Gorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101Dynamics and Structural characteristics of a natural unlogged oriental beech (Fagus orientalis Lipsky) stand during a 5-years period in Shast Kalate Forest, Northern Iran107129168910.22069/ijerr.2014.1689ENMojtabaAmiriAuthor and Reviewer (corresponding)RaminRahmaniAuthorKhosroSagheb-TalebiAuthorHashemHabashiAuthorJournal Article20130520Investigation on structure and dynamics of natural forest ecosystems is an important issue for silvicultural decisions. The aim of this study is to analysis dynamics and structure of a beech stand during 5-year period in the Shast Kalateh forest in the Caspian region, North of Iran. Data were collected from a 16.9ha permanent research plot established in a natural unlogged stand in 2006. All living trees with a diameter at breast height of ≥7.5cm were measured. The analysis of results showed that the total living stand density and volume was fluctuated between 302 and 287Nha-1 and 504 to 472m3ha-1 over a 5-year period, respectively. Results also showed that the total density of deadwood increased from 21 to 27.7Nha-1 over the 5 years. During the study period the volume of died trees was 15.3m3ha-1, that was equal to 3% mortality compared to the living trees volume in 2006. The maximum proportion of stem numbers were found in the small diameter class (≤30cm), whereas the maximum volume of trees was found in the largest diameter class (>75cm). Another remarkable change was related to the amount of total volume in the diameter class (35-50 cm), which was 37.4 and 40.3 m3ha-1 from 2006 to 2011, respectively. The results showed that the highest mortality rate happened among young trees with diameter ≤30cm. It can be concluded that Shast Kalateh forest as a part of beech forests is passing through a degradation phase, due to the significant number and volume of dead wood.https://ijerr.gau.ac.ir/article_1689_1c7439b69ddaff854fd8b7394a85bd63.pdfGorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101Effects of Sandy Desertified Land Reclamation on Soil Carbon Sequestration (Key Study: Kerman province)131140169010.22069/ijerr.2014.1690ENHamid RezaAsgariDept. Arid Zone Management
Faculty of Watershed and Arid Zone Management
Gorgan, Gorgan University of Agriculural Sciences and Natural ResourcesJournal Article20121028Desertification leads to decrease in the ecosystem C pool and attendant reduction in Soil Organic Carbon (SOC). Reclamation of sandy land in arid and semi-arid has a high potential to increase carbon sequestration and improving soil quality. Our objective as to examine the changes in the soil carbon sequestration and soil properties of two soil layers (0–20 and 20-50 cm) under two types of reclamation management. Our study was in the desertification control sites in shifting sand land of Kerman province in Iran. In this region Atriplex canescens and Haloxylon ammodendron species have been planted for erosion control. According to the research objectives, were taken 24 samples of soil from each depth (under canopy cover and control sit) whit Systematic – random method. Soil carbon sequestration was determined by Walkley–Black method .The results showed that the reclamation of severe sandy desertified land resulted in significant increases in soil organic carbon (SOC), SOC concentration caused by the planting Haloxylon and Atriplex species, increased by 16.2 and 18.1 ton/ha compared to the control site (shifting sand land) after 20 years. The rate of carbon sequestration in soil in the Atriplex area was more than Haloxylon area. Therefore, it is concluded that A.canescens had better performance in desert rehabilitation project to carbon sequestration in sandy land of Jupar area than H.ammodendron.https://ijerr.gau.ac.ir/article_1690_995d9759df51d14548261fc8d29811c9.pdfGorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101Relationship between topography, land use and soil moisture in loess hillslopes141165169110.22069/ijerr.2014.1691ENVahedberdiSheikhEmielVan LoonUniversity of AmsterdamLeoStroosnijderWageningen UniversityJournal Article20121203The relationship between topography, land use, and topsoil moisture storage is investigated for a small catchment with undulating deep loess hilslopes in the south of the Netherlands. For a period of 10 months, soil moisture profiles have been measured weekly at 15 locations throughout the catchment. A Generalized Additive Model was employed to find relationships between the various factors influencing soil moisture. It defines a water balance as a sum of non-linear components. The water balance is applied to our data at various spatial (catchment, response unit, hillslope and plot), and temporal (monthly, weekly and daily) scales. Each of the water balance components is parameterized as a function of topographic variables, land use variables, weather variables and antecedent soil moisture. The model framework is hierarchical: it starts at the coarsest spatio-temporal resolution, the water balance components found here act as constraints when identifying models at finer resolutions. It turns out that the importance of land-use variables varies considerably with temporal resolution. At coarse resolutions land-use is unimportant, whereas at finer resolutions it becomes more relevant. Land use is equally important over all spatial resolutions (response unit and finer). Topography is mostly relevant at the plot scale. The water balance terms become increasingly non-linear at finer scales. Evapotranspiration depends mainly on reference evapotranspiration and crop cover. Drainage to deeper layers depends mainly on soil moisture and to a lesser extent on topography. Lateral transport is weakly dependent on topography. It appears that autoregressive components become increasingly important at finer temporal resolutions.https://ijerr.gau.ac.ir/article_1691_aa0fc980337ffd309ab7550200d7551d.pdfGorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101Stocks status of kilka in Iranian waters of the Caspian Sea167180169210.22069/ijerr.2014.1692ENHasanFazliCaspian Sea Ecology Research CenterJournal Article20130223The present study considered the situation of kilka stocks in last decades by using overfished biomass threshold, fishing effort ratio and fishing mortality proxy during 1991-2010. The CPUE index of anchovy and mixed-species of kilka indicated an undepleted from 1991 to 2000. In 2000, the CPUE ratio declined to close to the “in danger” region, and subsequently collapsed to “overfished” region from 2001 to 2007 for both of anchovy and mixed-species of kilka. The CPUE ratios of common kilka have been in an overfished state during 1991-2003. During 2008-2010 the biomass increased and the CPUE ratio of common kilka and mixed-species moved to not overfished region. The control rule of anchovy kilka showed that overfishing was occurring from 1998 to 2010, ovefishing-effort was exceeded the overfihing threshold (MFMT) by 12-66%. The trajectory of the phase-plot of biomass proxy (CPUE ratio) and fishing mortality proxy (Effort ratio) of anchovy kilka showed that the status of the fishery of anchovy kilka has generally declined since 1998 collapsed to lowest level in 2010. The trajectory for common kilka has generally increased since 1991 which it was closed to the fisheries management target in 2007. In conclusion, in the new condition, common kilka is the main species in the Caspian Sea. For stock recovery of anchovy kilka, the catch of kilas must be restricted during reproduction periods, and also, a coordinated international effort is needed.https://ijerr.gau.ac.ir/article_1692_55d71d81059dee483946cf000b9ab2f8.pdfGorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101Study of carpinus betulus dieback distribution using topographic factors181189169310.22069/ijerr.2014.1693ENKambizTaheri AbkenarGuilan UniversityFarzanehSedighiGuilan UniversitySanazMahmoudiGuilan UniversityJournal Article20130103The expanding phenomenon of dieback is caused by the reaction of trees against the harmful biotic and a biotic factor that lead to dying of shoots and branches of trees from upper crown to lower crown. This phenomenon spreads throughout the leaves and branches and all parts of the plant and may finally lead to the death of the plant. This study aimed to identify species dieback especially Carpinus betulus and to study the spread of dieback in this species using topography factors in series one of shastkalate forest. In the studied area, a statistical network with dimensions of 600*800 m was randomly and systematically designed (network of plots) and cluster sampling with six trees was applied (in every plot). Topographical factors (altitude, slope direction and percentage) in each plot were taken. Analyzing the data indicated that 28% of the total stands suffer from different degrees of dieback among which 22% belong to the carpinus betulus species. The percentage of dieback stands of this species in different classes of height had no meaningful difference, but it was more in western slope and gradient of less than 20%.https://ijerr.gau.ac.ir/article_1693_04e40dc3752ce762aae10cb7a8ff97b9.pdfGorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101The effect of trout farm effluents on the water quality parameters of Zaringol Stream (Golestan, Iran) based on NSFWQI and WQI indexes191201169410.22069/ijerr.2014.1694ENZohrehMazaheri KohanestaniFaculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural ResourcesRasoulGhorbaniFaculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural ResourcesAbdolmajidHajimoradlooFaculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural ResourcesAsgharNaeimiFaculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural ResourcesJournal Article20121226The aim of this study was to assess the potential impact of Trout farm effluents on water quality of Zaringol stream based on NSFWQI and WQI indexes. Some physicochemical water quality parameters were measured from 14 point during December 2009 to September 2010 seasonality. The average value of NSFWQI is 53.21 and it shows spatial and temporal variation. The maximum value or best water quality condition (74.5) and minimum value of NSFWQI or the worst condition (50.93) belongs to point 1 and 2 respectively. Results show that the maximum and minimum of its values are estimated for autumn and spring which are 59.62 and 53.82. Similar to the NSFWQI, the WQI index changes between different stations. Point 2 and 8 have the lowest value (0.76), point 7 has the highest (1.01) one and the mean value is 0.88. Although the temporally variations of WQI are low, the highest value is calculated for summer (0.94) and the lowest one (0.81) referred to autumn Therefore, water quality status of Zaringol stream is average and need to change strategies of management and sanitary programs. It seems that effluents entering from Trout farms were located around Zaringol stream (point 2 and 8) and increasing those activities in spring and summer are reasons of the decline in water quality especially in these points. It is necessary to manage the production rates and use of wastewater treatment methods based self-purification power of Zaringol stream and environmental standards to avoid the future risks.https://ijerr.gau.ac.ir/article_1694_64001459704dc15c8ebeeefd56d43f96.pdfGorgan University of Agricultural Sciences and Natural ResourcesEnvironmental Resources Research2783-48321220140101Understorey bird responses to the edge-interior gradient in an isolated tropical rainforest of Malaysia203232169510.22069/ijerr.2014.1695ENHosseinVarasteh MoradiCORRESPONDING AUTHORMohamedZakariaSECOUND AUTHORScott. K. RobinsonTHIRD AUTHORJournal Article20121025Forest fragmentation results in a loss of forest interior and an increase in edge habitat. We studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a 1248-ha lowland rainforest patch in peninsular Malaysia. Birds and environmental variables such as vegetation structure and litter depth were detected within a 25-m radius of each of 93 sampling points distributed throughout the forest. Species composition differed along the edge-interior gradient at the guild and species level, although only a few species were entirely confined to either edge or interior habitat. Based on bird-habitat associations along the edge-interior gradient, two groups were distinguished. Abundance of the edge-specialist group, mainly foliage-gleaning insectivores and insectivore/frugivores, was positively correlated with ground cover, light intensity, shrub cover, temperature, and percent of shrub cover between 0.5 and 2 m height. Some of these edge-preferring species also occurred in the matrix surrounding the patch and were extremely abundant, which may create problems for forest species. In contrast, the interior-specialist group, mainly terrestrial insectivores, avoided the forest edge and was positively associated with humidity, canopy cover, number of dead trees, percentage of litter cover, and depth of the litter layer. From a conservation perspective, forest remnants in the lowlands of Peninsular Malaysia that have a deep leaf litter layer, a dense canopy cover, high number of dead trees, and high relative humidity are able to support regionally significant understorey bird species that are sensitive to edge effects. As such these forests have important conservation value.https://ijerr.gau.ac.ir/article_1695_86fc3980e81e52463d8541e2e595176f.pdf