Showing 5 results for Soil
Mehdi Heydari, Ali Mahdavi,
Volume 1, Issue 1 (9-2014)
Abstract
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.
Hojat Alah Omidi, Javad Mirzaei,
Volume 2, Issue 1 (9-2015)
Abstract
Natural regeneration is the most important principle to maintain and sustain of vegetation in each region, therefore, doing the research about the relationship between natural regeneration and environmental factors can be useful for conducting a better management in these regions.Therefore, this study aimed to investigate the effects of physiographic factors and soil parameters on natural regeneration of trees and shrubs species in the forest of Baye Mountain in Eyvan city, Ilam province. Using systematic random sampling, 27 plots were implemented in the area with a total area of 900 square meters. Then environmental factors (physiographic and soil) and the number of natural regeneration were studied and measured. Correlation analysis showed that Cerasus microcarpa regeneration had positive correlation with OM and Ca and negative with EC. Regeneration of Acer monspessulanum L. had negative correlation with clay, and Amygdalus lycioides regeneration had positive correlation with silt, while there was no significant correlation between other species and other soil factors. The results showed that elevation had significant effects on natural regeneration of Cratagus pontica and Amygdalus lycioides, while the slope of gradient hadn't any significant effect on regeneration. Only, aspect had significant effects on Cerasus microcarpa regeneration, and regeneration of this species in the eastern and northwestern direction was more than other aspects.
Mehdi Heydari, Ali Mahdavi, Elham Jaferyan, Vahid Mirzaeizadeh,
Volume 2, Issue 2 (3-2016)
Abstract
Judas tree belongs to valuable species in Zagros forests. Nowadays, due to the special beauty of this species, it has received substantial attention in afforestation. In this regard, the improvement of seed germination is a suitable way to improve the quantity and quality of producing seedlings in nurseries and the establishment of forest plantation. In this study, the seed germination characteristics and seedling survival of Cercis griffithii in different soil treatments have been surveyed in the nursery of Aivan County in Ilam province. The experiment was set up as a randomized complete design with four treatments each contained 120 pots. Three seeds in plastic pots were sown in nursery soil (Control Control soil- cattle manure (5:1), Control soil- Litter (5:1) and Control soil- Cattle manure- Litter (5:1:1). According to the one-way ANOVA results, significant differences were observed between soil treatments in terms of germination rate, maximum, mean daily germination and germination energy, while there were no significant differences in other germination characteristics between soil treatments. The highest germination rate, maximum, mean daily germination and germination energy were observed in the treatment of Control soil- Cattle manure- Litter. In terms of time, seedling survival decreased from September to March. The results showed that there is a significant correlation between mean daily germination and different soil composition. In general, it can be concluded that germination and survival of Cercis griffithii can be improved using organic compounds in the nursery.
Ahmad Hossieni , Syyed Mohsen Hossieni ,
Volume 3, Issue 1 (9-2016)
Abstract
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)
Abstract
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.
