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| 1 | Mixed-effects modeling for tree height prediction models of Oriental beech in the Hyrcanian forests显示文摘Height–diameter relationships are essential elements of forest assessment and modeling efforts.In this work,two linear and eighteen nonlinear height–diameter equations were evaluated to find a local model for Oriental beech(Fagus orientalis Lipsky) in the Hyrcanian Forest in Iran.The predictive performance of these models was first assessed by different evaluation criteria: adjusted R^2(R^2_(adj)),root mean square error(RMSE),relative RMSE(%RMSE),bias,and relative bias(%bias) criteria.The best model was selected for use as the base mixed-effects model.Random parameters for test plots were estimated with different tree selection options.Results show that the Chapman–Richards model had better predictive ability in terms of adj R^2(0.81),RMSE(3.7 m),%RMSE(12.9),bias(0.8),%Bias(2.79) than the other models.Furthermore,the calibration response,based on a selection of four trees from the sample plots,resulted in a reduction percentage for bias and RMSE of about 1.6–2.7%.Our results indicate that the calibrated model produced the most accurate results. | Siavash Kalbi Asghar Fallah Pete Bettinger Shaban Shataee Rassoul Yousefpour | 2018 | Journal of Forestry Research2018，29，5： | 6 |
| 2 | Impact of land-use management on nitrogen transformation in a mountain forest ecosystem in the north of Iran显示文摘Soil inorganic N is one of the most important soil quality indexes, which may be influenced by land-use change. The historical conversion of land-use from native vegetation to agriculture resulted in sharp declines in soil N dynamics. This study was conducted to determine the soil inorganic N concentrations and net N mineralization rate in four common types of land-uses in the mountain forest area in the north of Iran, namely arable land, pine plantation, ash plantation, and beech stand. The soil samples were taken from top mineral soil layer (5cm) in each site randomly (n=6) during August- September 2010. Beech stand and ash plantation showed significantly higher total nitrogen compared with arable land and pine plantation, while extractable NH 4 + -N concentration was significantly greater in Beech stand compare to arable soils (p<0.05). No significantly difference was found in Net N mineralization, net nitrification and net ammonification rates among different land-uses. Results showed that net N mineralization and ammonification were occurred just in the soil of Ash plantation during the incubation time. Our findings suggested that conversion of Hyrcanian forests areas to pine plantation and agricultural land can disrupt soil natural activities and affect extremely soil quality. | Maryam Asadiyan Seyed Mohammad Hojjati Mohammad reza Pourmajidian Asghar fallah | 2013 | Journal of Forestry Research2013，24，1： | 3 |
| 3 | Estimation of conservation value of myrtle(Myrtus communis)using a contingent valuation method:a case study in a Dooreh forest area,Lorestan Province,Iran显示文摘Background:Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them.Myrtle is a shrub whose leaves and fruits have medicinal value and thus,if managed and harvested properly,could produce sustained economic benefits.In recent years,however,over half of the myrtle site areas was destroyed,due to inappropriate management and excessive harvesting practices.Thus,coming up with a practical harvesting approach along with identifying those factors damaging the sites,seems to be very crucial.Methods:In our investigation,we calculated the conservation value per hectare of myrtle in the Dooreh forest area in Lorestan Province.Using the Contingent Valuation(CV) and Double Bounded Dichotomous Choice(DBDC) methods,we determined the willingness to pay(WTP) for myrtle conservation.The WTP was estimated with a logit model for which indices were obtained based on a maximum precision criterion.Results:The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle sites.Average monthly WTP per family was calculated as $0.79.The annual conservation value in terms of WTP for the preservation of the myrtle sites in Dooreh was estimated as $102,525.Among the variables of the model presented,education had a positive impact,while the amount proposed for payment and family size had a negative impact on the WTP.Conclusions:Our estimate of the value of myrtle conservation should provide justification for policy makers and decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species more effectively. | Neda Amiri Seyed F.Emadian Asghar Fallah Kamran Adeli Hamid Amirnejad | 2016 | Forest Ecosystems2016，3，1： | 3 |
| 4 | 伞伐更新法对赫卡尼亚(Hyrcanian)森林系统中森林再生和林分结构的影响(英文)显示文摘研究伞伐更新法对赫卡尼亚森林系统中森林再生和林分结构的影响。在伊朗北部优势种为山毛榉(Fagus orientalisLipsky)的硬木林,采取伞伐更新法和非伞伐更新法方法设计实验区。结果表明,在山毛榉(F orientalis Lipsky)林中采用伞伐更新法处理,明显影响林下草本植物种的频度和密度。伞伐更新法处理后,林堇菜(Viola silvestris Lam.)、车叶草(Asperula odorata L.)、苔草(Carex spp.)和悬钩子(Rubushyrcanus Juz)的种频度明显增加。在对照区,树种的胸高直径(57.50±2.15cm)大于被处理区(50.67±1.88cm)的树种的胸高直径(50.67±1.88 cm),但对照区和处理区的树种的高度值相似。在1995-2005年间,波斯铁木(Parrotia persica)苗木数量增加到13.2%,而山毛榉(F orientalis)和欧洲鹅耳枥(Carpinus betulus)的苗木数量却明显减少。总之,应该利用其它育林方法,如,带状择伐作业,而不是伞伐更新法培育赫卡尼亚森林中山毛榉林。 | Mohammad Reza Pourmajidian Hamid Jalilvand Asghar Fallah Seyed Ataollah Hosseini Aidin Parsakhoo Amin Vosoughian Ali Rahmani | 2010 | Journal of Forestry Research2010，21，3： | 2 |
| 5 | Non-linear analysis of functionally graded circular plates under asymmetric transverse loadirlg显示文摘 | Asghar Nosier Famida Fallah | 2009 | Int J Non-Linear Mech2009，44，： | 1 |
| 6 | Effects of geometric design of forest road and roadside vegetation on traffic noise reduction显示文摘Geometric design of forest roads and design of their landscapes can reduce noise pollution and its harmful effects on human health. We investigated the effects of technical and biological parameters such as geometric road design and various roadside tree stands on reducing noise pollution according to the tree density and distance from roadway in Darabkola Forests, Sari, Iran. We recorded the noise generated by a car(Land Rover) relative to changes in longitudinal slope, horizontal curve radius and type of road pavement. We also measured noise levels according to roadside tree density and stand type(coniferous and hardwood) in 40 rectangular plots of three widths(25, 100 and 300 m) and 50 m length that were randomly demarcated along forest roads. The changes in noise level were recorded using a decibel meter with an accuracy of ±1.5 d B and resolution of 0.1 d B. Noise levels were higher alongside unpaved roads than alongside paved roads. There was an inverse relationship between the measured noise level and horizontal curve radius. The rate of noise level on horizontal curve with a radius less than30, 30–45 m and more than 45 m were 64.8, 70.8 and75.9 d B, respectively. The noise level increased with the increasing longitudinal slope of the road. There was a significant difference between the noise level on slopes less than 3 %(67 d B) and 3–8 %(71.2 d B) in comparison with slopes greater than 8 %(77.8 d B),(p \ 0.05). Pinus brutia L. reduced the noise level more(about 6 d B) in stands of1/3 density of mixed hardwoods within 25 m from middle of the road. Careful design of geometric properties of forest roads as well as planting coniferous trees with hardwoods is a suitable solution for reducing noise pollution. | Seyed Ata Ollah Hosseini Seyran Zandi Asghar Fallah Mehran Nasiri | 2016 | Journal of Forestry Research2016，27，2： | 1 |
| 7 | Forest attribute imputation using machine-learning methods and ASTER data: comparison of k-NN, SVR and random forest regression algorithms显示文摘 | Shaban Shataee Syavash Kalbi Asghar Fallah | 2012 | International Journal of Remote Sensing2012，33，19： | 1 |
| 8 | Estimation of aboveground tree carbon stock using SPOT-HRG data (a case study: Darabkola forests)显示文摘Forests are among the most important carbon sinks on earth. However, their complex structure and vast areas preclude accurate estimation of forest carbon stocks.Data sets from forest monitoring using advanced satellite imagery are now used in international policy agreements.Data sets enable tracking of emissions of CO_2 into the atmosphere caused by deforestation and other types of land-use changes. The aim of this study is to determine the capability of SPOT-HRG Satellite data to estimate aboveground carbon stock in a district of Darabkola research and training forest, Iran. Preprocessing to eliminate or reduce geometric error and atmospheric error were performed on the images. Using cluster sampling, 165 sample plots were taken. Of 165 plots, 81 were in natural habitats, and 84 were in forest plantations. Following the collection of ground data, biomass and carbon stocks were quantified for the sample plots on a per hectare basis. Nonparametric regression models such as support vector regression were used for modeling purposes with different kernels including linear, sigmoid, polynomial, and radial basis function.The results showed that a third-degree polynomial was the best model for the entire studied areas having an root mean square error, bias and accuracy, respectively, of 38.41,5.31, and 62.2; 42.77, 16.58, and 57.3% for the best polynomial for natural forest; and 44.71, 2.31, and 64.3%for afforestation. Overall, these results indicate that SPOTHRG satellite data and support vector machines are useful for estimating aboveground carbon stock. | Masoumeh Fatholahi Asghar Fallah Seyed Mohammad Hojjati Siavash Kalbi | 2017 | Journal of Forestry Research2017，28，6： | 0 |
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