指出目前小张庄村生态系统是稳定的，但效率低。
It points out that the precent ecosystem in Xiaozhangzhuang village is stable but inefficient .
安徽省颍上县小张庄村人口问题的研究
A study on the population problem in Xiao Zhang Zhuang village , Ying , shang county , Anhui Province
张庄村