Vegetation-Environmental Relationships and Ecological Species Groups of the Ilam Oak Forest Landscape, Iran

The study was carried out in the Ilam Oak forest that is located in the west part of Iran. The objective of this research was to determine the plant ecological groups and site classification in this region. Data were collected from 117 sample plots using the systematic-random sampling method. The size of sampling plots was 20 m?20 m for the tree and shrub species and 1.5 m ?1.5 m for herbaceous species. Whittaker?s nested plot method was used in order to record the herbaceous species. Soil samples were collected and analyzed to study soil properties. Multivariate analysis methods were used to classify and determine the relationship between species composition and environmental factors and to recognize ecological species groups. PC-ORD and SPSS software were used for data analyzing. Five ecological groups were specified in the study area. Cerasus microcarpa was the indicator species in the first group, which showed high correlation with carbon and nitrogen. Quercus brantii showed the strongest correlation with CaCO3. The third group was Acer monspessulanum. Elevation and clay were the most important factors that separated this group. Amygdalus orientalis showed high correlation with elevation. These two above mentioned groups were located in higher altitude. Astragalus liyciodes was the indicator species in another distinct group in the study region with high level of stoniness percentage. Astragalus group was observed where soil stoniness was high. Results also showed that groups at higher elevation showed lower richness.
 
REFERENCES
Barnes, B.V., Zak, D.R., Denton, S.R. and Spurr, S.H. (1998) For. ecol. John Wiley and Sons, Inc., New York, 774 p.
Basiri, P., Karami, R., Akbarinia, M. and Hosseini, S.M. (2004) Determination ecological species groups by using of Anglo-American method (Case study: Ghamishleh Marivan region). J. Environ. 34, 89-98 (In Persian).
Bergeron, S. and Bouchard, A. (1984) Use of ecological species groups in analysis and classification of plant communities in a section of western Quebec. Vegetatio. 56, 45–63.
Black, C.A. (1979) Methods of soil analysis. J. Am. Soc. Agron. 2, 771-1572.
Bredenkamp, G.J. (1986) Ecological profiles of potential bush encroacher species in the Manyeleti Game Reserve. South African J. Bot. 52, 53-59.
Brown, L.R., Bredenkamp, G.J. and Van Rooyen, L.N. (1996) The phytosociology of the northern section of the Borakalalo Nature Reserve. Koedoe. 39, 9-24.
Fisher, R.F. and Binkly, D. (2000) Ecology and management of forest soils.3rd Edn., John Wiley and Sons, INC, NY, 489 p.
 Fuls, E.R., Bredenkamp, G.J., Van Rooyen, L.N. and Theron, G.K. (1993) The physical environment and major plant communities of the Heilborn-LindleyEarden-Villiers area, northern Orange Free State, South Africa J. Bot. 59, 345-359.
Godart, M. (1989) Ecological species groups in forest communities in South Belgium. Vegetatio. 81, 127– 135.
Goebel, P.C., Palik, B.J., Kirkman, L.K., Drew, M.B., West, L. and Pederson, D.C. (2001) Forest ecosystems of a Lower Gulf Coastal Plain landscape: multifactor classification and analysis. J. Torrey Bot. Soc. 128, 47-75.
Hassanzad, N.I., Namiranian, M. and Zahedi, G.A. (2004) An evaluation of relationship between quantitative and qualitative characteristics and site factors in the natural beech (Fagus orientalis) stands in Asalem. Iranian J. Nat. Res., 57, 235-248 (In Persian).
 Hix, D.M. and Pearcy, J.N. (1997) Forest ecosystems of the Marietta Unit, Wayne National Forest, southeastern Ohio: multifactor classification and analysis. Can. J. For. Res. 27, 1117-1131.
Host, G.E. and Pregitzer, K.S. (1991) Ecological species groups for upland forest ecosystems of northwestern Lower Michigan. For. Ecol. Manage. 43, 87-102.
Host, G.E. and Pregitzer, K.S. (1992) Geomorphic influences on ground–flora and overstory composition in upland forests of northwestern Lower Michigan. Can. J. For. Res. 22, 1547–55.
Jafari, M., Zare, C.M.A., Tavili, A., Azarnivand, H. and Zahedi, A.G. (2004) Effective environmental factors in the distribution of vegetation types in Poshtkouh rangelands of Yazd Province (Iran). J. Arid Environ. 56, 627–641.
Jalilvand, H., Kooch, Y., Bahamnyar, M.A. and Pormajidian, M.R. (2007) Ecological Species groups of Hornbeam forest ecosystems in southern caspian (North of Iran). J. Bio. Sci. 7, 1504-1510.
Kashian, D.M., Barnes, B.V. and Walker, W.S. (2003) Landscape ecosystems of northern Lower Michigan and the occurrence and management of the Kirtland’s warbler. For. Sci. 49, 140-159.
Konollova, I. and Chytry, M. (2004) Oakhornbeam forests of the Czech Republic: Geographical and ecological approach to vegetation classification. Preslia, Praha. 76, 291-311.
Kooij, M.S., Bredenkamp, G.J. and Theron, G.K. (1990) Classification of the vegetation of the Bland type in the North- Western Orange Free State. South Africa J. Bot. 56, 306-318.
Mahmoodi, J., Zahedi Amiri, G.H., Adeli, E. and Rahmani, R. (2005) An Acquaintance with the relationship between plant ecological groups and the soil characteristics in a Kelarabad Plain forests (In North of Iran). Iranian J. Nat. Res., 58, 351-362.
McCune, B. and Mefford, M. (1999) Multivariate analysis of Ecological data version 4.17.M.J.M software. Glenden Beach, Oregon, USA, 233 p.
Moustafa, A.A. and Zaghloul, M.S. (1996) Environment and vegetation in the montane Saint Catherine area, South Sinai, Egypt, J. Environ. 34, 331-349.
Müller-Dombois, D. and Ellenberg, H. (1974) Aims and methods of vegetation ecology. John Wiley and Sons. New York, NY, 547 p.
Munhoz, C.B.R., Felfili, J.M. and Rodrigues, C. (2008) Species-environment relationship in the herb-subshrub layer of a moist savanna site, Federal District, Brazil. Braz. J. Bio., 68, 25-35.
Pabst, R. J. and Spics, T. A. (1998) Distribution of herbs and shrubs in relation to landform and canopy cover in riparian forests of coastal Oregon. Can. J. Bot. 76, 298-315.
Regato-Pajares, P. and Elenna-Rosselo, R. (1995) Natural Black Pine (Pinus nigra Subsp Salzmanii) Forest of Iberian Eastern Mountains: Development of the Phytoecological Basis for their Site Evaluation, Ann. Sci. For. 52, 589-606.
Rowe, J. S. (1956) Uses of undergrowth plant species in forestry. Ecology. 37, 461–473.
Salehi, A., Zarikafsh, M., Zahedi Amiri, G.H. and Marvi Mohajer, M. (2005) A study of soil physical and chemical properties in relation with ecological groups in Namkhaneh district of Kheirod-kenar forest. Iranian J. Nat. Res., 58, 567- 577 (In Persian).
Schoenholtz, S.H., VanMiegroet, H. and Burger, J.A. (2000) A review of chemical and physical properties as indicators of forest soil quality: Challenges and properties. For. Ecol. Manage. 138, 335-356.
Scott, R. A and Covington, W. W. (2006) Vegetation–environment relationships and ecological species groups of an Arizona Pinus ponderosa landscape, USA. Plant Ecol. 185, 255-268.
Simpson, T. B., Stuart, P. E. and Barnes, B. V. (1990) Landscape ecosystems and cover types of the reserve area and adjacent lands of the Huron Mountain Club. Occasional Papers of the Huron Mountain Wildlife Foundation. No. 4., 128 p.
Spies, T.A. and Barnes, B.V. (1985) A multifactor ecological classification of the northern hardwood and conifer ecosystems of Sylvania Recreation Area, Upper Peninsula, Michigan. Can. J. For. Res. 15, 949-960.
Van-der-Marrel, E. (1979) Transformation of cover-abundance values in phytosociology, its effects on community similarity. Vegtatio. 39, 97-114.
Vandvik, V. and Ohn, H. (2002). Partitioning floristic variance in Norwegi and upland grasslands into within-site and betweensite components: Is the pattern determined by environment or by landuse. Plant Ecol. 162, 233-245.
Whittaker, R. H. (1956) Vegetation of the Great Smoky Mountains. Ecol. Monog. 26, 1-80.
Zahedi Amiri, Gh. (1998) Relation between ground vegetation and soil characteristics in a mixed hardwood stand. PhD Dissertation, University of Ghent, Begum Academic Press, 319 p.
Zahedi, A.G.H. and Limaei, S.M. (2002) Relationship between plant ecological in herbal layer and forest stand factors (case study: Neka forest, Iran) . Iranian. J. Nat. Resour. (In Persian). 55, 341-353.
Zarinkafsh, M. and Rezaee Kalantari, A. (2006) A study on soil characteristics of Hyrcanian Forest associsted with plants communities. Iran. J. Nat. Resour. 1, 15-28.
Zogg, G. P. and Barnes, B. V. (1995) Ecological classification and analysis of wetland ecosystems, northern lower Michigan, U.S.A. Can. J. For. Res. 25, 1865–1875.