Seasonal Variation in Major Soil Nutrients and Microorganisms at the Plantations of Pinus koraiensis S. et Z. Following Clearcut of Quercus mongolica Fisch.

Abstract

Seasonal variation of the soil microorganisms involved in carbon and nitrogen mineralization and major soil nutrients such as nitrogen and phosphorus were investigated in a 30-year-old Quercus mongolica Fisch. stand and in 8-, 18-and 28-year-old Pinus koraiensis S. et Z. plantations following clearcut of Quercus mongolica Fisch. stand and in 8-. 18-and 28-year-old Pinus koruiensis S. et Z. plantations following clearcut of Quercus rnongolica Fisch. This study was conducted at the Seoul National University Forests placed along Mt. Taewha located in Sanglim-lee, Docheok-myon, Kwangju-gun, Kyonggido. Korea. Seasonal variation in soil physicochemical conditions was greatly fluctuated at 8-year-old Pinus koruiensis plantation than at other stands due to clearcutting. The factors which were significantly different among those stands were contents of total N, C, P, soluble salts, moisture and ammoniun N. and pH. Total nitrogen and available phosphorus gradually decreased after clearcutting, but were recovered after about 20 years. Contents of moisture, ammonium N, soluble salts and total carbon were reduced by the clearcut, but the maturation of the stand improved soil conditions at all of the stands. The populations of soil microorganisms involved in carbon and nitrogen mineralization were not significantly changed by the clearcut. Thus. the establishment of P. koruiensis plantation following clearcut of Q. mongolicu changed total nitrogen and carbon contents, but did not disturb greatly the forest soil condition.