Abstract: The relations between the growth and yield of Chinese fir and ecological factors—climate,soil and topography were discussed, Some unfavorable effects of repeated plantation of Chinese fir on the environment were also analysed, To protect the ecological balance and increase the productivity of Chinese fir,the authors suggest that it is necessary to do some experiments for changing the pure plantation to mixed one with broad-leaved trees.

Key words: Poplar-wheat intercropping systems, Microclimatic effect, Soil moisture