فصلنامه گیاه و زیست بوم
پیاپی 54 (بهار 1397)

Mapping the spatial distribution of rangeland species is essential for planning and proper management of rangelands. In this study,the spatial variation of Artemisia austriaca density in the southeast faced slops of Sabalan rangelands was investigated. Overall, 151 sites were selected following systematic-random method. Then, inside each of the determined sites, five 1×1m2plots were selected at 10-meterdistances from each other along the transect. In each plot, the density of A. austriacaspecies was measured and the elevation, slop, direction, rainfall and temperature data were extracted for each site. After normalizing the data, an analysis of spatial statistic was carried out to derive spatial correlation among the collected samples. Finally, variogram and co-variogram were extracted and the best model for fitting was chosen. Based on the best fitted models and using Invers Distance Weighted (IDW), Kriging and Cokriging methods, the map of density was produced for each species. Data analyses and mapping were conducted using SPSS19, GS1 and ArcGIS10 software. Accuracy assessment of the results was carried out using cross validation and three methods including: Root Mean Squared Error (RMSE), Mean Bias Error (MBE) and Mean Absolute Error (MAE). The results showed that, after normalization, the best fitted variogram model was the exponential model (R2=0.95) and data had high spatial correlation (C/(C) =0.85). From among the spatial statistical methods, the best method was the disjunctive Cokiriging (RMSE=0.58). According to the produced maps,Artemisia austriaca are distributed on the northwest (36 to 76%), west and southwest parts of the study area with the highest amount of density. The lowest amount of density was mapped on the northeast, south and southeast (

Salvia L. is one of the largest genus of Lamiaceae which has a lot of pharmacological importance. In this study, nutlet morphology of six species of the genus Salvia L. was examined by means of stereomicroscopy and scanning electron microscopy (SEM). For so doing, nutlets were collected from different species and their morphological traits were examined. The nutlets exhibited variations in shape, size, color, and surface sculpturing. Cluster Analysis (CA) and Principal Component Analysis (PCA) were respectively used to determine the relationships between species and their characteristic traits.In the UPGMA dendrogram obtained from nutlet data, S. nemorosa and S. virgatawere placed in one cluster and the remained taxa were put in another cluster. These results are consistent with the morphological classification of these taxa. Furthermore, the results of principal component analysis (PCA) showed that the equatorial shape, size and mid-rib were the most useful and diagnostic characteristics for the separation of species.

The lake of Sanandaj dam is located within the territory of Sanandaj city,in the longitude coordinates of 46° 33' and the northern width of 55° 20', in the upstream of Banidar village and over Komasi river. The field activity of this research was seasonal and was carried out for one year from June 2015 to June 2016. Considering the size of the lake, five stations were set up in the lake. Phytoplankton was sampled from three surface layers, the middle layer, light absorbing layer and the layer near the bed of the lake.Phytoplankton specimens were immediately recorded with 4% formalin fixation (fixed) and then examined and identified under microscope with a magnification of 10X, 20X and 40X. The results of the study on the composition and species diversity of phytoplankton showed that 54 species existed in the lake. In this study, six groups of phytoplankton including: Bacillariophyta, Chrysophyta, Pyrophyta, Cyanophyta, Chlorophyta and Euglenophyta with 20, 1, 9, 6, 16, and 2 species were identified. The seasonal analysis of species diversity of phytoplankton revealed that in spring, summer, autumn and winter, respectively, 23, 25, 25 and 18 species were recorded.The highest species variation belonged to summer and autumn with 25 species. In addition, exploring the demographic changes of 6 phytoplankton groups in the lake indicated thatthe highest and lowest densities of phytoplankton respectively with an average of 3750000 ± 239793 and 127481 ± 90656 belonged to autumn and summer.

In this research, the effect of drought (water deficit) stress and manure on vegetative body weight, essential oilyield, and physiological and morphological characteristics of Dragonhead (Dracocephalummoldavica) was investigated in a strip plot experimentunder pot conditions with 15 treatments and three replicationsfollowing complete randomized block design (CRBD)in the greenhouse of Islamic Azad University of Jiroft branch in 2009. Irrigation treatment, as a vertical factor,was selected based on field capacity (FC) level, including 75, 50 and 25 percent and manure level (0 – 10 – 20 – 30 – 40 t/ha) was applied as the horizontal factor. The results showed that the effect of water deficit stress for all morphological characters was significant (p

Extreme grazing is amongst the most important destructive factors in the country. Forage production is one of the most important factors influencing the grazing capacity and is influenced by climatic fluctuations. Predicting forage production using climatic data can be helpful in determiningthe long term grazing capacity in rangelands.The study was conducted to estimatethe production and long-term grazing capacity in the stepperangelands of Abbas Abad, Taft, in Yazd province. For so doing, first, the relationship between forage production and precipitation pattern was investigated using ten-year statistics (2004-2013). After estimating long-term production,long-term grazing capacity was determined using the available forage (the usual method) and the factors affecting the grazing capacity (metabolism energy). Regression models (simple and multiple, step wise) were used to findthe relationship between the annual forage production and the precipitation pattern. According to the results, previous rainfalls (the rainfall of the past year in addition to the rainfall of the growing season) and winter rainfalls, as independent variables, have the highest correlation with the total forage production in Abbas Abad region. 0.97 of the changes in total forage production can be estimated by previous and winter rainfalls. The results of determining capacity by means of the two common methods and metabolism energy indicated that,without considering effective factors, the estimated grazing capacity procedure, as the usual method, does not guarantee the sustainability of livestock production and utilization in rangelands.

Variable area transect distance method (VAT) is a plot-less sampling method that has rarely been addressed in previous research in spite of its estimating capacity. This method makes it possible to estimate the density without the need for a long search to find the
desired tree. In the present research, after a hundred percent inventory, a total of 40 sampling points were selected following the random systematic method. In each point, 10- meter transects were searched to find and measure the third individual. Different estimators were used to calculate canopy and density per hectare. Sampling error (E %) was applied as a measure of precision (resulting from statistical equations and bootstrap technique) and the closeness of results to real data was taken as a measure of accuracy. The results indicated that the estimator proposed by Parker has the highest precision in estimating density and the estimator proposed by Morisita has the highest accuracy. No acceptable results were obtained for canopy per unit area. Generally speaking, the variable area transect method indicated the accepted error and appropriate accuracy in estimating the number of trees per hectare for the forests outside the North (20 %). As variable area transect is very fast method, one can increase sample size to achieve better precision and accuracy. So this method can be recommended for the rapid assessment of Zagros forests. Furthermore, in this research, the efficiency of Bootstrap technique for extracting the confidence intervals for distance sampling methods was demonstrated.

Containing valuable components such as thymol and carvacrol, the essential oil of Thymus spp is considered very important. The present study aimed at introducing Thymus species or accessions with advantages in the quantity and quality of essential oil production. For so doing, 72 accessions andnine different species ofThymus were cultivated in the Research Station of Medicinal Plants in Shahedieh Yazd. The aerial parts of plants were collected at 50% flowering stage and then were dried in shadow.The essential oils were extracted following hydro–distilled method by Clevenger apparatus for three hours. After determining the essential oil yield, based on the dry weight of the plant, the oil was identified and decomposed by Gas chromatography (GC) and chromatography-mass spectroscopy (GC/MS). Considering oil production per hectare, oil yield, and thymol percentage, the species were respectively classified as Thymus daenensis, T. vulgaris, T.transcaspicus, T.lancifolius, T. migricus, T. kotscyhanus, T.fedchenkoi, T. pubescens and T. transcaucasicus.

Considering the importanceof plant evaluation for obtaining substances with anti-bacterial effects, the anti-microbial activity of Leuteacupularis was investigated in this study. Plant samples were collected at the end of summer 2014 from a 2800-meter altitude of Rendan village in Tehran. The materials in aerial parts of the plant were extracted by soaking them in methanol. After that, the nonpolar material was extracted using n-hexane. The minimum inhibitory concentration (MIC) of aerial parts of the plantwere identified by broth micro-dilution method. Plant extracts were evaluated against Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa,Klebsiella pneumonia and Bacillus cereus.Cefixime was used as the standard antibiotic. Comparing the anti-bacterial results of the two samples indicated that the hexane extract has the best effect against Bacillus cereus(MIC=0.25mg/ml),Escherichia coli and Staphylococcus aureus (MIC = 1 mg/ml), and Klebsiella pneumonia (MIC = 16 mg/ml), respectively. Pseudomonas aeruginosa was identified as the most resistant bacterium against the two extracts (MIC = 64 mg/ml). The results of methanol extract evaluation showed that MIC forE.coli, St.epidermidis,St. aureus, K.pneumonia and B.cereus was 16mg/mlwhereas64mg/mlfor P. aeruginosa. Therefore, it can be concluded that the hexane extract has better anti-bacterial effects compared to methanol one.

According to World Health Organization (WHO) report, the rise and spread of antibioticresistant strains is a growing problem in many countries. Many attempts have been made to discover new antifungal antibiotics from various sources such as microorganisms, animals and plants. One of these sources is the traditional medicine, the systematic analysesin which have led to the discovery of new effective substances. Mint and nettle are important medicinal plants with various physiological activities. The purpose of this study is to evaluate the ability of these plants’ extractions to inhibit the growth of fungi that contribute to the formation of skin infections. After collecting nettle and mint from Alborz heights, they were planted and dried in shade and plant leave extractswere obtained using aqueous solvent. The extracts were concentrated in vacuum at 60 ° C. Antifungal activity of the extracts was measured using MIC and MFC in microplate. Antifungal activity against Trichophyton Mangrofusetis (PTCC 5054) and Kennis Microsporum (PTCC 5069) was measured by culturing these microorganisms in a medium containing a specific concentration of extract (tubular method). All tested microorganisms were susceptible to both extracts. From diluted peppermint solutions within the range of 50 mg/ml to 56.1 mg/ml, the last effective concentration was 3.12 mg/ml. Diluent diluted solutions were used within the range of 50 mg/ml to 0.56 mg/ml, with the last effective concentration of 25.26 mg/ml.