Abstract:

Based on the data collected from located observation, the relation between the quantity of soil microbe and soil factor was studied in the second rotation Chinese Fir plantation at Huitong, Hunan Province. The result shows that in the same watershed, the quantity of soil microbe on hillfoot is the most, the secondly is on hillside, and that on ridge is the least. At the same type of site, the quantity of microbe in 0～20 cm soil layer is the most, the secondly is in 20～40 cm soil layer, and the least is in 40～60 cm soil layer. The total of microbe and the quantity of bacteria reach the highest in autumn but the lowest in winner, while the quantity of fungi and actinomycetes reach the highest in summer, the lowest in winner and autumn. The total of microbe in Chinese chestnut forest soil is more than that in Chinese Fir plantation. The total of microbe is highly remarkable positive linear correlated with soil moisture content (P<0.01), the quantity of bacteria and actinomycetes are also remarkable positive linear correlated with it (P<0.05), while fungi do not correlate (P>0.05); The quantity of bacteria, fungi, actinomycetes and the total of microorganisms are not correlated with the soil temperature of the 10 cm soil depth (P>0.05); The quantity of bacteria, fungi and the total of microbe are highly remarkable positive linear correlated with soil organic carbon and soil total nitrogen content (P<0.01), and the quantity of actinomycetes shows remarkable positive linear correlated with soil organic carbon and soil total nitrogen content (P<0.05). The contribution ratio of the soil temperature, soil moisture content, soil organic carbon content and soil total nitrogen content to the quantity of soil microorganisms in Chinese Fir plantation range from 60% to 70%.

Key words: the second rotation Chinese Fir plantation, quantity of soil microorganisms, soil factor