جستجوی مقالات مرتبط با کلیدواژه « جنگل شهری » در نشریات گروه « جنگلداری »

Urban forests play an important role in mitigating the impacts of climate change by reducing atmospheric carbon dioxide (CO2). Quantification of carbon storage and sequestration by urban forests is critical for the assessment of the actual and potential role of urban forests in reducing atmospheric CO2. With the aim of determining the most suitable urban trees for carbon sequestration, this study compared the amount of carbon stock in biomass and litter of afforested areas in Lavizan Forest Park in Tehran.

Six 40-year forest types including Pinus eldarica-Cupressus arizonica (pure coniferous), Robinia pseudoacacia-Fraxinus sp. (pure hardwood), Robinia p.-Fraxinus and Cupressus arizonica-Robinia p. (mixed) with the largest area were selected. In each afforestation type, 25 sample plots of 100 square meters were established. In each sample plot, quantitative characteristics of trees including diameter at breast height (DBH), tree height (H), height at the beginning of the crown and two perpendicular diameters of the crown were measured. Inside each main plot, litter was collected in one square meter micro-plots. As the data were normal according to the Shapiro-Wilk Test, the means of tree quantitative variables and carbon sequestration were compared using Duncan Test. To understand the influence of most important quantitative variables on sample plot distribution, Principal Component Analysis (PCA) was run in PC-ORD (ver.5).

According to the results, the maximum and minimum carbon were stored as biomass in stands of Cupressus arizonica (131.3 kg per tree) and Robinia pseudoacacia, (14.1 kg per tree), respectively. The highest and lowest carbon storage in litter belonged respectively to Pinus eldarica (1.2 tons per hectare) and Fraxinus (0.1 ton per hectare) types.

According to the result, it can be said that different plantation types have different ability to store carbon in the biomass and litter. Overall, carbon storage potential in conifers (Cupressus arizonica and Pinus eldarica) was higher than in broadleaved species (Robinia pseudoacacia and Fraxinus sp.) in the study area.

Today, social equality is more important than any issue in urban management and can affect all aspects of citizens' lives. From the perspective of social equality one of the most important goals of urban planning is access and efficiency fair of all citizens to public services. Urban Parks as an important part of urban green spaces can provide citizens with variety of environmental, social and economic products and services. The well- distributed urban parks are integral part of cities that citizen can access to and benefit from them. This project was conducted to studying spatial distribution of urban parks of Khoramabad city using network analysis and buffering,

the analysis was conducted using the maps of three districts of city and urban parks. The spatial distribution of parks in the three districts was evaluated in terms of serviceability indices including service area ratio, service population ratio, and service floor area ratio.

The results showed that per capita urban park areas for 3 districts are 1.76, 1.37 and 2.76 m2, respectively. The simple analysis buffering service area of urban parks was 1693/87 hectares which covers about 47/51% of the total city and total service network of urban parks was 845/06 hectares (approximately 23/7% of the city) that about half of servicing area of the buffering method.

the results of this study showed that city parks in Khorramabad are poorly distributed in relation to population, land use and density of development. This poor distribution must be considered in future plans in urban parks management.

We assessed the urban trees structure in Tabriz city and estimated the isoprene and monoterpenes emission using i-Tree Eco model. The results indicated that the i-Tree Eco model could be used as a successful method in Iran. Estimations of i-Tree Eco model showed that urban trees with 9.4% tree cover emitted 18428.6 and 49757.5 monoterpenes and isoprene during the year 2015. Open spaces and the ten tree species among the existing 48 species accounted for 63.3 and 92.22% of the total emission respectively. In the other hand White poplar and Austrian pin emitted the highest amount of isoprene and monoterpenes. Our results suggest that to plant the trees that emit fewer BVOCs in order to help to reduce the ozone level in cities. The results of this study could be used in proper urban environments and green infrastructure management.

Urban forests are an indicator for establishing cities and they have important aesthetic values due to environmental effects as well as providing green spaces. Trees have the most important effect on the weather of cities among green spaces and the larger the area of the forested land, the more positive outcomes would be obtained. The present study was done to compare ground survey method with Ikonos images in Google Earth Meta data for estimating various quantitative characteristics of urban forests in some parts of Sari, Iran. Using the ground survey method, we employed systematic random sampling design to estimate trees canopy cover on Jomhouri Eslami Street in Sari. The canopy of each tree was measured in two perpendicular directions and the diameter at breast height was also measured for each tree. The results of t-test showed that estimates resulting from the two methods were not significantly different (df = 118, t = 1.39). The results of regression analysis indicated that using Ikonos images (R2= 0.97) was suitable for estimating canopy area on the street. Based on our results, it can be concluded that considering the high accuracy and quick interpretation of satellite images, Ikonos images can be reliable alternatives for ground survey method in measuring tree canopies in cities with similar forest structure.