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In forest ecosystems espcially riparian ones, individual trees have important effects on soil macrofauna. This research was conducted to study the effect of Populuseuphratica on soil macrofauna in Karoon River Side Forest near Shooshtar. Soil macrofauna were sampled in November 2012. Soil macrofauna under tree crown (in three crown diameter category) on parallel transects with 100 m distance from the river and eachother was sampled. Soil macrofauna in 50 cm× 50 cm plots upto 10 cm depth were hand sorted and identified to family level. Totally 342 plots were sampled. The results of correlation showed that there were negetive relationship between distance to tree crown center and soil macrofauna and this relationship was higher in the case of trees with lager crown. The results of ANOVA also showed that the crown diameter size did not have significant effect on soil macrofauna except on soil macrofauna evenness with low significant level. The correlation of distance to river with soil macrofauna showed higher abondance, richness and diversity in farther distances to the river while evenness were higher near the river. Totally it should be saied that indvidual P. euphratica wereeffective on soil macrofauna and it also should be considered the distance from riverside had massive influence on crown diamere.

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Background and objectives: Site demands and characteristics of different plant species is necessary for forest protection and restoration. Therefore, soil properties determination is one of the most important steps in plant species site demands determination. This research was conducted to understand sire demands of Lonicera nummulariifolia in Chaharmahal and Bakhtiari Province. Besides, to determine the most important soil factors affecting on L. nummulariifolia distribution.  
Materials and methods: Four sites including Gazestan (1792 m above sea level), Samsami (2210 m a.s.l.), Kohrang (2215 m a.s.l.), and Ardal (1531 m a.s.l.) were selected in Chaharmahal and Bakhtiari province. Soil samples were taken from the depth of 0-30 cm. soil physicochemical properties including soil nitrogen, available potassium, organic carbon, pH, and electrical conductivity, were determined. Besides, quantitative characteristic of trees (tree diameter, height, and crown diameter) were measured. Soil properties were evaluated using one-way ANOVA. Furthermore, principal component analysis was used to determine the most important soil variables affecting L. nummulariifolia distribution.
Results: Results of this study indicated that the tallest and shortest trees with the average of 2.26 and 1.57 belonged to the Kograng and Gazestan, respectively. Also, trees origin in the Samsami site was coppice while in the other three sites they were high stands. Soil physicochemical properties indicated that soil electrical conductivity, nitrogen and organic matter had no significant differences between studied sites. Furthermore, soil pH was almost neutral in studied sites and showed no significant differences. While, Kohrang and Gazestan had the highest significant value of potassium. The least value of potassium was belonged to the Samsami. While, the most and least values of silt belonged to the Gazestan and Kohrang, respectively. Gazestan had the least value of soil sand percent compared to the other studied sites. Conical correspondence analysis indicted that the most important factors affecting L. nummulariifolia distribution are soil organic matter, nitrogen, potassium, electrical conductivity, clay, aspects, and slope respectively. 
Conclusion: L. nummulariifolia distribution demands for sites with the higher soil nutrient and organic carbon. Also, it’s prefer neutral soil pH. In the other world soil physiochemical properties play and important role in L. nummulariifolia distribution and information about site requirements of this species could help to identify proper sites for reforestation to enrichments of Zagros forest.

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Background and Objectives: Plant ecology is the scientific study of the interactions between plants and environmental factors that determine their distribution and abundance. Ecology provides the necessary framework for an accurate understanding of vegetation dynamics and species distribution, emphasizing the essential role of vegetation within ecosystems. The biodiversity of any habitat plays a crucial role in the stability and health of the natural environment. The assessment of different plant species and their distributions allows important steps to be taken towards biodiversity conservation. Researchers use parametric distribution models, also known as abundance distribution models, to evaluate vegetation diversity and evaluate species diversity. The four main models developed by ecologists include the geometric series model, the lognormal series model, the logarithmic series model, and the broken-stick model, which are used to adjust the distribution of species diversity. The application of parametric models in riparian forests - one of the most diverse and complex plant communities in the world - has provided a new perspective on methods for assessing ecological diversity. Therefore, the aim of this study was to measure biodiversity in the riparian forests of Maroon River in Behbahan district using biodiversity distribution models.

Materials and methods: In this study, transects were laid at 100-meter intervals across the study area to record vegetation. We surveyed 79 sample plots and recorded and analyzed the percentage of tree cover, number of individuals and species composition. The TWINSPAN analysis classified the sampled plots into two ecological groups based on the indicator species Populus euphratica Oliv. and Tamarix arceuthoides Bunge, resulting in 56 and 23 sample plots, respectively. Using the species abundance data and the chi-square test for goodness of fit, we tested the fit of the Geometric, Lognormal, Logarithmic and Broken-Stick parametric models for each ecological group.

Results: The results of the chi-square test showed significant differences between the observed and expected abundance of species in both ecological groups (Populus euphratica and Tamarix arceuthoides), leading to the rejection of the parametric models. However, no significant difference was found between the distribution curve of the observed data and the lognormal distribution curve.

Conclusion: The lognormal model provided the best fit for the distribution of species abundance in both ecological groups, suggesting that these communities are heterogeneous and stable, characterized by species with moderate abundance.