as the management term of pure bamboo stands prolonged the natural soil fertility declined, which resulted from the growth characteristics of pure bamboo forest and the management methods.
毛竹纯林随经营期的延长,其土壤的自然肥力呈下降趋势,这是毛竹纯林的生长特性和经营方式决定的。
natural soil fertility is dropping in many areas because of continuous industrial fertilizer and pesticide use, while the growth of algae is increasing in lakes because of the fertilizer run-off.