Document Type : Research Paper

Authors

• Mostafa Naderi ¹
• Asghar Mosleh arany ²
• Gholamhosein Moradi ³
• Abdosalam Piri ⁴
• Mehrdad Kuhzadian ⁵
• Hamid Azimzadeh ³

¹ MSc. Student, Faculty of Natural Resources, Yazd University, IR.IRAN

² Associate Professor, Faculty of Natural Resources, Yazd University, IR.IRAN

³ Assistent Professor, Faculty of Natural Resources, Yazd University, IR.IRAN

⁴ MSc., Natural Resources and Watershed Management Office of Ilam Province.

⁵ MSc., Natural Resources and Watershed Management Office of Ilam province.

Abstract

This research aimed at studying the vegetation and investigating the effects of physiographic,
edaphic and geological factors upon distribution of plant communities in Manesht district in Ilam
province. Sampling was done based on plant types and land unit map. The number of samples was
determined by Krebs method. In total, 125 square sampling plots of 400 2 m area were selected by
random systematic method. To determine soil factors, two soil samples (0–30, 30-90 cm deep) were
collected from each land unit and physico-chemical parameters were measured. Using TWINSPAN,
vegetation of study area was classified and then PCA and CCA were used to investigate the
relationship between vegetation and environmental factors. Based on TWINSPAN, four vegetation
groups were recognized. According to TWINSPAN results, four ecological groups were identified
that first and second groups with 31 and 46 sample plots, respectively and by Quercus barantti,
Crataegus pontica and Acer monspessulanum, as indicator species, are more calciphiles than
another groups. The first three axes of the PCA accounted for 62.83%, 23.45% and 13.72% of the
total plant cover variability, respectively. Also based on Mont Carlo analysis, first and second axes
with 0.68 and 0.48 eigenvalue, accounted for 28% and 19% of the variability, respectively and the
correlation coefficient of axes and species is 0.98. According to PCA and CCA, Formation, organic
matter and lime were the most important factors on establishing of ecological groups.

Keywords

• Canonical correspondence analysis
• Manesht protected area
• principal components analysis
• Two-Way Indicator Species Analysis