Identification of flora in each region, plays an important role in maintaining the national reserves of each country. This study was carried out to identify the species, life form and geographical distribution of plants in Vezg region, which is located at Southeastern of Yasouj, in south-west of Iran (E 51°, 39', 55''-51°, 41', 10'' , N 30°, 30', 35''-30°, 32', 0'')). In this study, 122 flora species belong to 102 genera and 32 families were surveyed from April 2010 to August 2011. The life form spectrum was determined using Raunkierʼ s system and compared with his normal spectrum. The herbaceous/woody species ratio was 7.13. The families with the greatest number of species were Compositae (17), Umblliferae (13), Labiatae (12), Caryophyllaceae (10) and Cruciferae (10). The observed life-form spectrum was: Therophytes (45.9%), Hemicryptophytes (32%), cryptophytes (9.8%), Phanerophytes (9.01%) and Chamaephytes (3.27%). In geographical distribution, the most frequency was 72.95% (89 species) that belongs to Irano-Turanian zone. Results showed that therophytes and hemicryptophytes were more than and phanerophytes and chamaephytes were less than the normal spectrum. Our findings are in agreement with data obtained in arid and semi-arid climates.

Flora, Life Form and Geographical Distribution of Plants in West-South Forests of Iran (Case Study: Vezg, Yasouj)

Livestock grazing can affect the cycling of nutritional elements in soil by making changes to the vegetation coverage. This study aimed to investigate the effect of rangeland exploitation on vegetation coverage and nitrogen kinetics. To this end, three experimental sites of light, moderate, and heavy grazing in Nodoushan rangelands of Yazd province were selected. The vegetation properties were then measured through systematic random sampling method and three to five bases along the transect were sampled from the current year growth of the dominant plants in the region. The soil samples were collected from 0–15 cm depth in five replications and mixed together to obtain a single composite soil sample on each site. In the first stage, nitrogen (N), carbon (C), C/N, cellulose, hemicellulose, and lignin of the sampled plant as well as nitrogen, carbon, lime, soil texture, saturation moisture percentage, pH, and electrical conductivity (EC) of the soil were measured. As the soil properties did not differ for light and moderate grazing soils, different treatments were conducted on the dominant species of light and heavy grazing sites with 1% organic carbon added to the rangeland soil. Nitrogen mineralization treatments were selected based on vegetation changes that, with increasing livestock grazing intensity, changed the predominance of plant composition from Artemisia sieberi and steppe to percentage Artemisia sieberi and Peganum harmala. The treatments included control, 100% Artemisia sieberi, 75% Artemisia sieberi and 25% Peganum harmala, 50% Artemisia sieberi and 50% Peganum harmala, 25% Artemisia sieberi and 75% Peganum harmala, and 100% Peganum harmala. The soil samples were incubated for pure nitrogen mineralization in three replications of 3 months. The results of nitrogen mineralization revealed that the immobilization of the treated soil with higher Artemisia sieberi and lower Peganum harmala was done at a more rapid rate during the first week. The immobilization was slowly reduced by the third week and then followed a growing rate. Overall, the results show that an increase in grazing intensity was associated with a change in vegetation coverage toward Peganum harmala species, the biochemical characteristics of which elevated the levels of pure nitrogen mineralization in soil.

https://www.mdpi.com/2071-1050/13/15/8392/pdf

The Effect of Grazing Intensity on Vegetation Coverage and Nitrogen Mineralization Kinetics of Steppe Rangelands of Iran (Case Study: Nodoushan Rangelands, Yazd, Iran)

Determination the most important variations in plant traits related to livestock grazing using multivariate statistical methods in Baladeh-Noor rangeland, Mazandaran Province, Iran

Karimi Ghader

Papers

Effect of range and livestock management on vegetation of Margon station in Kohkiloyeh and Boyerahmad province, Iran.