فصلنامه گیاه و زیست بوم
پیاپی 47 (تابستان 1395)

The Darrehshahr region with 148,000 ha area is located in the southeast of Ilam province in the West of Iran. This study aims at introducing the floristic list, life forms, and endangered and vulnerable plant species in the forest and rangelands of Darrehshahr (Ilam province). The sampling operations were carried outduring different seasons from 2012 to 2014. First, the site boundaries were identified on the topographic map with a scale of 1:50,000.Then, by collecting the plant species of the region, the floristic list of the species was developed. The life form of the plant samples was determined using Raunkier’s method. The results indicated that there are 516 plant species in this region which belong to 312 genera and 73 families. The Asteraceae family with 53 genus and 93 species has the highest species diversity. According to Raunkier life form, 42.31% therophytes, 10.11% cryptophytes, 7% Phanerophytes, 2.14% chamaephytes, and three species of parasite grow in the region. The growth elements of the region included 30.45 % Irano-Turanian, 24.75% Irano-Turanian and Mediterranean,and 14.34% Irano-Turanian and Euro-Siberian species. The Irano-Turanian, Mediterranean,and Euro-Siberian, together with 9.23%, comprised the most frequent chorotype in the region. There are 22 endemic, fourvulnerable,sixless endangered, one endangered, and one inadequately known species in the region.

This study investigated the community structure of Chlorophyta and Euglenophyta in the southern region of Caspian Sea in Anzali port, during every month from April to October in 2012.Samples were collected from four transects of the surface, 5-, and 10-meter depth water using Rottener method. The samples were fixed by 40% formalin and after being concentratedthey were identified by means of specific keys. The physical and chemical analyses of a number of water parameters including the temperature, DO, pH, NO3, PO4, TN, total phosphorus, and EC were carried out using standard methods. According to the results, 20 species were identified 16 of which belonged to Chlorophyta and four related to Euglenophyta. The highest and lowest densities of green and Euglenoides algae were recorded respectively in August and May. Additionally, the Binuclearialauterbomiiand Euglena wangirespectively from Chlorophyta and Euglenophyta species demonstrated the highest density during the experiment.

The flora and medicinal plants of Galoochar Juniper Forest Reservoir in Kerman province were identified and introduced in this study. This reservoir is located in southeast of Kerman province in Rabor town, between 29º 18′ 42″to 29º 17′ 24″ northern latitudes and 56º 07′ 19″ to 56º 04′ 22″ eastern longitudes, with an area around 382 hectares. The altitude of the area ranges from 2500 to 3200 m from the sea level.Theaverage altitude in this region is 2850 m and the average annual precipitation is 400 mm. After floristic-physiognomic analyses,seven plant types were identified in the study area. About 360 plant samples were collected during 2010-2011 which belonged to 254 species, 187 genera, and 49 families. One hundred medicinal plant species were identified in the sample which belonged to 72 genera and 34 families. The result of the geographical dispersion analysis of the medicinal plants of the region indicated that the most frequent species were Irano-Turanian (63%) and Irano-Turanian and Saharao-Sidian (10%). Furthermore,the results obtained from life form analysis of the plants in this region revealed that the most frequent species belonged to the Therophytes (30%) and the Hemicryptophytes (30%) and the least frequent species were the Phanerophytes (12%).

Two hydroponic trials were conducted under controlled conditions to study the effect of sodium chloride salinity and nitrogen supply on two sunflower (Helianthus annuus L.) cultivars. A factorial experiment in completely randomized design (CRD) with 3 replications was carried out. The first factor included sunflower cultivars (i.e.,Alstar&Euroflore). The second and third factors (i.e., salinity & nitrogen levels) were established as 0, 50, 100, and 150 mM of NaCl and 0, 2, and 4 mM of NH4NO3, respectively. The sunflower cultivars were grown in aerated full-strength Hoagland solution. Salt and nitrogen treatments were added to the Hoagland solution jars at 2-leaves stage. After four weeks, the plants were harvested. The growth parameters including fresh and dry weights of shoots and roots, leaf number, leaf area, and the mineral elements including N, P, K and Na contents were determined. The results of variance analysis indicated that the growth parameters of the two sunflower cultivars decreased significantly with increasing the salinity levels, as compared to the untreated controls. It was observed that the low nitrogen level could ameliorate the effectsof different levels of salinity. In both sunflower cultivars, nitrogen and Sodium contents were increased in the roots with an increase in the salinity and nitrogen levels. Shoot potassium and phosphorus contents were decreased in Alstar and increased in Euroflor cultivars.

Alkali stress influences plant physiology at cellular and total levels through disturbing its ionic balance. In this study, the effects of different acidity (pH) treatments of irrigation water, in the alkalinity range, on the availability of the nutrients, nitrogen, and bicarbonate in the Nitrariaschoberi were investigated in the form of a completely randomized design. The design includedfive treatments (each treatment withfourreplications): control (pH7.2)and four levels of stress; that is, low alkalinity(LAK, pH8.5),moderate alkalinity (MAK, pH 9),high alkalinity(HAK, pH9.5), and strongly alkaline (SAK, pH 10). Data were analyzed using Minitab software (version 16), one-way ANOVA, and Tukey test at P

This study was conducted in an attempt toinvestigatethe effect ofAuxinhormones (IBA & NAA) andthe cultivation mediumon the rootingofhardwood cuttings of Myrtus (Myrtuscommunis). Afactorialexperiment was arranged incompletely randomized designwith threereplications. The first factor included different concentrations (i.e., 0, 1000, 2000, 3000, & 4000mg/l)of Auxin hormone(i.e., IBA & NAA) andthe second factor comprised different types of cultivation mediums(Sand, Perlite, &SandplusPerlite). Traitssuch asthe rooting percentage, the numberof rootin cuttings, the length and diameter of root, fresh weight of root,andthelongestrootsweremeasured. The results showed that theAuxintreatment had a significant effectonall of the evaluatedtraits whereas the effect of the cultivation medium was significant only on the length of the root. The highestpercentage ofrootedcuttings, rootnumber, root length, root diameter, fresh weight,androot lengthwas obtained from3000 mg/l of IBA treatment. Drawing on the results of this study, a treatmentof3000 mg/l IBA andperlitemediumforrooting in Myrtuscuttingsis recommended.

The present factorial study was carried out in a complete block randomized design with three replications to study the effects of Taravatsuperabsorbent hydrogel on the optimization of moisture content and improvement of rooting in Juniperusoblongacuttings. The treatments included four levels of hydrogel (i.e., 0 (control), 0.15, 0.3, & 0.6) and four irrigation intervals (1,2,3,& 4 days). The results of ANOVA indicated that different levels of irrigation and hydrogels and their interaction were significantly meaningful (at P≤0.01) for the indices of fresh and dry rootweights, root length, root width, root number per cutting, and the percentage of the rooted cuttings. Based on the comparison of means results, the individual consumption of hydrogel up to 0.3% significantly increased the rooting and improved the morphological characteristics of the cutting roots. The irrigation interval however had a negative effect on the rooting index of the plant. Comparing the results of the interaction effect of irrigation and hydrogel, it was observed that the highest rooting percentage (83.3%), fresh and dry root weight (4.8 & 3.5 g respectively),and root length and width (6.4 & 2.6 cm respectively) belonged to 0.3% hydrogel treatment with a two-dayirrigation interval which was significant (at P≤0.01) in comparison to the other treatments. On the basis of these results, it can be concluded that using 0.3% hydrogel of Super AB A 200 with a two-day irrigation interval not only produces cuttings with appropriate rooting but also scrounges 50% of limited irrigation water resources and other costs including the working costs compared to daily irrigation.

Recognizing the effect of ecological variables on biodiversity is essential for its conservation in rangeland ecosystems which is the main goal of natural resources management. Thus, this research was conducted to determine the diversity indexes and the edaphic (gravel percentage, bulk density, caco3 content, caso4 content, organic carbon, available potassium, available phosphorus, total nitrogen, sodium absorb ratio, electrical conductivity, pH,& soil texture parameters), climatic (precipitation &averageannual temperature) and topographic factors (elevation, direction,& slope) affecting these indexesin rangeland types of Asyabjofteh region in Kerman province. After developing the typology map of the rangelands in this region, the key area of each type was determined forsampling the existing species, vegetation coverage, and soil factors. The sampling of the vegetation coverage parameters was done by quadrate-transect method. Soil samples were collected from two horizons (0-15 & 15-30 centimeters) and were sent to laboratory to be analyzed for 14 soil parameters. These factors together with the climatic and topographic variables comprised the environmental matrix. Species diversity coefficients (i.e., Shannon & Simpson) and richness coefficients (i.e., Menhing&Margarof) were calculated in each vegetation type usingPastsoftware package. In order to determine the most significant factors affecting species diversity, the Principal Component Analysis (PCA) method was applied. The results indicated that the available potassium, sodium absorb ratio, bulk density, and caso4 content determine 47.6 % of variation in species diversity. These factors together with the texture and annual average temperature variables determined 68.3 % of variation in species diversity and were the most significant factors. Arthemisiaaucheri type had the lowest diversity coefficients because of the dominance of the prevailing species and Acer monspessulnum-Amygdaluselaeagnifolia type had highest diversity coefficients.

For timely utilization and achieving acceptable yield in each plant, determining the entry/exit time of the livestock, collecting the seed, and identifying the nutritional value of plant species are essential. These enable us to record and study the emergence of the biological phenomena is each plant, particularly the medicinal ones. In this study, different stages of the phenology of Ajugachamaecistuswere investigated in order to develop proper management programs for the study area and similar regions. This study was carried out in the semi-steppe rangelands of Kordanin Alborz province for threeyears (2008- 2010). Ten bases were selected from the plant species under study and the date of the vegetative and reproductive stages of the plant including: the vegetation and growth, flowering, seed maturation, and drying of the plant was recorded in specific forms during the growth season in 15-day intervals for three years. Additionally, the meteorological data and information including the average monthly temperature and the monthly precipitation related to each four-year under study were collected from the meteorological station closest to the region. On the basis of this data, the dry-period curve was drawn separately for each year from 2008 to 2010 to compare the phenology stages of the species under study. The results showed that considering the climatic conditions of the region, especially the environmental temperature (degree-day), this species begins its growth at different times in different years.