Abstract: A laboratory experiment with the soil samples collected from a pure Manchurian walnut plantation was conducted under juglone addition and soil sterilization to study the interactions between added juglone and soil microbes. After soil sterilization, the decomposition rate of added juglone decreased obviously. On the 5th day of incubation, only a few of the added juglone (6.07% of the total) was found in unsterilized soil, and the remained juglone in sterilized soil occupied 42.92% of the total. After juglone addition, the total quantity of soil PLFAs decreased significantly, and the growth of soil gram-positive bacteria, gram-negative bacteria, fungi, and actinomycetes was all inhibited. This study demonstrated that soil microbes facilitated juglone decomposition, while juglone had inhibitory effects on the growth of soil microbes.

Key words: slope aspect, curvature, altitude, slope degree, leaf area index, habitat type.