Study of Physical and Chemical Soil Properties Variations Using Principal Component Analysis Method in the Forest, North of Iran

The field study was conducted in one district of Educational-Experimental forest at Tehran University (Kheirood-Kenar forest) in the North of Iran. Eighty-five soil profiles were dug in the site of study and several chemical and physical soil properties were considered. These factors included: soil pH, soil texture, bulk density, organic carbon, total nitrogen, extractable phosphorus and depth of soil. Principal Component Analysis (PCA), was used to identify the variations of soil properties. Results showed that there are significant relationships between some soil factors and two PCA axes. Content of clay in A1 and A2 horizons, bulk density, organic carbon and total nitrogen in A1 horizon, and content of silt in A2 horizon, correlated to the first PCA axis. Content of clay, pH, carbon percentage and silt content of B1 Horizon, and soil depth, were the most important factors correlated to the second PCA axis. Soil profiles that consist high content of clay, with heavy soil texture, and soil profiles with high content of silt, occupied different areas in the forest. The content of total nitrogen and organic carbon also varied noticeably amongst the soil profiles. The variations of soil properties showed correlation with the distribution of trees and variations of altitude.
 
REFERENCES
Asly, A and Etter, H. (1969) Forest Management Plan for EducationalExperimental Forest of Tehran University. Tehran University, Tehran. pp. 3- 10.
Salehi and Zahedi 137 Brady, N. C and Weil, R. R. (1990) The nature and properties of soil (Tenth edition0 macmilan publishing company, 621 p.
Cornelissen, J. H. C, (1996) An experimental comparison of leaf decomposition rates in a wide range of temperate plant species and types. J. Ecol., 4, pp. 573- 582.
Edwards, C. A., D. E. Reichk and A. Crossley, (1970) The role of soil invertebrates in turnover of organic matter and nutrients. Springer- Verlog, New York: pp. 147- 172.
Finzi, A. C. , Breemen, N. V., Canham, C. D. (1998) canopy tree-soil intraction whitin temperature forests: speices effects on carbon and nitrogen, Ecological application, 8, 440- 446
Fisher, R. F and Binkley, D, (2000) Ecology and Management of Forest Soils (Third edition), John Wiley & sons, INC, 489 p.
Gerrard, A. J, (1981) Soils and landforms. George Allen & Unwin Ltd, 219 pp. Goldsmith, F. B. (1973) The vegetation of exposed sea cliffs at South Stack, Anglesey. Ι. The multivariate approach. J. Ecol., 61, 787- 818.
Goodall, D. W. (1954) Objective methods for the classification of vegetation. III. An essay in the use of factor analysis. Australian J. of Botany, 2, 304- 324.
Gorji Bahri, Y, (1988) Quantitative and qualitative evaluation of Quercus/ Carpinus stands in Kheyrood-kenar forest, Msc thesis, Tehran University press, 47 p.
Habibi, H, (1974) Investigation of influence of soil texture on Beech trees’ growth rate in Iran. Journal of Iranian Natural Resources, 31, 61- 69.
Habibi, H. (1984) Study of the soils in beech forests of Iran and their role in distribution of different beech type. Journal of Iranian Natural Resources, 38, 1- 15.
Habibi, H, (1992) Investigation of Hornbeam’s forest soils in Mazandaran province and its roles in quality of forest stands. Journal of Iranian Natural Resources, 38, 17-25.
Hill, M. O., Bunce, R. G. H., Shaw, M. W., (1976) Indicator species analysis, a divisive polythetic method of classification and its application to a survey of native pine woods in Scotland. J. Ecol. 63, 597-613.
Kent, M and Coker, P (1996) Vegetation Description and Analysis, A Practical Approaches. John Wiley & sons, 650 pp. Lorphelin, L. and kichi, P. (1987) the soil of the typical slope in the Himalayas (Nepal); their main characteristics and distribution. Catena, 146, 533- 550
Makarov, M. I., Malysheva, T. I., Haumaier, L., Alt, H.G and Zech, W., (1997) The forms of phosphorus in Humic and Fulvic acids of a toposequence of alpine soils in the northern Caucasus. Geoderma, 80, 61- 73.
McCune, B. (1997) Influence of noisy environmental data on canonical correspondence analysis. Ecology, 78, 2617- 2623.
Mesdaghi, M, (2000) Vegetation description and analysis: a practical approach. Jehad Daneshgahi of Mashhad, Mashhad, pp. 161- 179.
Moghadam, M. R, (2000) Quantitative Plant Ecology. Tehran University, Tehran, pp. 233- 279.
Pourbabaei, H, (2004) Statistical Ecology. Guilan University, pp. 293- 319.
Salehi, A. (2004) Investigation of physical and chemical soil properties variations in relation to trees composition and topographic factors in Nam-Khaneh district of educational-Experimental forest of Tehran University (Kheirood-Kenar forest).  PhD Dissertation, Tehran University, Tehran. 187 p.
Sarmadian, F and Jafari, M (2001) Investigation of forest soil in EducationalExperimental forest of Tehran University. Journal of Iranian Natural Resources, Special Issue, 111p.
Schoenholtz, S. H, Van Miegroet, H, Burger, J. A (2000) A review of chemical and physical properties as indicators of forest soil quality: challenges and opportunities. Forest ecology and management, 138, 335-356.