[Effect of human activities on soil environment and plant species diversity of elm sparse woods]

Human activities have a major impact on the biodiversity of the earth, while biodiversity change is considered as an important global change in its own right. Elm sparse woods is a climax community distributed on the sandland in temperate steppe zone. Its habitat conditions are much more fragile, and are easily destroyed. Our studies on the effect of human activities on soil environment and plant diversity showed that the main soil environmental factors and plant species diversity had some obvious changes, of which, the changes of man-made pine woods and heavy grazing disturbance were the largest, and the of man-made poplar woods were the in those next place. It is suggested that natural laws and consistency of ecosystem processes in the low and long temporal scale should be considered adequately in the environment management of sandland.