Composition and structure of species along altitude gradient in Moghan-Sabalan rangelands, Iran Composition and structure of species along altitude gradient in Moghan-Sabalan rangelands, Iran

回到完整页面

Vol15 No.6: 1209-1228

Title】Composition and structure of species along altitude gradient in Moghan-Sabalan rangelands, Iran

Author】Sahar GHAFARI1; Ardavan GHORBANI1*; Mehdi MOAMERI2; Raoof MOSTAFAZADEH1; Mahmood BIDARLORD2

Addresses】1 Department of Range and Watershed Management, University of Mohaghegh Ardabili, Ardabil, 5619911367, Iran; 2 Department of Plant Sciences and Medicinal Plants, University of Mohaghegh Ardabili, Ardabil 5619911367, Iran

Corresponding author】Ardavan GHORBANI

Citation】Ghafari S, Ghorbani A, Moameri M, et al. (2018) Composition and structure of species along altitude gradient in Moghan-Sabalan rangelands, Iran. Journal of Mountain Science 15(6). https://doi.org/10.1007/s11629-017-4820-2

DOI】https://doi.org/10.1007/s11629-017-4820-2

Abstract】This study provides a checklist of species distributed at the altitude gradient of Moghan-Sabalan rangelands in Ardabili province, Northwest Iran. We evaluated the changes in species composition, growth types of species, Raunkiaer's life forms, geographical distribution, threat and endemicity status, and palatability of species along two altitudinal gradients in the sampling plots, which were conducted in eleven sites/habitats with 300 meters above sea level (masl) altitude intervals (from 100 to 3300 masl). We assessed the plant species composition with special reference to the gradient analysis, and identified overall 396 species, which was comprising 44 families and 194 genera. Results showed that Asteraceae family is by far the most species-rich family, followed by Poaceae, Fabaceae, Caryophyllaceae and Brassicaceae. Among the genera, Astragalus is the most diverse genus, followed by Allium, Veronica and Bromus, Galium, Silene and Ranunculus. Results indicated that the number of species increased as the altitude increased to 1200-1500 masl, but then starts to decline to 3300 masl. Family-to-genera ratio was 1:4.4, the family-to-species ratio was 1:9, and the genera-to-species ratio was 1:2.04. Growth type of species analysis shows that the frequency of perennial plants was higher in the study area followed by annual species while the lower group was biennial species. The number of annuals showed a decreasing trend towards higher altitude. Hemicryptophytes and therophytes were the most frequent life forms constituted each with (41.9%). Hemicryptophytes showed an increasing trend with altitude, while therophytes showed a decreasing trend with altitude increase, followed by geophytes, chamaephytes, and phanerophytes. Results showed more than half of the species of the study area belonged toIran-Turanian region and these species showed an increasing trend with altitude. In contrast, Sahara-Sindian species comprise a minor component of the spectrum, with decreasing trend with altitude. The rare and endangered species out of the surveyed taxonomic groups comprised 53 species in total which 29 of them are considered lower risk (LR), 13 data deficient (DD), 5 vulnerable (Vu) and with 3 rare (R) and identified endemic plants comprised 24 species. Some 56.6% species were identified as class III, 22.6% were class I and 20.8% were class II as the palatability variation. Moghan-Sabalan rangelands require strong conservation management policies in case of species loss and changing natural communities due to the occurrence of conversion into cropland, over-grazing and other anthropogenic effects.

Keywords】Flora; Floristic diversity; Species distribution; Elevation; Red data categories; Endemic; Ardabili province