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Estimation of aboveground tree carbon stock using SPOT-HRG data (a case study: Darabkola forests)

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Journal of Forestry Research 2017年第6期28卷 1172-1179页

作者： Masoumeh Fatholahi Asghar Fallah Seyed Mohammad Hojjati Siavash Kalbi Department of natural resource Sari University of Agricultural Sciences and Natural Resources SariMazandaran 48151 Iran

Forests are among the most important carbon sinks on earth. However, their complex structure and vast areas preclude accurate estimation of forest carbon *** sets from forest monitoring using advanced satellite imagery are now used in international policy *** sets enable tracking of emissions of COinto 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 *** 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.

关键词： Aboveground carbon stock Support vector machine SPOT-HRG Darabkola

Estimation of conservation value of myrtle(Myrtus communis)using a contingent valuation method:a case study in a Dooreh forest area,Lorestan Province,Iran

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Forest Ecosystems 2016年第1期3卷 26-36页

作者： Neda Amiri Seyed F.Emadian Asghar Fallah Kamran Adeli Hamid Amirnejad department of forestry sari agricultural and natural resource universitySariIran department of forest sciences gorgan agricultural and natural resource universityGorganlran department of forestry college of natural resourcessari agricultural sciences and natural resources universitySariIran department of forestry faculty of agriculturaluniversity of lorestanlorestanIran department of agricultural economics sari agricultural and natural resource universitySariIran

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 （VVTP） for myrtle conservation. The VVTP was estimated with a Iogit 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.

关键词： Conservation value Myrtle Contingent valuation method Double Bounded Dichotomous method Logit model

Soil and water conservation practice effects on soil physicochemical properties and crop yield in Ethiopia:review and synthesis

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Ecological Processes 2022年第1期11卷 206-221页

作者： Endale Bekele Jiru Habtamu Temesgen Wegari College of agriculture and natural resource Dilla UniversityDillaEthiopia College of agriculture and natural resource Bonga UniversityBongaEthiopia

Background:Land degradation is an urgent agenda that requires great effort and resources to *** worsens soil components through disrupting ecological functions and threatens agriculture *** overcome it,different soil and water conservation(SWC)practices have been undertaken in numerous parts of *** paper aims to review the effects of SWC practices on soil physicochemical properties and crop *** were collected from secondary sources via a computer library using various databases based on developed *** collected data were organized,categorized,and analyzed through descriptive *** mean difference of selected soil physicochemical properties obtained from treated and untreated farmland was tested using paired *** influencing crop yield on treated farmland were determined by a multiple linear regression ***:SWC practices influenced the soil physicochemical properties and crop yield either positively or *** mean values of available phosphorus(10.6 ppm,8.7 ppm),total nitrogen(0.5%,0.4%),soil pH(6.0%,5.8%),soil organic matter(4.4%,3.8%),and soil organic carbon(2.2%,1.8%)were on treated and untreated farmland under physical SWC practices,***,the mean values of these variables were higher on treated farmland than untreated farmland under both biological and integrated SWC *** mean value of bulk density was higher on untreated farmland than treated one and statistically significant under all SWC *** juu and stone-faced soil bund constantly increased crop yield,whereas soil bund and stone bund did ***:Proper implementation of SWC technologies through integrating physical and biological measures will boost the effectiveness of the practice in restoring soil physicochemical properties and improving crop ***,government due attention paid for land resources management in Ethiopia,whereby the annual SWC and tree planting campaign und

关键词： Land degradation Soil and water conservation Crop yield Soil physicochemical properties

Impact of land-use management on nitrogen transformation in a mountain forest ecosystem in the north of Iran

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Journal of Forestry Research 2013年第1期24卷 115-119页

作者： Maryam Asadiyan Seyed Mohammad Hojjati Mohammad reza Pourmajidian Asghar fallah sari Agricultural Sciences and natural resources university Sari-Iran.

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 （5 cm） 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 NH4 ＋-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.

关键词： soil quality net N mineralization nitrogen dynamic land use Hyrcanian forest Alandan.

Use fuzzy interface systems to optimize land suitability evaluation for surface and trickle irrigation

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Information Processing in agriculture 2019年第1期6卷 11-19页

作者： Yaser Hoseini Moghan College of agriculture and natural resource University of Mohaghegh ArdabiliArdabilIran

In this study fuzzy logic system was used for optimization parametric evaluation system in surface and trickle *** study was performed on a surface area of 5175 ha in fathali region located in Ardabil province of *** was indicated that for trickle and surface irrigation respectively an area of about 2941.35 ha(56.77%)and 159.81 ha(3%)of the lands is“highly suitable”and an area of about 246.43 ha(4.7%)and 312.69 ha(6%)is“moderately suitable”.About 797.1 ha(15.4%)and 2744.17 ha(53.02%)were respectively“marginally suitable”for trickle and surface irrigations.“Currently not suitable”suitability included about 737.58 ha(14.2%)and 1746.05 ha(33.7%)and“Permanently not suitable”suitability matched 458.54 ha(8.86%)and 212.28 ha(4.1%)in the zone under *** to the results,there is a major difference between the“highly suitable”lands obtained through the two methods and the area of“highly suitable”lands in the trickle method is about 18 times of the area of“highly suitable”obtained through the surface irrigation *** a result,considering the gradual changes of soil parameters,fuzzy evaluation leads to more accuracy compared to the parametric non fuzzy *** and large,it can be said that fuzzy method,shows higher qualities about the suitability of lands for trickle irrigation.

关键词： Surface irrigation Evaluation of lands Trickle irrigation Optimization

Temporal trends of hydro-climatic variables and their relevance in water resource management

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International Journal of Sediment Research 2021年第1期36卷 63-75页

作者： Karim Solaimani Mahmoud Habaibnejad Abdollah Pirnia GIS Centre University of Agricultural and Natural Resources of Sari Department of Watershed Management University of Agricultural and Natural Resources of Sari

Identification of temporal changes in hydrological regimes of river basins is an important topic in contemporary hydrology because of the potential impacts of climate change on river flow *** this purpose,long-term historical records of rainfall(P),runoff(Q) and other climatic factors were used to investigate hydrological variability and trends in the Tajan River Basin over the period *** evaporation(E),rainfall variability index(d),evaporation ratio(CE) and runoff ratio(CQ) were estimated from the available hydroclimatological ***-Kendall trend analysis and nonparametric Sen’s slope estimates were performed on the respective time series variables to detect monotonic trend direction and magnitude of change over *** variability index showed that1973 was the wettest year(δ=+2.039) while 1985 was the driest(δ=-1.584).Also,decades 69-78 and89-98 were recognized as the wettest and driest decades *** gradient of variation of climatological parameters showed that during the study period,all three parameters of rainfall,evaporation and runoff have decreased and the variations of rainfall and evaporation were significant at the95% *** of hydrological changes due of dam construction(1999) showed that the amount and annual distribution of discharge were completely different pre and post-dam *** decreased in high water months and increased in low water months to meet water supply demands,especially for *** relationship between temperature and rainfall trends is compared for three stations in Mazandaran Province(Gorgan,Babolsar and Ramsar) from 1956 to 2003 and nine other stations with different statistical periods of 19-36 years,relating trends to northern hemisphere and global *** in temperature were accompanied by decreases in rainfall,and vice *** trends were not observed in northern hemisphere and world scales,where temperature increases are accompanied b

关键词： Climate change Human activity Hydroclimatological Trend analysis Mazandaran Tajan basin

Factors that influence the implementation of sustainable land management practices by rural households in Tigrai region, Ethiopia

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Ecological Processes 2019年第1期8卷 183-198页

作者： Haftu Etsay Teklay Negash Metkel Aregay Department of Agricultural and resource Economics College of Drylands Agriculture and Natural ResourcesMekelle UniversityMekelleEthiopi

Background:Sustainable land management is considered as one of the useful approaches to combat the threat of various forms of land degradation in *** this,there is scant information regarding households’decision towards the implementation of sustainable land management *** paper,therefore,looks into the determinants for the continued use and choice of the sustainable land management practices by smallholder farmers and its productivity effect in three randomly chosen districts in Tigrai region,*** study uses data from household survey and key informant *** paper employs a binary logit to analyze the determinants for the decision of continued use of sustainable land management practices,and a multivariate probit to analyze the simultaneous adoption decision of sustainable land management practices using cross sectional data collected from 230 randomly selected *** impact of sustainable land management practices was also evaluated using propensity score ***:Farming techniques,wealth status,agro-ecological variations,and plot level characteristics were found to be associated with the implementation decision of sustainable land management practices by rural ***,institutional supports and access to basic infrastructures influenced the overall continued use of sustainable land management practices and the preference of households toward these *** study also finds that the value of crop production of sustainable land management users was on average 77–100%higher than that of ***:The results of the current study confirm that the implementation of various sustainable land management practices are influenced by farming technologies deployed by rural households,agro-ecological variations,plot characteristics,and institutional *** findings also affirm that most of the sustainable land management practices are complementary to one another,and implementing two or

关键词： Continued use Determinants Plot level Productivity effect Sustainable land management practice,Tigrai

Species-specific allometric equations for improving aboveground biomass estimates of dry deciduous woodland ecosystems

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Journal of Forestry Research 2019年第5期30卷 1619-1632页

作者： Amsalu Abich Tadesse Mucheye Mequanent Tebikew Yohanns Gebremariam Asmamaw Alemu Department of General Forestry College of Agriculture and Rural TransformationUniversity of Gondar Department of natural resource Management College of Agriculture and Rural TransformationUniversity of Gondar

Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ***,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of Ethiopia have not as yet been *** study attempts to develop and evaluate species-specific allometric equations for predicting aboveground biomass(AGB)of dominant woody species based on data from destructive sampling for Combretum collinum,Combretum molle,Combretum harotomannianum,Terminalia laxiflora and *** at breast height ranged from 5 to 30 *** empirical equations were developed using DBH(Eq.1)and height(Eq.2).Equation 2 gave better AGB estimations than *** inclusion of both DBH and H were the best estimate biometric variables for ***,the equations were evaluated and compared with common generic allometric *** result showed that our allometric equations are appropriate for estimating *** development and application of empirical species-specific allometric equations is crucial to improve biomass and carbon stock estimation for dry woodland ecosystems.

关键词： Woodland Allometric equations Aboveground biomass Destructive sampling

Drought Forecasting in a Semi-arid Watershed Using Climate Signals:a Neuro-fuzzy Modeling Approach

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Journal of Mountain Science 2014年第6期11卷 1593-1605页

作者： Bahram CHOUBIN Shahram KHALIGHI-SIGAROODI Arash MALEKIAN Sajjad AHMAD Pedram ATTAROD Department of Watershed Management Sari University of Agriculture Sciences and Natural ResourcesSari 48181-68984Iran university of Tehran Faculty of Natural ResourcesKaraj 31585-3314 Iran Department of Civil and Environmental Engineering University of NevadaLas Vegas NV 89154-4015 USA

Large-scale annual climate indices were used to forecast annual drought conditions in the Maharlu-Bakhtegan watershed,located in Iran,using a neuro-fuzzy *** Standardized Precipitation Index(SPI) was used as a proxy for drought *** the 45 climate indices considered,eight identified as most relevant were the Atlantic Multidecadal Oscillation(AMO),Atlantic Meridional Mode(AMM),the Bivariate ENSO Time series(BEST),the East Central Tropical Pacific Surface Temperature(NINO 3.4),the Central Tropical Pacific Surface Temperature(NINO 4),the North Tropical Atlantic Index(NTA),the Southern Oscillation Index(SOI),and the Tropical Northern Atlantic Index(TNA).These indices accounted for 81% of the variance in the Principal Components Analysis(PCA) *** Atlantic surface temperature(SST:Atlantic) had an inverse relationship with SPI,and the AMM index had the highest *** forecasts of neuro-fuzzy model demonstrate better prediction at a two-year lag compared to a stepwise regression model.

关键词： Annual Rainfall Large-scale Climate Signals Neuro-Fuzzy Cross-Correlation Principal Components Analysis Drought