Studies on the seasonal changes of soil enzyme activity in Robinia pseudoacacia and Ailanthus altissima mixed stands in coastal saline soil.

The soil enzyme activities of different soil layers at different seasons in pure and mixed stands of Robinia pseudoacacia and Ailanthus altissima were studied.The results indicated that there were differences among different stands on soil enzyme activities at different season and soil layers,it's also shown that the distributions of the soil enzyme activities in different soil layers had some regularity,totally,the soil enzyme activities decreased gradually with the soil layer depth decreasing.Also,the tree growth and the soil enzyme activity of mixed stand were all better than that of the pure stands.