e. zandi esfahan

Recognizing the environmental factors affecting plants structural trials and biomass is important to conserve plants as well as their ecosystem function, and services. Onobrychis aurea is a valuable forage that is distributed in the marl lands and is considered as an endangered plant species in Iran. In the present study, the ecological characteristics (plant traits) of this species has been investigated in detail.

For this purpose, structural traits and biomass of O. aurea were investigated in 12 ecological units with different topographical and soil conditions. Three soil samples were taken to 15cm depth, (0-15cm) in each ecological unit. The relationship between structural traits and species biomass with environmental factors was tested by redundancy analysis (RDA) method in 2016.

The results indicated that the soil characteristics including clay, lime and silt content play a more important role in the structural and biomass traits of O. aurea evidence show. Spatial and topographical factors, especially elevation and geographical aspects, had a smaller contribution in structural traits and species biomass in comparison with soil factors. Higher structural values were recorded in heavy textured alkaline soils. The slope percentages also have no significant effect on plant characteristics.

The present study indicated that the soil and topographic factors are very important for management of O. aurea. In general, it should also be emphasized that having good knowledge related to plant ecology as well as environmental condition could help managers to conserve and rehabilitate endangered plants.

Identification and cultivation of new oilseeds is an important step in supplying the oil needed in the country. Regarding the vastness of saline areas in the country, the cultivation and exploitation of salinity-resistant plants under saline conditions of both water and soil can be an appropriate option in the field of production and extraction of oils from salinity-resistant plants. The aim of this study was to determine the percentage of extractable oil and the compounds of fatty acids in two halophyte species Salicornia europaeae and Halocnemum strobilaceum on the shores of Lake Urmia. For this purpose, the seeds of the species were collected in autumn of 2016. Fatty acids were extracted by solvent. The solvent-oil mixture was separated by rotary vacuum distiller, and after methyl ester preparation and injection into the gas chromatography (GC), fatty acids were analyzed. To identify the fatty acids, a standard mixture of fatty acids (Sigma Co.) and their inhibition times were used. Data were analyzed by SPSS software using independent t-test. The mean oil yields of two species of S. europaeae and H. strobilaceum was obtained 18.58 and 9.28%, respectively. In total, 12 fatty acids including lauric acid (C12: 0), merisitic acid (C14: 0), myristoleic acid (C14: 1n5), palmitic acid (C16: 0), palmitoleic acid (C16: 1n7), stearic acid (C18: 0), oleic acid (C18: 1n9), linoleic acid (C18: 2n6cis), α-linolenic acid (C18: 3n3), g-linoleic acid (C18: 3n6), and arachidic acid (C20: 0) were recorded in the profiles of these two species. Linoleic acid was the most major unsaturated fatty acid in S. europaeae and H. strobilaceum, at 56 and 54.7%, respectively. Palmitic acid was also predominant saturated fatty acid in S. europaeae and H. strobilaceum, at 11.4 and 9.7%, respectively. The results showed that according to the oil yield (18.58%) and percentage of saturated and unsaturated fatty acids identified, S. europaeae seeds could be evaluated as a source of edible oil.

In order to determine the reciprocal relationship between the important characteristics of soil and the growth of Haloxylon ammodendron (C.A. Mey) plant in segsi plain of Isfahan., ordination method was used. The study was performed through the stratified random sampling and the regions were separated according to the plant age and physical physiognomy, then 10 samples of Haloxylon ammodendron (C.A. Mey) of the same age were selected in each region. Meanwhile, factors such as height, canopy cover area, canopy cover perimeter, canopy cover diameter, and basal area were considered. Also, 30 profiles from viewpoint of growth situations in 10 different regions were dug. Soil characteristics such as : pH, Ec, total soluble Ca2+ and Mg2+, Cl-, CO3--, HCO3-, SP%, CaCO3%, CaSO4%, organic matter%, total nitrogen percentage, phosphorous, Na+, K+, SAR, and hardpan depth were measured. Data was analyzed using ordination method. According to the results, samples of the same age showed significant differences in plant features. Other results showed that physical characteristics such as depth of hardpan from soil surface, SP%, and chemical characteristics such as salinity, alkalinity and total nitrogen had the highest effect on qualities of this kind of plant. In other words, the results mentioned above showed the important role of Haloxylon ammodendron (C.A. Mey) in sharp increase of salinity and alkanity in it's stratum.