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Considering the climate change and global warming topics, importance of tree biomass and its measurement is increasing. Direct biomass measurement, especially for root section, is very costly, time consuming and difficult to implement. Usually, in such cases biomass can be estimated, using allometric equation. The aim of this research was to establish equations for estimating carbon content at above and below ground and whole tree biomass for four species, including Mulberry (Morus alba), Black Locust (Robinia pseudoacacia), Eldar Pine (Pinus eldarica) and Arizona cypress (Cupressus arizonica) planted around Mobarakeh Steel complex. For this purpose, 15 trees for each species (totally 60 trees) with appropriate diameter and height distribution, selected randomly and fell down and cut to different segments. Then the different components were separated and total fresh weight was measured at the field. Also roots of 20 trees fully excavated and after fresh weight measurement, some samples for dry weight determination were taken. Dry weight and carbon content of each sample were measured at laboratory. Allometric relationships between independent variables and carbon storage of different components and whole tree were established by nonlinear regression analysis. Overall, 96 models were derived for the four species and only eight of them were not statistically significant. The results showed that for Pine and Cypress, DBH (Diameter at Breast Height) and for Mulberry diameter at 0.3 m established models with highest coefficient of determination at all cases. For Black Locust, there was not special variable which can establish model with high coefficient of determination in all cases. For estimating the whole above- and below ground carbon storage of different organs, tree height had the highest coefficient of determination. Generally, concerning the both above and below ground biomass, modeling allometric relationships resulted in higher coefficient of determination of modeling for coniferous rather than for broadleaved species.

Carbon sequestration rate of forest trees and their spatial pattern are prominent factors which affect global carbon dynamic and can be basically applied to predict climate change. For this reason, compartments2 and 4 of district3 of Glandrood Forest were selected for this study and few disks (2 cm thick) were sampled from each felled oak tree at 2-5 m. interval of its bole. Further samplings were made from each disk at constant volumes (3x3x3 cm) and intervals (2 cm). The samples were oven dried in lab for 24 hours (105°C) in order to determine their dry density. Carbon factor was obtained directly by exposing the wood samples in the oven and was estimated, based on organic carbon/organic material ratio. Compartment3 of district3 (38 hectares) was selected as a control due to its undisturbed and virgin characteristics, to determine carbon sequestration of the oak trees and their spatial pattern in relation to the physiographical units. After that, 400 m2 sampling plots were allocated in the compartment, using the random systematic method at 100 m. grids, then diameter at breast height and total height of the aimed trees were measured. Carbon sequestration was estimated, using the volume x dry density x carbon ratio equation. The results of one-way Anova analysis showed that although there was significant difference between the dry wood density values at different intervals, with respect to pith to periphery (bark) of cross-section of disks (P 0.05). As the average value of oak wood dry density is 0.81± 0.0083 g.cm-3 and average carbon factor is % 57.37 ± 0.108, so according to the results of Paired-Samples t test, the values of calculated carbon sequestration were significantly more than the estimated values (P 0.05) which indicates that the spatial pattern of carbon sequestration values in the oak bole trees at the aimed study area were not associated with the environmental physical affects.

Background and Objectives: As a green fuel and environmentally friendly energy, biodiesel has recently attracted much attention and efforts are ongoing to optimizing biodiesel production from microalgae’s. The aim of this study was to determine the appropriate method of dewatering and drying biomass and selecting a suitable organic solvent for extraction lipids from biomass. Materials and Methods: After culturing Nannochloropsis Oculata in Gillard F/2 medium and reaching at the end of the stationary growth phase, algal biomass was separated from aqueous by centrifuge and drying in three methods: fore, air-dried and lyophilized. Lipid extractions of each sample was performed using soxhlet apparatus and three solvents including diethyl ether, n-hexane and n-pentane. At each stage, the quantity and quality of the extracted lipids was determined by gas chromatography. Results: In all three drying methods, palmitic acid and palmitoleic acid were significantly the main fatty acid composition of microalgae. The fatty acid composition of palmitic acid extracted by diethyl ether was significantly more than the other two solvents. Maximum production of triglyceride was observed in air dried and lyophilized (using diethyl ether solvent) microalgae as 75.03 and 76.72 % of fatty acid respectively. Conclusion: The use of lyophilized method for dewatering and drying of biomass and diethyl ether as solvent for the extraction of lipids from biomass yielded more compared with other methods studied in this paper and would be more efficient in research works related to the production of biodiesel from microalgae’s lipid.

This study was carried out to evaluate the effects of drought stress on 12 genotypes of vetch (Vicia dasycarpa) at the experimental field of Agriculture and Natural Resources Center of East Azarbaijan Province during 2003. Field trial was conducted as a spilt plot design based on randomized complete blocks with three replications. Drought treatments (normal, medium and severe stress conditions) were included in main plots and the genotypes were allocated in subplots. During the growing season, plant height, pod length, pod width, number of grains per pod, 1000 grain weight, number of pods per plant, number of grains per plant, number of axillary branches, harvest index, biomass and grain yield were measured. Drought stress effected all traits (except number of grains per pod) significantly. Greatest amount of reduction in value due to water stress belonged to grain yield and biomass. Number of pods per plant and number of grains per plant were affected by drought more than other yield components. However, the adverse effect of water stress was not similar for all genotypes and there were significant genotype by environment interaction for important characters such as biomass, grain yield, number of pods per plant, number of grains per plant and plant height. Evaluation of the genotypes based on drought tolerance indices (STI and TOL) indicated that under medium water stress environment the genotypes 9 (from Italy) and 7 (from Turkey) showed better drought tolerance performance in terms of grain yield. Regarding biomass, the genotypes 3 (from Italy) and 6 (from Australia) were recognized as the most appropriate genotypes for hoth medium and severe drought stress conditions.

Iran is located in the dry belt of the earth and is predicted to face water stress in the next half-century. Currently, the area of sugarcane cultivation in Khuzestan is over 85,000 hectares and due to the high water needs of sugarcane and drought conditions, optimization of water consumption and irrigation management is necessary to continue production. Therefore, in this study, the values of soil moisture, canopy cover, biomass yield in five treatments and irrigation levels (start of irrigation at 40%, 50%, 60%, 70%, and 80% soil moisture discharge) during 2 planting dates in the crop year 2015-2016 on sugarcane cultivar CP69-1062 in Amirkabir sugarcane cultivation and industry located in the south of Khuzestan was simulated by AquaCrop model. The measured data on the first culture date (D1) and the second culture date (D2) were used to calibrate and validate the model. The results of NRMSE statistics in canopy cover simulation in calibration and validation sets with values of 2.1 to 15.6% and 3.8 to 18.3%, respectively, and in biomass simulation with values of 6.2 to 15.2%, and 9.5 to 12.6%, respectively and coefficient of determination (R2), range 0.98 to 0.99 indicated that the high ability of the AquaCrop model in simulation canopy cover and biomass yield. whereas, the values of NRMSE of soil depth moisture in the calibration and validation sets ranged from 11.6 to 23.8, and 12.2 to 22.7, respectively, with a coefficient of determination (R2), 0.73 to 0.96 (calibration) 0.8 to 0.93 (validation) showed less accuracy of the model in the simulation. The best scenario is related to the third proposal that water consumption, water use efficiency, and yield are 1710 mm, 1.53, and 42.27 tons per hectare, respectively, which shows a reduction in water consumption of 360 mm.