The objective of this research was to estimate the biomass, CARBON storage and LEAF area index of hawthorn species (Crataegus aronia L.) in Sartaf forests of Ilam city. For this purpose, using random sampling method, 30 hawthorn trees were selected and variables of collar diameter, tree height, crown length and large and small diameter of the crown were measured. Then, the leaves from 1/4 or 1/8 of the crown of sample trees were collected. After drying the leaves in the oven, the dry weight of the leaves was determined. After burning a sufficient amount of dried leaves in an electric oven, the weight of organic matter and CARBON content of the leaves were obtained. The weight method was used to calculate the LEAF area index. The results showed that the average LEAF biomass, LEAF CARBON SEQUESTRATION, and CARBON dioxide absorption from the atmosphere were 99.18, 46.61, and 170.59 kg per hectare, respectively. The average LEAF area index of hawthorn species was calculated as 9.08 for each tree and 0.095 per hectare in study area. The results of allometric relationships using different regression models showed a positive and significant correlation between the variable of mean crown diameter with the variables of biomass and LEAF area index of hawthorn trees in Ilam forests. In general, the results of this research show the ability of using allometric equations to measure biomass, CARBON SEQUESTRATION, and LEAF area index of Crataegus aronia.

Forest trees are considered as most important and huge CARBON pools in the forest ecosystems and have a great influence on the reduction of CARBON emission in the atmosphere. Therefore, how to measure and estimate the CARBON stored in the trees is the main issue for ecologists. The aim of this study was to estimate of LEAF biomass and LEAF CARBON SEQUESTRATION of Cercis siliquastrum L. in Arghavan forests reserves of Ilam. For this purpose, 30 trees were selected using random sampling method and height, mean diameter of crown, number of sprout and crown length variables were measured. All leaves of 1/4 crown area were collected. After of drying, dry weighted of leaves calculated. Enough quantity of leaves was burned in electrical kiln to calculate the CARBON storage. To calculate of LEAF area index was used gravimetric method. Mean tree method was used to generalize the result to the whole forest. Based on results, mean of LEAF biomass, mean of LEAF CARBON SEQUESTRATION and mean of atmosphere CO2 absorption were 53. 55, 23. 4 and 86. 02 kg per hectare, respectively. Mean of LEAF area index in studied area was 0. 058. The results of allometric using of linear regression showed that there was a significant and positive correlation between of mean diameter of crown with LEAF biomass, CARBON SEQUESTRATION and LEAF area index variables in Ilam forests.

National Botanical Garden of Iran (N.B.G.I) consists of different native and exotic collections. Pistacia atlanticais one of the main species which has remarkable density in native collections. Woody species existed in national botanical gardens throughout the world have effective role to absorb CO2 from atmosphere. In this research, LEAF biomass and LEAF CARBON SEQUESTRATION ofPistacia atlantica was studied in N.B.G.I. At first, 30 trees were selected using stratified random sampling method and quantitative parameters were measured. All leaves of 1/4 crown area were gathered, weighted and dried. Enough quantity of leaves was burned in electrical kiln to calculate the CARBON storage. Finally, amount of atmosphere CO2 absorption was determined and allometric regressions were calculated. Based on results, mean of LEAF biomass, mean of LEAF CARBON SEQUESTRATION and mean of atmosphere CO2 absorption were 69.4, 26.2 and 96.3 kg per hectare, respectively. Diameter difference had no effect on LEAF biomass and LEAF CARBON SEQUESTRATION. There was good relationship between mean diameter of crown with LEAF biomass and LEAF CARBON SEQUESTRATION.

Today, the DeNitrification DeComposition (DNDC) is model used to anticipate soil organic CARBON (SOC) turnover and crop growth under various field management practices. Gorgan County is an important region for soybean production in Iran.  We aimed to 1) validate the DNDC model for modeling SOC dynamic in croplands under soybean cropping, 2) simulate the total topsoil (0–30 cm) SOC stocks of soybean cropping systems, 3) quantify the spatial distributions of CARBON SEQUESTRATION potential of soybean-grown croplands by Geographic Information System (GIS) techniques. In this research, soil samples were taken from 150 fields at depth of 0–30 cm before soybean cultivation and after crop harvesting. In this research, we used the site simulation type of DNDC model for simulation and denitrification/decomposition procedure. Inputs in the DNDC model included information on survey region, climate, soil, crop properties, and farmland management practices. The soil and crop properties categorized into farming management practices such as fertilization, tillage, grazing or plant cutting, and irrigation. The climatic data were obtained from one meteorological station located within the study area. To continue, crop parameters were provided based on field survey and laboratory work. Also, the soil properties (including texture, bulk density, pH, SOC, soil total N, field capacity, wilting point, hydro-conductivity point, porosity and clay fraction) were obtained from sampling sites distributed in soybean croplands of Gorgan county. Results indicated that the DNDC model can simulate the SOC values for soybean fields. Based on the results, there was correlation between the simulated and measured data for SOC. The average concentration and storage of CARBON SEQUESTRATION were as 3.97 and 1.42 Mg ha-1 for observed situation and in predicted situations obtained as 2.60, and 1.42 Mg ha-1, respectively. The highest content of SOC was related to the east, southeast, and central parts toward the south of the county, which was affected by several factors such as soil bulk density, regional climatic condition, using conservation cropping systems, improved irrigation systems, and fertilization management type. The study provided new information on how improvements in the process-based DNDC model in Iran. Therefore, it can be utilized to determine SOC change and dynamism and CARBON SEQUESTRATION potential on the regional scale.

CARBON SEQUESTRATION in soil, LEAF and litter of three tree species, viz. Eucalyptus camaldulensis, Prosopis juliflora and Ziziphus spina-christi, plantation was investigated in the Dehloran city, Iran. Results showed that the amount of sequestered C in LEAF, litter and soil was significantly different among these species. The highest amount of sequestrated C was in LEAF and the lowest amount in the soil. The results of this study would be useful for selection of appropriate species to develop green space and forest parks. Forest plantation of these areas would capture significant amounts of atmospheric C, and would be expected to contribute to soil quality and conservation.