independent variables of collar diameter and the dependent variable of leaf dry biomass. In addition, the results of the analysis of different models showed that the independent variable of tree collar diameter was effective on the dependent variable of leaf carbon sequestration in all regression models and its p-value was less than 0.05 for all three regression models which shows that the tree collar diameter variable has a significant effect on the dependent variable of leaf carbon sequestration. Meanwhile, among the investigated models, the power model for the independent variable of tree collar diameter has the highest coefficient of determination and adjusted coefficient of determination with the values of 0.434 and 0.424, respectively. Therefore, this model was chosen as the best model for the independent variable of tree collar diameter and the dependent variable of leaf carbon sequestration. Therefore, the examination of allometric relationships using regression equations showed that the power model had the best determination coefficient and adjusted determination coefficient for predicting dependent variables based on independent mentioned variables.
Conclusion: The results of this study demonstrate the ability to measure biomass, carbon sequestration, and leaf area index of Acer monspessulanum subsp. Cinerascens trees using allometric equations.
Introduction: The estimation of biomass of different tree organs plays a key role in sustainable management and estimation of forest carbon stocks. Relationships that relate the characteristics of tree size (such as diameter and height) to its biomass are called allometric relationships. This study aimed to determine the allometric equations for estimating biomass, carbon sequestration, and leaf area index of Acer monspessulanum subsp. Cinerascens species in the protected areas of Manshet and Ghalarnang forests in Ilam province.
Materials and Methods: For this purpose, initially, the different sites of Acer monspessulanum in the study area were determined by forest tour. After that, a total of 60 Acer monspessulanum trees were randomly selected, and their quantitative factors (such as large and small crown diameter, tree height, crown length, and collar diameter) were measured. To estimate the leaf biomass, a quarter to an eighth of the leaves of the tree crown were collected by the direct method of picking, according to the size and smallness of the tree crowns of the Acer monspessulanum sample trees. After drying the leaves in the oven, the dry weight of the leaves was measured. The numbers obtained from a quarter or an eighth of the crown surface by multiplying by numbers 4 or 8 became the dry weight of the leaves of the entire tree crown. The percentage of organic carbon (0.47%) was obtained by burning a sufficient amount of dried leaves in an electric furnace. The leaf area index of Acer monspessulanum subsp trees was also calculated using the specific surface area of the leaves, through the weighing method. Also, to generalize the results obtained from the sample trees to the whole forest, the average tree method was used. The Kolmograf-Smirnov test was used for the normality of the data. Linear and non-linear (logarithmic and power) regressions were used to examine the allometric relationships between the dependent variables of biomass, carbon sequestration, and leaf area index with the measured independent quantitative variables of the tree (such as average crown diameter, tree height). Based on the criteria of the coefficient of determination and the adjusted coefficient of determination, the best model was selected among the three investigated models. The decision to confirm or reject the assumption that the independent variable has no effect on the dependent variable was made based on p-value.
Results: The results of the Kolmogorov-Smirnov test showed that the data have a normal distribution. According to the results, the average leaf biomass, average carbon storage in leaves, and average carbon dioxide absorption from the atmosphere by Acer monspessulanum subsp. Cinerascens trees in the protected areas of Manshet and Ghalarnang were estimated to be 200.30 kg/ha, 94.16 kg/ha, and 345.68 kg/ha, respectively. The results of estimating the leaf area index in the study area showed that the average leaf area index for Acer monspessulanum subsp. Cinerascens species was 1.52 per tree and 0.119 per ha, respectively. The results of the analysis of different models showed that the independent variable of the collar diameter was not effective on the dependent variable of the leaf area index in any of the investigated regression models and its p value was more than 0.05 for all three regression models which shows that collar diameter has no significant effect on leaf area index. Meanwhile, the independent variables of the average diameter of the crown in all three investigated models showed a significant effect on the dependent variable of the leaf surface index based on the p value values. And the power model showed the highest coefficients of determination (0.407) and adjusted coefficients of determination (0.397) for the independent variable of the average diameter of the crown. The results of investigating the effects of independent variables (collar diameter, average crown diameter and average crown area) on the dependent variable of leaf dry biomass of Acer monspessulanum subsp. cinerascens trees in linear, logarithmic and power regression models showed that based on the p-value of all three independent variables in all three investigated models, they have a significant effect on the dry biomass of leaves of Acer monspessulanum subsp cinerascens trees. However, among other models, the power model had the highest coefficient of determination and adjusted coefficient of determination with values of 0.433 and 0.423, respectively, for the independent variable of collar diameter. Therefore, the power model is chosen as the best model for the independent variables of collar diameter and the dependent variable of leaf dry biomass. In addition, the results of the analysis of different models showed that the independent variable of tree collar diameter was effective on the dependent variable of leaf carbon sequestration in all regression models and its p-value was less than 0.05 for all three regression models which shows that the tree collar diameter variable has a significant effect on the dependent variable of leaf carbon sequestration. Meanwhile, among the investigated models, the power model for the independent variable of tree collar diameter has the highest coefficient of determination and adjusted coefficient of determination with the values of 0.434 and 0.424, respectively. Therefore, this model was chosen as the best model for the independent variable of tree collar diameter and the dependent variable of leaf carbon sequestration. Therefore, the examination of allometric relationships using regression equations showed that the power model had the best determination coefficient and adjusted determination coefficient for predicting dependent variables based on independent mentioned variables.
Conclusion: The results of this study demonstrate the ability to measure biomass, carbon sequestration, and leaf area index of Acer monspessulanum subsp. Cinerascens trees using allometric equations.
: Carbon sequestration, Leaf area index, Acer monespolinum, Manesht, GhelarangKeywords
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