Abstract: The study on the growth and physiological traits of Alternanthera ph iloxeroides in a water culture under stress of different concentration Cu show ed that Cu stress inhibited the normal growth of A. philoxeroides. When the Cu concentration was <5 mg·L-1, the plant cellular SOD, POD, and CAT acti vities increased; when the Cu concentration was >5 mg·L-1, the plant grow th slowed down, the biomass, chlorophyll content, and SOD, POD and CAT activitie s decreased, and in addition, the cell membrane permeability increased and MDA h ad a higher accumulation, giving adverse impact on the plant normal growth and m etabolism; when the Cu concentration was 10 mg·L-1, a severe apparent dam age to the plant was observed.

Key words: Chinese fir plantation, Soil active organic matter, Microbial biomass C, Water-soluble organic C, Water-soluble carbohydrate