This research aims at ecological classification and identifying diagnostic species of box tree (Buxus hyrcana Pojark) sites in Farim forests, Sari, Iran. The data were collected from 60- 400m2 sample releves in systematic- selective design (200 ´ 400 meter) by considering the indicator stand concept. Floristic data were analyzed using modified TWINSPAN and consequently, six ecological groups were classified. The results of diagnostic species analysis based on Phi fidelity index revealed that of the 77 species recorded, only 47 species had positive fidelity to presented groups (P<0.05) and therefore they were determined as diagnostic species of box tree plant communities in the study area. Detrended Correspondence Analysis (DCA) was used to represent the distribution pattern of ecological groups based on two data matrix of plant species canopy cover, full data and only diagnostic species. Comparisons of scatter plots of ecological groups along two first axes in DCA, as well as, result of cumulative traced variances in two series data (37.1% in only diagnostic species data and 26.2% in total species data) in this analysis clearly indicated that ordination of six groups based on only diagnostic species data presents more appropriate distribution pattern compared to full species data. It is concluded that application of diagnostic species may lead to improve the results of ecological group ordination in determining the effective environmental variables precisely on considered groups.

Introduction Measures of segregation help us examine many urban issues. By studying the measure of segregation, we can identify the segregation patterns. The results will be useful to provide a framework for analyzing the outcomes in decisions making process and policy effectiveness. …

Species diversity is one of complex biological concept. The reason of change in species diversity and control mechanism of this change is one of ecological salient questions. Conservation of biodiversity is final goal of natural resources management. In this research, species diversity has been analyzed in important Kurdistan's Kouhsalan habitat. On cluster sampling method, 82 plot were obtained. Clustering Analysis method was used to determine ecological species groups. Species diversity was calculated using Shannon-Wiener index, and relationship between Species diversity and soil surface cover investigated by regression analysis. Duncan's test was used to comparison of means. In this habitat, 224 species were recorded. On Clustering analysis, three groups with indicator species such as Quercus brantii, Hordeum bulbosum and Prangos ferulaceae were obtained. Shannon- Wiener index value for three groups and total area calculated 1.98, 1.95, 1.50, and 1.85, respectively. In groups and total area, linear positive model was significant between species diversity with total plant cover and herbaceous plant cover. In The first group and the third group, linear negative and positive model observed between species diversity with woody plant cover, respectively. Relationship between Species diversity and other factors was not significant. Linear positive model between species diversity with plant cover is an important guide for ecosystem management. Planning and projects should let it be so that conserves the vegetation cover, species diversity and natural ecosystem.

When the density current smashes into the lower dense fluid mass a plunge region will occur. Since the plunge depth bounds between density current and ambient fluid, determining of this point is important. In this research, the hydraulic parameters of density current and bed slope of stagnant fluid were investigated. To achieve the purpose of this research a physical model was built in the hydraulic laboratory of Shahid Chamran University (SCU) and various experiments were performed. In the experiments, the plunge depth at the different discharge of density current and density difference 6, 9, 13 and 16 kg/m3 at three slopes 8, 12 and 16% was measured. Then using Flow-3D under RNG turbulence model, plunge depth was simulated for the same experimental condition. The comparison of results obtained showed that the predicted plunge depth with Flow-3D under RNG turbulence model had a high and satisfactory accuracy. Finding showed that for the 8% bed slope, the results of RNG turbulence model 14% was more than experimental data. While, for the entire slope, the results of RNG turbulence model was predicted 10.5% in average more than measured data. Generally, the statistical investigations showed that the RNG turbulence model with satisfactory precision estimated the plunge point depth.

Context and purpose. Obtaining the private GAP standard for healthy product certification due to costs is out of reach in many small and mediumsized farms among smallholder farmers. GroupGAP has provided a much-anticipated alternative where operators and farmers' cooperatives can pay the cost of certification on a cost-sharing basis. Therefore, the purpose of this research was to explain the development strategies of GAP standard with emphasis on GroupGAP in the rice production system of Mazandaran province. Methodology/approach. Current research is qualitative and data analysis was conducted in the grounded theory method, during a three-stage process of open coding, central coding, and selective coding. The data collection tool included an in-depth and semi-structured interview with a qualitative content analysis technique, which was analyzed through Maxquda software. The statistical population of the research was 18 experts and specialists of the Agricultural Jihad Organization and managers of the Rice Farmers Cooperative Company of Mazandaran Province, who were selected by the purposeful sampling method. Findings and conclusions. After extracting the concepts of the content analysis of the interviews, 9 conceptual codes out of 30 initial codes were identified in the first stage of coding. After refining and merging, the codes were classified into 3 subcategories. These components include the group certification system, the development of publicGAP programs and the development of private GAP. In the group certificates, the two dimensions of contract system development and guaranteed purchase, the development of the cooperative company for the production of healthy products have been taken into consideration. It is recommended to strengthen the organizations and cooperatives of farmers and exporters, especially to strengthen young farmers and women organizations. Originality. Originality/innovation: Due to the importance of the GAP standard issue and farmers' problems in providing the audit fees and establishment of GAP certificate, so far, no comprehensive study has been carried out in Iran on the development of operational strategies for the establishment of GAP and GroupGAP. Therefore, the current research is an attempt to provide a useful framework in explaining GAP standard development strategies with the participation of farmers in adopting the government, private, group and cooperative certification system.

Background and objectives: Vegetation classification is an effective tool for understanding ecological relationships among species, aiding in the planning, monitoring, and management of forest ecosystems. Until now, such studies in Northern Iran have been limited to the deciduous temperate forests of the northern slopes of the Alborz range and the juniper forests in the Firouzkouh Valley on the southern slopes. However, juniper is expanding in some east-west valleys of the Haraz River (specifically, the Siah Beisheh and Punjab Amol regions), adjacent to the deciduous broadleaf Hyrcanian forests, where it forms distinct plant communities. This study presents, for the first time, an ecological classification of Crimean juniper (also known as Greek juniper, Juniperus excelsa M. Bieb. ) forests in Haraz Valley (Amol County, northern Iran), located on the northern slope of the Alborz Mountains. Methodology: A total of 54 sample plots, each 400 m², were established based on the principle of representative stands. Within each plot, all vascular plant species were visually identified and their percent cover estimated using the ordinal van der Maarel cover-abundance scale. Floristic classification was conducted using TWINSPAN based on vegetation cover, and indicator species analysis was performed using the incidence-based phi fidelity method in JUICE software. Differences in ecological units or plant communities based on topographic characteristics were analyzed using one-way ANOVA followed by Duncan post-hoc tests. Results: Five ecological units or plant communities were identified based on distinct floristic composition and topographic properties: (1) Crimean juniper-Caucasian oak (J. excelsa-Quercus macranthera Fisch. & C. A. Mey. ),(2) Crimean juniper-Horned sainfoin (J. excelsa-Onobrychis cornuta (L. ) Desv. ),(3) Crimean juniper-Judas tree (J. excelsa-Cercis siliquastrum L. ),(4) Crimean juniper-common yellow jasmine (J. excelsa-Chrysojasminum fruticans (L. ) Banfi),and (5) Crimean juniper-Alder buckthorn (J. excelsa-Rhamnus pallasii Fisch. & C. A. Mey. ). The J. excelsa-Q. macranthera group (group 1), due to its association with European-Siberian indicator species, represents a bioclimatic vegetation type on the northern slopes of the Lehar region (Punjab). The J. excelsa-J. fruticans (Group 4) and J. excelsa-C. siliquastrum (Group 3) communities are indicative of Mediterranean climatic conditions in the Siah-Bisheh and Tara regions. Meanwhile, the J. excelsa-O. cornuta (Group 2) and J. excelsa-R. pallasii (Group 5) groups, which also occur on the southern slopes of the Alborz, represent elements of the Iran-Turanian climate in the northern profile. Conclusion: The findings highlight that Crimean juniper in Haraz Valley is associated with Mediterranean indicator species such as C. siliquastrum, Spiraea crenata L., C. fruticans, Cotoneaster integerrimus Medik., Paliurus spina-christi Mill., Asparagus officinalis L., and Clematis orientalis L., forming several distinct plant communities. The presence of Mediterranean elements, along with some European-Siberian bioclimatic indicators, such as Acer monspessulanum L., A. campestre L., Zelkova carpinifolia (Pall. ) K. Koch, Celtis caucasica Willd., and Q. macranthera, emphasizes the marked contrast between J. excelsa communities on the northern and southern slopes of the Alborz. These differences underline the need for greater conservation efforts focused on these newly identified plant communities.    

In order to study of natural regeneration of persian oak (Quercus brantii) between ecological species group, Melehgavan protected area (app160 ha) of Ilam city was selected. The field data were obtained using of 67 sample plots (20m×20 m) that were located in a systematic randomized design. The attributes including some topographic and soil physico-chemical properties, trees and shrubs species type and canopy coverage, which were recorded by measuring their small / large crown diameters in each main sample plot. In order to record the herbaceous species, the Whitaker’s snail plot method was applied, which resulted in 81 m2 of the minimum plot area. Herbaceous species and number of Q. brantii regeneration in 81 m2 plots in center of each sample plot were taken. The Canonical Correspondence Analysis (CCA), Principal Components Analysis (PCA) and TWINSPAN methods were used for the site classification, determining of the relationship between species composition and environmental properties. The results showed that there were three ecological species groups in the study area. The result also indicated that there were significant different between ecological species groups in view of the higher and coppice regeneration of persian oak. The higher regeneration was greater in second group than other groups, while Coppice regeneration was higher in third ecological group. The result of Spearman correlation showed, higher regeneration had positive correlation with organic matter, total nitrogen, moisture saturation percentage, aspect and elevation. The coppice regeneration had negative correlation with total nitrogen, elevation, canopy percentage of overstory and moisture saturation percentage, but it had positive correlation with silt, Bulk density and aspect.

The effects of two isolates of Pasteuria penetrans were evaluated on root knot nematodes, Meloidogyne javanica and M. incognita-R2 on two month seedlings of Badamiriz pistachio cultivar. Two experiments were carried out with two concentrations of endospores of PA and PNG isolates (104 & 6.4×105 endospores/g soil) and cadusafos (50 Mg/1500 g soil) in a Randomized Complete Block Design in green house condition were planted in pot and treatments were applied at seedling stage (4-6 leaf). 80 days after planting the seedlings were removed from soil and all stages of nematodes were extracted and counted in roots and soils. The results showed that the PA isolate with 104 endospores/g soil was the best treatment in decreasing 88.8٪ of the final population of M. incognita-R2 in comparison with control, also PNG isolate with 6.4×105 endospores/g soil was the best treatment after nematicide in decreasing 71.2% of the final population of M. javanica when compared with control.

The effects of irrigation periods and fertilizer nitrogen rates on population of black bean aphid were studied in sugar beet fields of Isfahan University of Technology for two years. Experiments were carried out as splitplot in a complete randomized block design with four replications.Irrigation factor in three levels (100%, 75% and 50% plant water requierment in 2005 and irrigation after 70, 105 and 140 mm cumulative evaporation from class A pan in 2006) and nitrogen fertilizer in three levels (200, 150 and 100 kg/ha net nitrogen in both years) were allocated to main and subplots respectively. Pest population was assessed by weekly sampling. The highest mean population of black bean aphid was observed in 100% irrigation treatment in the first year and in irrigation after 70 mm evaporation treatment in the second year and in 200 kg/ha nitrogen treatment in both years. As irrigation cycle doubled in 200 kg/ha net nitrogen treatment, population of black bean aphid increased by 177.9 times.