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Showing 4 results for Watershed Management
Mehdi Heydari, Ali Mahdavi,
Volume 1, Issue 1 (9-2014)
Despite the implementation of watershed management projects over a wide area has long history in Iran, but the quantitative assessment of these projects have been neglected. In this study, the effects of watershed management project of Kalan-e-Eyvan in Ilam province from ecological point of view (the relation of vegetation composition with physicochemical soil properties) were investigated. In doing so, four status of watersheds were assessed, namely, status A (implemented area after 5 years in 2010), status B (the witness area without implementation of plan in 2005), status C (the witness area without implementation of plan in 2010) and status D (the area A before implementation of the project in 2005). The results showed that plant species in four statuses were classified into two groups based upon Canonical Correspondence Analysis (CCA) and the species in A, B and C statuses were mostly perennial classified as climax stage species. The results showed a floristic similarity between planed and control areas after 5 yearsturned out. There werea clear differences regarding to vegetation composition, nutrient and saturation percentage (SP) between the area after and before plan implementation. The results of one-way ANOVA indicated significant differences regarding to diversity and richness between four statuses. The results of Duncan-Test showed that the implementation of watershed management project has caused increasing in diversity and richness in planned areas in comparison with non-planned watershed management ones.
Ahmad Hossieni , Syyed Mohsen Hossieni ,
Volume 3, Issue 1 (9-2016)
Oak decline is a complex phenomenon that oak forests are faced with it across the world and Iran. Shalam forested area located in north of Ilam province was selectedto determine the role of topographicand some edaphic factors in tree mortality happened in Persian oak forests. The study region was divided into 20 homogeneous topographic units. Within each homogeneousunit,three 0.1-haplots were randomly-systematically established for measuring the rate of tree mortality and oneprofile was prepared for characterization ofsome physical and chemical soil characteristics (texture, moisture content, TNV%, OC% and N for each soil layer, and soil depth). In each plot,diameter at breast height (DBH), maximum and minimum crown diameters, crown dieback percent, origination and form of trees and shrubs for all species and site variables weremeasured. Results showed that 15.7% of forest stock had reduced while 97.65% of it belonged to Persian oak species. The results of multiple linear regression and RDA showed that tree mortality was significantly affected by elevation and aspect, but not by slope. The highestrate of tree mortality was observedin high elevation and south and west aspects. Also the results of multiple linear regression and RDA showed that tree mortality was significantly affected by soil depth and texture. So, the highestrate of tree mortality was observed in soils with less depth, less sand% and more silt%. It was concluded that topography and soil have effective role in tree mortality and its expansion across Zagros forests. Identifying the critical conditions in terms of topography and soil in these forests can help and be useful in the management of tree dieback.
Masoud Nejabat, Mohammadreza Negahdarsaber,
Volume 3, Issue 2 (3-2017)
Background and objectives: Familiarity with the appropriate soil conditions for Pistacia atlantica leads to improve and develop forest vegetation cover in Zagros zone. The main aim of this research was investigate suitable soil characteristics ranges for natural growth of this species in Fars province.
Materials and Methods: Field studies and soil sampling was done based on network sampling (20×20 km grid) in wild pistachio forests of Fars province with crucified pattern. The filed study showed mountain and hilly land are the main land types that pistachio species have placed on them. These land types include the displacement of rock, stone and gravel as high and low soil depth with moderate to severe water erosion.
Results: Main physical and chemical properties measurement of soil samples showed that the only limiting growth factor has been the low soil depth. The low effective soil depth and light soil texture are the most important limiting factor on soil moisture storage ability (from rain). This deficiency, transition from drought or very dry periods (resulting from an undesirable distribution of rain) makes it difficult. Statistical analysis methods based on principal component analysis (PCA) and cluster analysis (CA) shows that wide ranges in soil characters, even up to about 40% differentiation in the measured properties do not make restrictions for pistachio Natural growth. Ecologically, Pistacia atlantica is a drought-tolerant plant. Wild pistachio (Pistacia atlantica) is one of the high resistance species in wide range of soil condition (soil characteristics) and this feature (desirable survival) make it favorite for Zagros forest rehabilitation.
Conclusion: Land and grazing management (land use planning), along with watershed management practices can conserve and improve soil and environment of wild pistachio habitats of the Zagros forests.
Ahmad Hosseini, Seyed Mohsen Hosseini,
Volume 3, Issue 2 (3-2017)
Background and objectives: Understanding the spatial pattern of tree species in their social life could have many applications from the standpoint of ecology and applied silviculture for their optimal management. For the purpose of studying the spatial pattern of Quercus brantii and Pistacia atlantica in relation to stand form and topographic factors, we selected the Manesht forested area in northern Ilam.
Materials and methods: In this research, 75 sample plots (with 2000 m2 area) were chosen, using systematic random sampling method within the study area. The variables in the plots comprised the number of tree species and topographic factors. The dispersion indices of interest included Morisita, Sstandard Morisita, Green, Lioyd and variance to mean ratio. The calculation of quantitative indices, by running the relevant computational formulas, was performed by Ecological Methodology Software. In addition, in terms of accuracy, the efficiency of quantitative indices was studied and compared. Statistical analysis of data was carried out using SPSS Software.
Results: The results showed that, for Q. brantii, the values of variance to mean ratio, Morisita and Lioyd indices and for P. atlantica, the values of Morisita, Green and Lioyd were higher in standard and coppice stands than the coppice and standard stands. For both species of Q. brantii and P. atlantica, all of the indices in question increased with increasing elevation, and the highest values of indices were obtained in 2100-2300 m a.s.l. For Q. brantii, the values of all of the indices increased with increasing slope, and the highest value was obtained in the slope class more than 60%. Moreover, for P. atlantica, the highest values of all indices were obtained in the slope class of 30-60%. The spatial pattern in classes of 0-30% and 30-60% was clumped and in more than 60%, it was regular. For Q. brantii, the values of all indices and for P. atlantica, the values of Morisita and Lioyd were the highest in the southern direction. The results of the precision study of the indices showed that for Q. brantii, the indices of Morisita and Standard Morisita and for P. atlantica, indices of Standard Morisita and Green had the highest precision.
Conclusion: It was concluded that the value of dispersion indices (especially more accurate indices) varies by environmental factors and thus changes in values could be used in forest dynamic studies and the interpretation of changes in forests.