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## Comparison of allometric equations to estimate the above-ground biomass of Populusalba species (Case study; poplar plantations in Chaharmahal and Bakhtiari province, Iran) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

Caspian Journal of Environmental Sciences | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

مقاله 5، دوره 13، شماره 3، پاییز 2015، صفحه 237-246
اصل مقاله (715 K)
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نوع مقاله: Research Paper | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

چکیده | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

Carbon sequestration into plants biomass, especially in fast growing trees is an easier and economically way for dropping off CO2 from atmosphere. This study was carried out in order to investigate above-ground biomass of white poplar (populous alba, L.) plantations that was planted in fourdifferent plant spacing (0.5 × 0.5, 1×1, 2×2 and 4×4 m.) in Chaharmahal and Bakhtiari province in west of Iran. Selecting the trees was according to diameter classes. After inventory, 10 trees were selected from each density at one hectare area. The tree’s characteristics including diameter at breast height (DBH), total height, and crown diameter measured. Then measured trees felled down in order to measure the wet and dry weight of different organs including (whole tree, trunk, main branches, twigs and leaf).The regression analysis was applied to find out a relationship between mass production and poplar characteristics and to develop different allometry models between different organs and their carbon sequestration ability. The results showed that the independent DBH factor in populous alba, demonstrated high correlation against all the dependent variables. Height of trees also creates the allometric equations with average accuracy (0.30-0.81) against all the dependent variables. The crown diameter in dependent variable almost creates weakest equations. The result also indicated that there is no significant difference among equations of different planting spaces. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

کلیدواژه ها | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

Allometric equation؛ Populus Alba؛ non-linear regression؛ CO2؛ Greenhouse gases | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

اصل مقاله | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

Shahraji^{1}*,Y. Iranmanesh^{2}
(Received: Dec. 05.2014. Accepted: May. 11.2015)
Carbon sequestration into plants biomass, especially in fast growing trees is an easier and economically way for dropping off CO2 from atmosphere. This study was carried out in order to investigate above-ground biomass of white poplar (populous
Continuous measurement of the concentration of the greenhouses of carbon dioxide from 1958 to the present years shows a big increase in the concentration of this gas from 315 Poplars and their hybrids have displayed the capacity for rapid biomass accretion (Anderson
The study area was located at poplar research station and fast growing trees of Agriculture Research Center and Natural Resources (East longitude of 51° 6' 7"and North latitude of 31°55' 1.7") in Chaharmahal and Bakhtiari Province, in west of Iran. The mean annual rainfall is 600-700 mm and station average temperature is 11 ° C.
Four areas with different planting density were selected from 10 years old
According to DBH measuring, trees were divided to 10 diameter classes. From four different planting densities, 40 trees were selected from all diameter classes randomly. The selected trees for cutting had a uniform distribution in different diameter classes.
Selected trees were cut and divided into various components including the trunk, branch (more than 1 cm-diameter), twig (branches less than 1 cm diameter) and leaf (Sohrabi & Shirvani, 2012). The wet mass of each tree component was measured in the field. The leaf and twig samples were dried at 75 º C for 24 hours. The trunk and branch were dried at 80 º C for 48 hours. Then all components were weighted in order to estimate moisture content. Equation (1) was used to determine the components dry weight (Bakhtiarv & Sohrabi, 2012).
WDC = WDC is dry weight of each component of the tree. WFc is wet weight of each tree. WDs dry weight of each sample. WFs is wet weight of each sample.
Data normality was examined by Kolmogorov–Smirnov test. Regarding data normality, allometric relations modeling was conducted using power regression by least squares method. Past studies, have been showed that the power non-linear regression model provide the best results among allometric equations to different trees, shrubs and herbaceous species by the equation Y=b All data were analyzed using the SPSS-version 19 and Minitab-version 16.
In 0.5×0.5m planting space, the tree DBH with 0.85 to 0.97 coefficient factors had highly correlation with other organ’s biomass, and tree height with 0.5 to 0.81 coefficient factor, had fairly good correlation with other organ’s biomass, while tree crown with 0.3 to 0.6 coeffcient factors had low correlation with other organ’s biomass. The results of different component biomass are shown in Table1. Correlation between height and branch skin was not significant in 1×1m planting density, but all other in-dependent variables had significantly correlation to the other organ’s biomass. The results of allometric equation of DBH, height and crown diameter with other tree organs biomass are shown in Table2.
Estimated- biomass model between crown diameter to trunk weight, trunk skin, leaf, branch and branch skin, was not significant in 2×2mplanting density, but other in dependent variable had significantly correlation to different tree organ’s biomass. The results of allometric equation of DBH, height and crown diameter with other tree organs biomass are shown in Table 3.
*** Highly significant, (99.9), significantly high (99), significant (95) and ns no significant.
*** Highly significant, (99.9), significantly high (99), significant (95) and ns no significant.
In 4×4m plantation spacing, allometric equation of all in-dependent variables to tree component biomass, showed significant correlation. Results showed that DBH with 0.85 to 0.96 coefficient factor had highly correlation to the
Other tree organ’s biomass and other two independent variables (height and crown diameter) with 0.5 to 0.86 coefficient factor had significant correlation to other tree organ’s biomass. The results of allometric equation of DBH, height and crown diameter with other tree organs biomass are shown in Table4.
*** Highly significant, (99.9), significantly high (99), significant (95) and ns no significant.
*** Highly significant, (99.9), ** significantly high (99) and * significant. (95).
Carbon sequestration into plant biomass is an easiest and economically most practical way for dropping off CO2 from atmosphere (Parsapour
Highly correlation between tree DBH and the biomass of different organs of | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

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